Karibu kwenye blog ya kijanja na yenye mautundu ya kutosha. Jivinjari kwa ku-download madude kibao kutoka kwenye hii blog.
        Unaweza download vitu mbalimbali kama;

Tembelea page uipendayo ili ujivinjari.






  • F/MBus cable connector pinout:
  • GND - Ground
  • TX - Data send
  • RX - Data receive
  • RX2 - ?
  • MBUS - MBUS data exchange protocol
  • FBUS - FBUS data exchange protocol
  • VPP - Programming power supply
  • VCC - Common collector voltage
  • VBUS - VBUS, USB powerdetect


    • Battery connector pinout:


    • GND - Ground (Attention, this is not system GND)
    • VBAT+ or VCC - Battery positive
    • BSI - Battery Size Indicator
      Email me for any mobile repair questios I will replay to you on time

how to use D+ and D- (USB) as serial Rx and Tx

I found a wired fact that all my serial ports of mbed board are not working!!!!... I guess this happened due to my own fault. I tried to connect to Max232 IC with out taking the ground pin (For common ground) of mbed. So i have only one go i.e to use USB pins 31 and 32 as serial ports for wireless transmission. Can anyone help me out??? How to use this two pins???

 This ABSOLUTELY fixed my AT&T Note 3's GPS. However: :::: DISCLAIMER :::: I had an unusual chain of events leading up to this fix. I hope it fixes your Note 3's GPS, but there's really no way to tell - unless you decide to try it. It may not help you at all. So, what have you got to lose? Well, take a look at [[ WILL THIS HELP YOU? ]] and [[ RISKS ]].

[ INTRO ]]
 If you're here, most likely your Note 3's GPS doesn't work, and you're desperate like I was for a fix. Here's the chain of events that led to my fix: 1. Got AT&T Note 3 - **out of the box** it had the 'blurry' camera issue, but outstanding GPS (consistent 3 second satlock). 2. Sent Note 3 in for Samsung Warranty Repair to fix the 'blurry' camera. 3. Samsung fixed the camera. 4. Disappointingly, Samsung broke the GPS (by bending the 'leaf' pin circled RED in my pic below, I assume inadvertently during reassembly). 5. Got Note 3 back - camera fixed, GPS broken by Samsung. 6. After observing an iFixit teardown, I followed this chain of logic: A - Since Samsung replaced my camera, and B - the camera is separate from the main board that the GPS is on, then C - Samsung must have only replaced the camera, and left the GPS alone. D - Therefore, Samsung did not replace my exceptional GPS, that, sadly, is now broken. E - Something else must have broken the GPS. F - I read a thread suggesting that tightening the 12 screws on the back fixes the GPS, then G - I decided it's time to check on the leaf pins after looking at the iFixit teardown. Below is what I found.
[[ WILL THIS HELP YOU? ]] Hopefully. I have no idea. Maybe. Decide if the [[ RISKS ]] are worth it to find out if one of your 'leaf' pins are bent or damaged (mine was bent by Samsung Warranty Repair, as explained above).

[ 1 ] Yes, if one of the 'leaf pins' is bent, dislodged, or otherwise not making contact.

 [ 2 ] Yes, if one of the contacts that the leaf pins touch is oxidized. (Remove oxidation by scraping it off.) --- Thanks to evilpotatoman for reporting this fix! ---

 [ 3 ] Yes, if one of the 'leaf pins' is squished and is not pressing hard enough against the contact. (Bend "leaf pin" outward to make tighter contact.) --- As suggested by evilpotatoman --- Also, perhaps adding a small piece of stock paper under the offending leaf pin will make it keep contact better. ( !!!! Be careful - don't add too much paper, which could stress the pin or contact !!!! ) --- As suggested by superdookie67 --- [4] Yes, if a screw is loose. This may happen if you remove the back cover frequently, which loosens the screw that keeps a solid connection between the leaf pin and contact near the back cover fingernail hole. --- As suggested by yedidi2006 --- Let's be honest: since Samsung Warranty Repair dislodged my Note 3's leaf pin, isn't it plausible that a maybe even a few Note 3's shipped with bent leaf pins? I'M WILLING TO BET YES. So please reply and let everyone know if this fixes it. [[ RISKS ]] (Honestly, this is a pretty basic procedure. But here goes)

1. Potentially voiding warranty, though I have no idea how it can be proven (put some new Loctite on the screws afterward if you're paranoid.)

2. (Only a risk for those who are completely careless) Potential damage to internal equipment. 3. Losing 30 minutes of your life. Personally, I love tearing stuff apart whenever I have an excuse, so for me this wasn't a risk.

 [ INSTRUCTIONS ]] (See attached pics for details) 

1. See your favorite teardown site for even more details. Remove the back cover, stylus, SIM, and microSD.

2. Remove the 12 Phillips screws on the back. They are sealed with Loctite, so don't damage your phone with too much force.

3. !!!Carefully!!! remove the inner plastic shell (clipped in). 3a. !!!Only lift up!!!, perpendicularly from the screen to avoid damaging the leaf pins. 3b. !!!Take your time!!! Gently open around the edges until all edges and clips are loose.

4. Observe the leaf pin locations shown below.

5.  Samsung bent my leaf pin circled in RED below. This one is clearly related to the GPS, becausebending   it back restored my GPS to perfect functionality.

6. !!!!Extra Carefully!!!! bend the leaf pin back into position, if you find a dislocated leaf pin.

7. Replace the inner plastic shell, making sure to not damage the leaf pins.

8. Replace the 12 screws (with new Loctite, at your discretion).

9. Obviously, replace the SIM, microSD, stylus, and back cover.

10. Fire it up.

11. MOST IMPORTANTLY, reply back if this helps - maybe this is a fix for many of the Note 3's that shipped with terrible GPS reception.

 How To Root Samsung Galaxy On8 Without Pc?

How To Root Samsung Galaxy On8 Without Pc? April 3, 2017 Jagmohan Singh NegiAndroid, Root Hi friends ,if you are a Samsung Galaxy ON8 user and want to root samsung galaxy on8 without pc then stop your search here and dont waste your time to find a way to root your Samsung on 8 without pc.
          Till now there is no any method to root Samsung galaxy On8 with pc or without pc.
 As we all know XDA is a biggest and faithful android developer’s website and till now there is no any clue to root Samsung galaxy on8 without pc or with pc. so don’t try any one click root app like king root ,kingo root,farmaroot and iroot app etc.because samsung galaxy on8 is more secure and till now any root method is available for Samsung galaxy on8.
Till now there is no any method to root Samsung galaxy on8 without pc or with pc.Our all posts are fully trusted because we published our all post after testing if they work fine. we are 100% sure you cant root your Samsung on 8 till now.so never ever try to root your devices from unauthorized websites. Fraud Websites List How To Root Samsung Galaxy On8 Without Pc? Here we are listing some fraud websites who are trying to drive traffic on their site with this fake posts.

http://www.techsliper.com/2016/10/guide-how-to-root-samsung-galaxy-on8.html http://rootkhp.pro http://rootkhp.pro/how-to-root-samsung-galaxy-on8/

Warning – all the above websites are fully fake and you cant root Samsung galaxy on8 without PC or with till now.wrong rooting method can brick your phone so don’t trust on any above websites for any phone.one wrong method can brick your phone permanently. So just wait for few days .our xda developers are working on it and as soon as they will be able to root Samsung galaxy on 8 they will update it on their official site.you can bookmark their site for instant update.otherwise we will update it on our site as soon we get any possibility to root Samsung galaxy on 8 without pc or with pc.

How to use that link 
copy one of that link and paste to your browser .


The Basics of USB Battery Charging: A Survival Guide

By:  ,muitechpro

Abstract: Arguably the most useful part of USB's power capabilities is the ability to charge batteries in portable devices, but there is more to battery charging than picking a power source, USB or otherwise. This is particularly true for Li+ batteries, where improper charging can not only shorten battery life, but also can be a safety hazard. A well-designed charger optimizes safety and the user experience. It also lowers cost by reducing customer returns and warranty repairs. Charging batteries from USB requires balancing battery "care and feeding" with the power limitations of USB as well as the size and cost barriers ever present in portable consumer device designs. This article discusses how to achieve this balance.

Table of contents
An Array of Power Sources
Detecting the Source Type
USB Connection Terminology
Port Detecting and Self-Enumerating Charger
Adding Port Detection
Other Charge Strategies
USB 3.0
"Cheating"—Noncompliant USB Charging
Wrap Up


USB has become as much a standard for connecting power to portable devices as it has for serial communication. Recently the power aspects of USB have been extended to cover battery charging as well as AC adapters and other power sources. A tangible benefit of this wide-spread use is the emergence of interchangeable plugs and adapters for charging and powering portable devices. This, in turn, allows charging from a far wider variety of sources than in the past when each device required a unique adapter.

Arguably the most useful benefit of USB's power capabilities is the ability to charge batteries in portable devices. Nonetheless, there is more to battery charging than picking a power source, USB or otherwise. This is particularly true for Li+ batteries, where improper charging can not only shorten battery life, but also become a safety hazard. A well-designed charger optimizes safety and the user experience. It also lowers cost by reducing customer returns and warranty repairs.

Charging batteries with USB requires balancing battery "care and feeding" with the power limitations of USB and the size and cost barriers ever present in portable consumer device designs. This article discusses how to achieve this balance.

An Array of Power Sources

The USB specification spans several generations of power management. The initial USB 1 and 2.0 specifications described two types of power sources (5V 500mA and 5V 100mA, respectively) for powering connected devices. These specs were not written with battery charging in mind, but intended only to power small peripherals like mice and keyboards. Of course, this did not stop designers from working out USB battery charging on their own. However, without a unified guide, interoperability between different devices and chargers was hit and miss. This limitation motivated the recent development of a supplementary USB specification, the Battery Charging Specification, Rev 1.1, 4/15/2009 (BC1.1),¹ that acknowledges charging and describes power sources that can supply up to 1.5A. Though titled "Battery Charging Specification," the document in fact contains nothing about the specifics of charging batteries. It deals only with how power should be drawn from a USB port for charging. Actual charging methods are still left up to the individual designs.

Prior to BC1.1, all USB power ports, when active (i.e., "not suspended," in USB parlance), were classified as either "Low Power" (100mA) or "High Power" (500mA). Any port could also be "suspended," which means nearly off but still able to supply 2.5mA. For the most part, ports on PCs, laptops, and powered hubs (A powered hub is a USB breakout box with its own wall wart for bus power.) are "High Power," while ports on hubs that receive no power other than what is supplied by the upstream USB host are considered "Low Power." Once plugged in, a device is allowed initially to draw up to 100mA while enumerating and negotiating its current budget with the host. Subsequently it might be allowed to raise its drain to 500mA, or it might be held at 100mA. This is detailed in the USB Serial Bus Specification Rev 2.0, section

BC1.1 goes beyond the power distribution described in USB 2.0 by defining additional power sources for charging. It defines three different source types:
  1. Standard downstream port (SDP) This is the same port defined by the USB 2.0 spec and is the typical form found in desktop and laptop computers. The maximum load current is 2.5mA when suspended, 100mA when connected and not suspended, and 500mA (max) when configured for that current. A device can recognize a SDP with hardware by detecting that the USB data lines, D+ and D-, are separately grounded through 15kΩ, but it still needs to enumerate to be USB compliant. In USB 2.0, it is not strictly legal to draw power without enumerating, although much of present-day hardware does just that, and in violation of the spec.

  2. Charging downstream port (CDP) BC1.1 defines this new, higher current USB port for PCs, laptops, and other hardware. Now the CDP can supply up to 1.5A, which is a departure from USB 2.0 because this current can be supplied before enumeration. A device plugged into a CDP can recognize it as such by means of a hardware handshake implemented by manipulating and monitoring the D+ and D- lines. (See USB Battery Charging Specification, section 3.2.3.) The hardware test takes place before turning the data lines over to the USB transceiver, thus allowing a CDP to be detected (and charging to begin) before enumeration.

  3. Dedicated charging port (DCP) BC1.1 describes power sources like wall warts and auto adapters that do not enumerate so that charging can occur with no digital communication at all. DCPs can supply up to 1.5A and are identified by a short between D+ to D-. This allows the creation of DCP "wall warts" that feature a USB mini or micro receptacle instead of a permanently attached wire with a barrel or customized connector. Such adapters allow any USB cable (with the correct plugs) to be used for charging.
Additional details on these port types are described in the USB Battery Charging Specification, Rev 1.1, 4/15/2009.

Detecting the Source Type

The trick for a device that connects to any USB receptacle and uses that power to run itself or charge a battery, is knowing how much current is appropriate to draw. Attempting to draw 1A from a source capable of supplying only 500mA would not be good. An overloaded USB port will likely shut down, blow a fuse, or trip a polyswitch. Even with resettable protection, it will often not restart until the device is unplugged and reconnected. In ports with less rigorous protection, an overloaded port can cause the entire system to reset.

A portable design has choices about how to mange port detection. It can be compliant with BC1.1, compliant only with USB 2.0, or noncompliant. If fully compliant with BC1.1, it must be able to sense and limit input current for all USB source types, including legacy USB 1 and 2.0 ports. If compliant with 2.0, it will charge from SDPs after enumeration, but may not recognize CDPs and DCPs. If it cannot recognize a CDP, it can still charge and remain compliant but only after enumeration, in the same way that it would with an SDP. Other partially compliant and noncompliant charging schemes will be discussed later.

A device can implement port detection using its own software, or can employ a charger or interface IC that detects by interacting with the USB D+ and D- data lines without relying on system resources. The design's partitioning of these roles depends on the system architecture. For example, a device that already employs a microcontroller, or a dedicated IC, to manage power may prefer to use that IC for port detection and current selection as well. Since the device already can communicate with the host over the USB connection, it can make charging choices based on the results of enumeration and configuration. These choices can be under the control of an applications processor, or a separate microcontroller that might handle power management and other system functions. The system detects the port type, enumerates, and sends appropriate commands to a charger. The charger handles the hardware and safety aspects of charging, and has built-in limits that will not allow the system to harm the battery (Figure 1).

Figure 1. Nonenumerating charger. The USB transceiver and microprocessor handle USB enumeration. The microprocessor then sets the battery charger to the correct parameters.
Figure 1. Nonenumerating charger. The USB transceiver and microprocessor handle USB enumeration. The microprocessor then sets the battery charger to the correct parameters.

A different device might not be designed to communicate with USB or does not want to devote system software to manage USB charging. It just wants to use available USB ports as a power source. This approach can be used to avoid complexity or in response to worries that a software bug might cause incorrect charging. Since the system does not enumerate, the best charging option is a self-enumerating charger IC. The charger takes care of port detection and selects the appropriate USB load current limit without requiring help from the system (Figure 2).

Figure 2. A self-enumerating charger connects directly to the USB data lines, allowing simple systems to fully utilize USB charging without a USB transceiver or microprocessor resources.<br><br>
Figure 2. A self-enumerating charger connects directly to the USB data lines, allowing simple systems to fully utilize USB charging without a USB transceiver or microprocessor resources.

USB Connection Terminology

At this point, some USB terms deserve clarification. They are "attach," "connect," "enumerate," and "configure."
    Attach The physical process of plugging in the USB cable.
    Connect When the device (that you just plugged in) connects 1.5kΩ pull-up resistance to the D+ or D- data lines.
    Enumerate The initial data exchange between the device and the host to identify device type.
    Configure Set device parameters.
In USB 2.0, it is during enumeration and configuration that the device learns how much current a USB port can source. Enumeration and configuration require a digital conversation between the device and the host. BC1.1 expands the USB spec. In addition to the USB 2.0 options, BC1.1 also allows "dumb" methods of determining port type so that, with some ports, charging can take place without enumeration.

Port Detecting and Self-Enumerating Charger

The MAX8895 determines how best to use available input power without relying on the system to evaluate the power source. The charger automatically determines the adapter type and can distinguish between:
  1. DCP: 500mA to 1.5A
  2. CDP (host or hub): to 900mA (580mA during chirp) for Hi-Speed; to 1.5A for low and fast speed
  3. Low-power SDP (host or hub): 100mA
  4. High-power SDP (host or hub): 500mA
The available current can be used by the battery or the system, or it can be split between them. A built-in suspend timer automatically triggers suspend when no bus traffic is detected for 10ms.

In addition to automatically optimizing current from USB and adapter sources, the MAX8895 also deftly handles switchover from adapter and USB power to battery power; it allows the system to use all available input power when necessary (Figure 3). This enables immediate operation with a dead or missing battery when power is applied. All power-steering MOSFETs are integrated, and no external diodes are needed. Die temperature is kept low by a thermal regulation loop that reduces charge current during temperature extremes.

Figure 3. The MAX8895 charger self-enumerates with a USB source to optimally set charge current depending on the type of connected power source. It also can maintain system operation while bringing up a deeply discharged battery.
Figure 3. The MAX8895 charger self-enumerates with a USB source to optimally set charge current depending on the type of connected power source. It also can maintain system operation while bringing up a deeply discharged battery.

Adding Port Detection

BC1.1 describes hardware detection methods to determine port type. The expectation is that integrated circuitry will be used for this, as with the MAX8895 in Figure 2, or that this circuitry will be included in the USB transceiver. Nevertheless, adding port detection, or at least some subset of it, to an existing charger may sometimes be preferred. Figure 4 shows circuitry for a rudimentary USB charger detection scheme that operates under control of the system microcontroller. This approach can detect a DCP, but cannot distinguish between an SDP and a CDP. It treats both as an SDP, which means that in some cases it can miss the opportunity to draw more charging current from a CDP. This shortcoming may be acceptable in low-budget designs.

Figure 4. A Hi-Speed USB switch implements a limited form of USB charger detection.
Figure 4. A Hi-Speed USB switch implements a limited form of USB charger detection.

The Figure 4 connection implements limited port detection as follows. When the portable device is attached to one of the three port types, VBUS powers the U1 switch and the device's microcontroller. A low logic level on U1's CB input puts it into detect mode, where the D+ line is pulled up to the system logic voltage through 10kΩ and D- is pulled to GND through 100kΩ. If a DCP is connected (which has D+ shorted to D-), then D- will go high. If either an SDP or CDP is connected, D- and the detect output will be low. If an SDP or CDP is detected, the system then drives CB low to put the switch into data mode, which connects D+ and D- to the data path for enumeration and other data transfer. There is a limitation of the above scheme: it will not recognize and, hence, not immediately charge, when attached to a CDP, although it will charge from a CDP after enumeration.

Complete port detection is shown in Figure 5. The MAX14578 contains all circuitry necessary to detect the connected device (USB cable, and USB CDP or dedicated charger) and control an external Li-ion battery charger. The device implements USB Battery Charging Rev 1.1-compliant detection logic which includes data contact detection, D+/D- short detection, and CDP identification. In addition, it includes a charge timer and weak-battery voltage monitor to support the USB BC1.1 "Dead Battery" provisions.

The MAX14578 includes a data switch that is compliant with USB Hi-Speed and original (full speed and low speed) signals. It features low on-resistance (RON), low on-resistance flatness, and very low capacitance. The CDN and CDP pins are also ESD protected up to 15kV per the Human Body Model.

Figure 5. Fully-compliant USB BC1.1 port detection can be added to a charger with the MAX14578 USB charging port detector and data-switch IC.
Figure 5. Fully-compliant USB BC1.1 port detection can be added to a charger with the MAX14578 USB charging port detector and data-switch IC.

In Figure 6 simple Li+ charging functionality is added to a USB device. The MAX8814 can be configured to charge a battery from either 100mA or 500mA USB ports. The circuit initializes at 100mA. The microprocessor then enumerates the host to determine its current capability. If the USB port is capable, the charging current is increased by turning on N1 and R1 in the current-setting network. The high-level charge is nominally set to 425mA to avoid exceeding the SDP 500mA limit after tolerances are considered. The charger also includes an autobooting circuit that provides an output signal (ABO) that notifies the system when an external power source is connected. Although USB compatible, Figure 6 does not incorporate BC1.1 so enumeration is required for charging.

Figure 6. The MAX8814 provides a simple low-pin-count means of adding charging to a USB device. Enumeration is under the control of the system which monitors and controls charge current with the ISET pin. This design is USB compatible but does not incorporate BC1.1, so enumeration is required for charging.
Figure 6. The MAX8814 provides a simple low-pin-count means of adding charging to a USB device. Enumeration is under the control of the system which monitors and controls charge current with the ISET pin. This design is USB compatible but does not incorporate BC1.1, so enumeration is required for charging.

Other Charge Strategies

The landscape for USB battery charging can be complex. Portable USB-connected devices do not follow one format and are subject to a variety of constraints—size, cost, and charge time as the most obvious. Ranking these and other more subtle issues can help you choose a USB charger design. Among these additional design considerations are:
  • Must the device be capable of full-feature operation with a dead battery once external (USB or adapter) power is applied?
  • Are separate input connections required for USB and adapter power?
  • Does the device have the computing power and firmware to negotiate charging decisions with a USB port?
  • Can charge current be momentarily lowered to reduce heat dissipation, or is a switch-mode design required?
  • What input protection measures are needed?
Multi-Input Charging
With BC1.1 it is possible for devices to charge only from USB-defined sources. Those devices are becoming more common, but still you may want to retain the option of charging with an ordinary, possibly non-USB-compliant, adapter. This is best accomplished with a dual-input charger that handles the switchover when one external power source takes over for another. In the past, power hand off was often done with either lossy OR-ing diodes or discrete MOSFET-comparator circuits that can become complex when "sneak" current paths and switch timing are considered. Fortunately, many charger ICs (Figure 7) now include power hand-off control. Integrating this function does more than simply replace external components. It also improves transition behavior during power changes because the integrated charger is aware of what the switchover circuitry is doing.

Figure 7. A dual-input charger like the MAX8844 handles charging from both USB and adapter sources. This device also protects against input overvoltages up to 28V.
Figure 7. A dual-input charger like the MAX8844 handles charging from both USB and adapter sources. This device also protects against input overvoltages up to 28V.

A common concern with chargers that accept power from multiple sources, especially ones using a common barrel connector, is the possible connection to an incorrect adapter. To anticipate this, the MAX8844 prevents charging for inputs that exceed 7.5V. It can also withstand, as well as block, inputs up to 28V. This protects the battery, the charger, and downstream circuitry against inadvertent connection to almost any known adapter type. In addition, the MAX8844 includes overvoltage-protected LDOs, biased from the USB and adapter (IN) inputs, that can supply 30mA to the system. These LDO outputs (SAFEUSB and SAFEOUT) remain on whether or not the charger is enabled. Other charger functions performed by the device are battery detection; thermal limiting that reduces charge current to maintain a low die temperature during ambient temperature extremes; and an autobooting logic output that signals the system when external power is applied.

Battery-Load Switching (Smart Power) vs. Direct Connection
In USB and adapter-powered charging applications, a key design decision is whether the charge circuitry will connect directly to the battery and the system load, or whether additional switching is needed to disconnect the battery from the system when external power is connected. The two cases are illustrated in Figure 8.

Figure 8. Illustration of direct connection charging and Maxim's Smart Power Selector™ technology.
Figure 8. Illustration of direct connection charging and Maxim's Smart Power Selector™ technology.

The direct-connection architecture is the simplest and most economical to implement. Its main drawback surfaces if the battery is deeply discharged and then external power is applied. In that case the system may not be able to boot until the battery reaches an acceptable level. In some applications it may be acceptable for a user to wait until the battery partially recharges before full functionality is restored; however, in other applications immediate operation at external power connection is a "must," regardless of the battery state. In those latter cases, Maxim's Smart Power Selector technology allows the system to use external power while the battery is in a deeply discharged state. See Figure 9.

Figure 9. A dual-input USB/adapter charger with Smart Power Selector functionality like the MAX8934 can power the system immediately when external power is applied while it also charges a dead battery.
Figure 9. A dual-input USB/adapter charger with Smart Power Selector functionality like the MAX8934 can power the system immediately when external power is applied while it also charges a dead battery.

In Figure 9 a low-resistance (40mΩ) on-chip MOSFET between the system load output (SYS) and the battery (BAT) serves multiple functions during charge and discharge operations. During charging, this Smart Power Selector switch makes the best use of limited USB or adapter power, utilizing input power not needed by the system to charge the battery. It also lets the battery serve as a storage buffer, supplying load peaks that may momentarily exceed the input current limit. During discharge, the switch provides a low-loss path from the battery to the system.

System software again handles communication with a USB host and sends commands to the charger. The MAX8394 manages the hardware aspects of charging and provides simple hooks for setting charge parameters relevant to USB and adapter charging. USB input current limits are preset to ensure that specified limits are not exceeded; a user-set current is used for adapters. The charger also supplies a complete set of status and fault signals to the system.

The MAX8934 includes the latest charging safety features, including new temperature-dependent charge protocols outlined by the Japan Electronics and Information Technology Association (JEITA) that halt or reduce charging at elevated temperatures. In addition, inputs have overvoltage protection (OVP) up to 16V and the device limits temperature rise by throttling charging current during extreme conditions.

Switch-Mode Fast Charges up to 2A with Minimal Heat
Some compact devices need high charge currents (well over 1A) but cannot tolerate the excess heat that those charge rates would generate in a linear charger. In those situations the MAX8903 (Figure 10) operates a 4MHz DC-DC converter that keeps the component footprint small while still delivering up to 2A to the battery from adapter sources. Like the MAX8934, the MAX8903 is a dual-input design that accommodates USB and adapter inputs through separate connections. Switchover between power sources is automatic, as is hand off between input power and battery power.

Figure 10. The MAX8903 switch-mode charger with Smart Power Selector capability charges at up to 2A from adapter inputs and 500mA from USB sources.
Figure 10. The MAX8903 switch-mode charger with Smart Power Selector capability charges at up to 2A from adapter inputs and 500mA from USB sources.

The MAX8903's 4MHz switching rate keeps the switch-mode converter's passive components tiny, so that a 2A charger made with this device can be smaller than a linear equivalent once the lower power loss is factored in. In fact, due to heat dissipation, most portable devices would not tolerate a 2A linear charger design under any conditions.

Overvoltage and Reverse-Polarity Protection Built In
Although the USB charging specification imposes some order on the power adapter and charger landscape, USB design remains a generally chaotic environment for portable devices, especially for those applications that opt to use the ubiquitous barrel connector for power (common on many adapter-only and dual-input devices). It is far too easy for consumers to connect a "found" adapter that may have the wrong output voltage or even the wrong polarity. By integrating positive and negative 22V protection at the charger power input, the MAX8900 adds piece of mind to these designs without requiring external protection devices or MOSFET switches (Figure 11).

Figure 11. Direct-connect switch-mode charger with ±22V overvoltage and reverse-polarity protection.
Figure 11. Direct-connect switch-mode charger with ±22V overvoltage and reverse-polarity protection.

The MAX8900 is a direct-connect style charger with the system typically connected to the battery. Its 3.25MHz switch-mode design keeps components small while charging at up to 1.2A with minimal heat dissipation. In addition to bipolar input protection, battery safety is enhanced by adjusting charge parameters as a function of temperature in accordance with JEITA guidelines.

NiMH Charging from USB

Figure 12. A 1-cell NiMH USB-powered switch-mode charger.
Figure 12. A 1-cell NiMH USB-powered switch-mode charger.

Even though it seems that Li+ cells have taken over the portable world, NiMH cells have not been standing still. Surprisingly, NiMH energy per volume is only about 15% lower than Li+, although energy per weight is still quite a bit less. The biggest weakness of NiMH is its high self-discharge, which has largely been solved by hybrid NiMH cells, such as the SANYO® Eneloop® cell, that retain as much as 85% of their charge after one year. The attractions of NiMH cells are cost, safety, and easy user replacement, at least when standard cells are employed.

Figure 12 shows a small portable device that is powered from one AA NiMH cell and charges from USB. The DS2710 charger switches at approximately 150kHz and charges the battery at 1.1A (about 0.5°C for a typical AA NiMH cell). The circuit gets more current into the battery (1.1A) than is gets from the USB port (500mA) because a step-down ratio converts 5V at 500mA, to 1.5V at 1.1A at the battery. It should be noted that charging can occur only with 500mA or greater ports, since proper charge termination cannot be assured at low charge rates. Consequently, charging should not be activated when enumeration determines than only 100mA is available. The system deactivates the charger by turning off Q2 to float the timer resistor at TMR.

Another particularly useful feature of this charger is that it senses battery impedance to determine if an alkaline cell or a faulty battery is inserted. If that occurs, charging suspends. This allows end users to plug in an alkaline battery in an emergency and not worry about inadvertent charging.

USB 3.0

The USB 3.0 spec brings still higher data rates to USB. The power aspects of the spec are similar to USB 2.0 except that a "unit load" is raised from 100mA to 150mA and a high-power port has to supply six, rather than five, unit loads. This means that a low-power USB 3.0 port can supply 150mA, and a high-power USB 3.0 port can supply 900mA.

"Cheating"—Noncompliant USB Charging

As with any standard that is co-opted for purposes not originally intended, manufacturers sometimes ignored portions of the USB 2.0 requirements in order to provide at least a limited form of charging. One such noncompliant scheme used by a major manufacturer was to draw no more than 100mA under any circumstances, so that neither high- nor low-power hubs were overloaded. The downside of limiting current to this level was that battery charge time was long, but if the device spent a large part of the day docked to a USB port that might still be adequate. Besides a long charge time, there was another limitation to this approach: if the system had a dead battery, full functionality would be delayed until the battery reached a sufficient charge level.

Another aspect of noncompliant charging relates to the treatment of USB suspend. USB 2.0 stipulates that all devices must suspend (draw less than 2.5mA) after a set period of bus inactivity. Since charging was never included when this was written, there was no consideration for a device continuing to charge a battery while off, but still attached. However, since most USB hosts do not actually turn off power, this violation of the specification rarely prevented charging.

A bolder noncompliant scheme assumes that 500mA will be available and instructs users to plug only into powered ports and hubs that are capable of 500mA. Again, since most USB ports do not disconnect power, this approach can work in most cases. When such a device is plugged into a port that cannot support 500mA, the port is supposed to shut down. However, the overload behavior of a USB port is not always well defined and can lead to system reset or damage. Fortunately, this level of desperation is no longer required since battery charging is now an active part of the USB specification.

Wrap Up

Charging from USB can take many forms, governed by the unique requirements of each USB device. The USB Battery Charging Specification. Rev 1.1 finally adds much needed uniformity to what was previously an ad hoc charging activity. The adoption of BC1.1 should lead to reduced cost for manufacturers and consumers, and greater interoperability as standard adapters emerge. Nevertheless, the USB guidelines only cover how power is to be taken from the port; they still leave power-management architectures and charging specifics open to interpretation. That is where Maxim's broad spectrum of charging devices becomes important, as they can help speed the design of safe and reliable battery chargers for nearly any USB-connected portable .


formatable or not working and cant be formated by general methods

Hy friends here i will describe about how to format your memorycard completely using "diskpart" kind of windows utility software in windows environment

First of all why a memory card gets corrupted and stop working, its may be due to having bad sector files, or sometimes due to uncomplete formating means not formated properly.

If this happens the general idea comes to everyone is
Memory card can no longer be used
,the same thing i have experienced many times at that time i was totally out of my mind what to do, then one of my friend sugessted me this process and it really worked, now i am going to share it with all of you ,so it can be of help
Now lets get straight to topic:

You will gonna need an windows operating system installed on pc, or laptop
now turn it on, and click on the start menu then type cmd in the run dialog box and click ok as shown below

then the command prompt will open in the command window type diskpartas follows
then press enter key

From here the real work starts,you have to type list diskas follows
then press enter key
you can type list disk it will do, the reason is to list out all the disks those are curently attached to your pc including the hard disk and removable disk

here your disk will be also listed ,search for your disk, to do this search under free or size

if your disk is of 8GB it wil be listed as 8x1024=8192MB and like wise

now type
select disk 1 here the number one refers to your disk number you have to type your volume no. means if your volume is listed as Disk 2 then type select disk 2 and likewise now press enter key

The screen will look like the picture

Type clean,press enter key ,it is used for cleaning or erasing the data from memorycard

If it suceeded in cleaning then a message disk part succeeded in cleaning same as the above pic will show on screen

Now type create partition primary press enter key
it means your memorycard's memory partition will become a primary partition

After it completed now the turn is to format your memorycard
For this you have to typeformat fs=fat32 here format fs= is syntax , and the fat32 is the memory type , if you want to format as ntfs then type format fs=ntfs after typing press enter key
Now the last and final step

Typeassign,used for assigning a letter to disk ,or creating mounting point
when it shows successfully asiigned drive letter or mount point, typeexit or just click on close button

Congrats just after a few seconds a window will pop up like when you attach a new disk or pendrive have fun with your memory card

Here my advice to you is Never remove your the device you want to format during this process
You can also use this process to create a bootable device ,means to create a operating system installation disk,on removable devices like pendrive

How to: Make your own USB OTG cable for an Android smartphone

Some high-end Android phones and most of today’s Android tablets support USB OTG (On-The-Go). This enables users to connect standard USB input devices such as keyboards and mice, or even extend storage using a regular USB pen drive. However, only a few Android tablets are equipped with a USB host port (Type A Female connector), while no mobile phone is. Some mobile phone manufacturers ship USB host ports with their handsets while others have them as optional accessories, usually at a premium price.
In order to connect an Android phone to a standard USB device, you need to use a micro (or mini) USB to USB Type A Female convertor, but this should also be an OTG cable. A mini USB OTG cable is available in the market and can cost you around Rs.150 – Rs.300, but finding vendors who actually sell it is not easy. The ones that are available are not guaranteed to work. The case of the micro USB OTG cables is also similar.
USB connector types
USB connector types
In this workshop, we show you how you can build yourself an OTG cable (be it micro or mini) at almost no cost. Do note that the procedure mentioned here will involve hacking into your existing cable, and even a small blunder can potentially damage your cable or the device you use it with. Proceed with extreme caution as we take no responsibility for any damages to your device. Do this at your own risk. Furthermore, do take note of your Android specs and check carefully to see if it has OTG capabilities before trying out this workshop. Phones don’t need to be rooted as the stock ROM usually supports OTG in compatible handsets. Those who have installed third-party developer ROMs should check with the developers if the OTG feature is enabled in the kernel.
Slicing the connector sleeve
Slicing the connector sleeve
Since all phones usually ship with cables, we suggest you opt for a second one from the market to create the OTG cable. For those who are not able to find a similar cable, this workshop will also show you how you can use the same cable for regular and OTG modes. In the following procedure, we'll be using a micro USB cable that we’ll convert to be used with USB OTG.
  • A standard mini or micro USB cable
  • Some small, thin wires
  • A sharp knife
  • Soldering iron and solder wire
  • Wire cutter
  • Hot glue or any quick glue
Firstly, we need to slice open the micro USB connector end very carefully using a knife. The idea here is to cut the outer sleeve (length-wise) into two halves to reveal the connector inside. Be careful not to destroy the outer sleeve as we shall be glueing it back on after the work is done.
A miniature switch
A miniature switch
After the sleeve is taken apart, some of you might find a whitish plastic mould covering the connector’s leads. This is for strengthening the cable to connector contacts, and its use depends from manufacturer to manufacturer. Those who have this mould will also have to cut through it to reveal the connector leads. On revealing the connector leads, you will find that it has five leads and not four. The usual four are power, data, data and ground, while the non-connected lead is sense. This lead needs to be grounded before connecting the cable for the phone to switch to OTG mode and sense a USB device connected to the interface.
The difference - circuit
The difference – circuit
Given above is the pin-out diagram for the micro and mini USB connector.
Pin 1: VCC
Pin 2: data
Pin 3: data
Pin 4 Not connected / unused
Pin 5: ground
In order to get the phone to go into OTG mode, we need to short Pins 4 and 5. You can either choose to short them permanently by soldering them together or soldering two wires to each of the pins and leading those outwards from the connector, which can then be soldered to a small switch. Using the switch, we can switch the cable between normal and OTG whenever needed. If you choose to short it permanently, you will have to cut off the connector at the other end (The Type A Male USB connector) and solder a Type B Female connector to accommodate a USB device. You can also choose to have a male to female USB convertor at that end. Here's what we did:
The connector and the sleeve
The connector and the sleeve
We chose to connect a small switch to the leads at Pin 4 and Pin 5 and glue the switch to the wire itself. This way, we could use the cable for both regular and OTG purposes. Next, we glued the connector sleeves back carefully using hot glue. Now the other end of the cable, which has a male USB connector, needed to be converted into a female. For this, we opted for the scrapped USB rear panel connector of a desktop PC. We soldered the wires of the USB connector to create a USB female-to-female convertor. Once done, we now have an OTG cable ready for use. Just to ensure we do not end up frying our phone, we used a multimeter to double-check any cable shortings during the soldering. Lastly, we connected the OTG cable to our Android (the Sony Ericsson Live with Walkman) and used a USB mouse with it. If your cable worked for you and your phone is compatible with OTG features, you can also connect a USB hub to the OTG cable and use a USB keyboard, mouse and pen drive together on the same Android device.
Micro USB Pin points
Micro USB Pin points
By following this workshop you can now conveniently use a pointing device to control your apps and games, use a keyboard to type e-mails and messages or use a pen drive to store or access media or large files. If you are lucky enough to find a micro USB connector and a Type A Female USB connector at an electronics store though, you can make your own OTG cable for under Rs.100
by muitechpro


IMEI Changer Tool

IMEI Changer tool is a new software that can help you to find a way how to change imei number on any device which have this registration number from his factory. This software application was been made from our software professionals in cell phone using technology. On the market today you can find a lot of device’s on which you must put new IMEI number that will get you free from all restrictions.
IMEI Changing Tool

Change IMEI Benefits

Using of this service offer you a lot benefits. Thanks to this innovation software you can use any stolen or lost cell phone (or any other device which use this number) without any problems. The second good information is that if you use the imei changer app you can practically remove all carrier’s restrictions that you get when you buy your device at the first place.
Well the second opportunity is to unlock a phone device and to use it on any carrier and any carrier plan that you want. If you have this restrictions you can’t use your mobile phone device on some other sim card from some other carrier. Once you complete the changing imei number procedure your device will start work on any sim card from any carrier worldwide without asking unlock code or some other problems. So now you have big chance to remove all problems from the past on your device.

To Use IMEI Changer You Must Know IMEI Number

If you want to use the imei number changer you must know this number that your device have it. The easiest way to find your imei (international mobile station equipment identity) number is to wrote *#06# and you will get a new window on your device’s screen in which you will see your imei number. Wrote this number to have it once you will start whit the new imei number changing process. If you have the original box in which you buy your device you can find it this number on the back side on this box. In the worst case you can contact your carrier.
They will send you information about your imei number. But you must have this number for sure if you plan to use our software service. Pay attention to write this number correctly. If you make mistake your old imei number will stay on your device. If you make mistake tree times in a row then your old imei number will stay permanent. So please don’t start whit the changing imei process if you don’t have information about your right imei number.Find IMEI Number

IMEI Changer Tool Apk

Our IMEI changer tool  is an online calculator and generator at the same time. The software is capable to calculate your old imei number and to generate your new number. This service can make calculation for all places on which your old imei number is registered in the past and will make changing calculation to remove the old and wrote the new one. This is really important for your device. The changing database process will save you from some possible problems in the future. So don’t worry about having inconvenience from any type when you will use any service on your imei changed device.
The tool have the power to read your device’s information directly whit support on your imei number. To use this software solution service you must connect your device on which you want to change imei number via usb cable whit your computer on which you will use our online imei changer application. Bellow in this post you will be going in this process in a step by step guide. The last and the best information about our software work is that you will complete this process for free. Yes now there is no need for you to pay for this service on some another place when you have free solution available.

IMEI Changer Supported Brands

The IMEI apk from this page you can use it on any device from the list bellow:
  • iPhone
  • iPad
  • Apple MAC
  • Samsung
  • Huawei
  • LG
  • Sony
  • Nokia
  • Microsoft
  • HTC
  • ZTE
  • Blackberry
  • Kyocera
  • Lenovo
  • Alcatel
  • Motorola
  • ASUS
  • Xiaomi
  • Micromax
  • Acer
  • Toshiba
IMEI Changer
The imei changing tool successfully will change the imie number no meter from which carrier company your device is.

How To Change IMEI Number

To change the imei number successfully you just need your right imei number and our online imei changer code generator tool available on our website for free. Once you know your imei just follow the guide step by step bellow:
  1. Get the IMEI changer on your computer (the tool is compatible whit any windows, MAC or Linux operative system by click on the change button bellow:Online IMEI Changer
  2. So connect your device on which you need to make this process whit your PC via usb cable,
  3. Then open the software whit left double click,
  4. Also select your device’s brand and model,
  5. Then fill in your imei number that you must change,
  6. Also click on the generate button,
  7. Then read our terms of service and click on the START button,
  8. Wait about 30-40 seconds and pass the human verification procedure (please use your real information in this procedure),
  9. Once you will pass the verification process you will get your new imei number in a new window,
  10. Then disconnect your device from your computer and type *#06# to check your new imei number that is now installed directly on your device.
  11. Finally congratulation you have successfully complete the changing imei number process!IMEI Changer Tool

How To Change IMEI Number Successfully

Now when you have your new imei number you can use it no meter if you have lost or stolen device in your property. We give you advice to check your mobile phone carrier plan and to change it if you have a better option that is more cheaper for you.
So this change carrier cell phone plan will help you to save some money on your budget. You also know that the unlocked cell phones have much expensive price if you want to sell this device or devices. So this means that our IMEI Changer tool can grow your device’s price on the market whit changing imei number process. Feel free to ask for help from our online support team by mail or in comment bellow.

SPD imei changer tool


 Fix for Error This copy of Windows is not Genuine

This method will work for 32 bit and 64-bit versions of Windows 7. You must follow below three steps to eliminate the error. You don’t see the error after the second step even then you must follow the third step. Otherwise, you may get this error back once again.

Step 1 Uninstall Update KB971033

You are getting the error “this copy of windows is not genuine,” that means your windows has an updated file which can detect your Windows OS. So before going into the actual procedure, You must uninstall the update which was detecting your windows. Remember, if you see this mentioned update, then only you need to uninstall. If you don’t see this update, you can skip this step. Follow the below steps to uninstall Windows update.
  • Open control panel.
  • Go to windows update section.
  • Click on view installed updates.
  • After loading all installed updates, check for update “KB971033” and uninstall.
  • Restart your PC. If you don’t see the mentioned update, you need not uninstall any update. You can leave this step and proceed to the second step.
 Exclusive Gift: Want to read this article offline? Click Here to Download Our Free EBook Which gives you Simple fix  for Windows (7 & XP) Not genuine Errors.

Step 2: Use SLMGR -REARM command

Now Let’s see the actual procedure to fix Windows not genuine error.
1. Go to Start Button for Start Menu.
2.You need to type cmd in the search field.
3.You will see command prompt option. Right click Command prompt. Select Run as Administrator. It is must run the command prompt with administrator privileges otherwise command will not work.
4.Type SLMGR -REARM (SLMGR is a tool which manages Windows software license. REARM is a command which resets license status of the machine.) and press enter.
This copy of windows is not genuine
5. You will see a window, Click OK.
6. Just Restart your PC. Now you will never receive the error message. If this command did not work for you, you need to try SLMGR /REARM.
SLMGR -REARM must work for Windows 32 bit version. It may work for Windows 64 bit version. If it did not work for Windows 64 bit version, then only you have to try SLMGR /REARM.
In most cases above command works. Sometimes, there is a chance that you may get any one of the below two errors. I have given solutions for those errors.
Error  1: – If you get “Error 0xc004d307: The maximum allowed the number of rearms has been exceeded” after entering the command. Read my article How to Fix Error oXcoo4d307 to maximize allowed re-arms.
Error 2: –  If you get the error “slmgr is not recognized as an internal or external command” after entering the command. Read my article How to fix SLMGR is not recognized as an internal or external command.

Step 3: Turn off Updates

You are not using original OS, so you are not authorized to get updates. And you must turn off updates. Otherwise, you will get the same error one more time. If you don’t turn off updates, you OS will get updated. Any one of future updates may detect your OS Genuity. So there is a chance that you will get the error one more time. Just follow below procedure to turnoff turn off updates.
  • Go to Control Panel.
  • Click Windows Update.
  • Click Install updates automatically(Recommended).
  • You must select Never Check for Updates(Not recommended).
If you get blank screen even after following above steps, just change the background in system properties.     
If you get the error even after following above procedure, you need to reinstall Windows 7 from any CD/DVD and follow above procedure carefully. Then you will never get This copy of Windows is not genuine error.

Final Word

When you follow above methods properly, you will not see any error in the future. You can use your OS forever but without updates.
Remember, Always hackers attack older versions of OS and software on your computer to place malware and to hack your details. I always recommend you to use the latest versions of OS and any software. Then only your computer will be free from virus and your details will be safe. It is best to buy Genuine Windows OS from Microsoft Store.