Posts with «power supply» label

Look what came out of my USB charger !

Quick Charge, Qualcomm’s power delivery over USB technology, was introduced in 2013 and has evolved over several versions offering increasing levels of power transfer. The current version — QCv3.0 — offers 18 W power at voltage levels between 3.6 V to 20 V.  Moreover, connected devices can negotiate and request any voltage between these two limits in 200 mV steps. After some tinkering, [Vincent Deconinck] succeeded in turning a Quick Charge 3.0 charger into a variable voltage power supply.

His blog post is a great introduction and walk through of the Quick Charge ecosystem. [Vincent] was motivated after reading about [Septillion] and [Hugatry]’s work on coaxing a QCv2.0 charger into a variable voltage source which could output either 5 V, 9 V or 12 V. He built upon their work and added QCv3.0 features to create a new QC3Control library.

To come to grips with what happens under the hood, he first obtained several QC2 and QC3 chargers, hooked them up to an Arduino, and ran the QC2Control library to see how they respond. There were some unexpected results; every time a 5 V handshake request was exchanged during QC mode, the chargers reset, their outputs dropped to 0 V and then settled back to a fixed 5 V output. After that, a fresh handshake was needed to revert to QC mode. Digging deeper, he learned that the Quick Charge system relies on specific control voltages being detected on the D+ and D- terminals of the USB port to determine mode and output voltage. These control voltages are generated using resistor networks connected to the microcontroller GPIO pins. After building a fresh resistor network designed to more closely produce the recommended control voltages, and then optimizing it further to use just two micro-controller pins, he was able to get it to work as expected. Armed with all of this information, he then proceeded to design the QC3Control library, available for download on GitHub.

Thanks to his new library and a dual output QC3 charger, he was able to generate the Jolly Wrencher on his Rigol, by getting the Arduino to quickly make voltage change requests.


Filed under: Arduino Hacks, hardware

USB Charger Fooled into Variable Voltage Source

USB chargers are everywhere and it is the responsibility of every hacker to use this commonly available device to its peak potential. [Septillion] and [Hugatry] have come up with a hack to manipulate a USB charger into becoming a variable voltage source. Their project QC2Control works with chargers that employ Quick Charge 2.0 technology which includes wall warts as well as power banks.

Qualcomm’s Quick Charge is designed to deliver up to 24 watts over a micro USB connector so as to reduce the charging time of compatible devices. It requires both the charger as well as the end device to have compatible power management chips so that they may negotiate voltage limiting cycles.

In their project, [Septillion] and [Hugatry] use a 3.3 V Arduino Pro Mini to talk to the charger in question through a small circuit consisting of a few resistors and diodes. The QC2.0 device outputs voltages of 5 V, 9 V and 12 V when it sees predefined voltage levels transmitted over the D+ and D- lines, set by Arduino and voltage dividers. The code provides function calls to simplify the control of the power supply. The video below shows the hack in action.

Quick Charge has been around for a while and you can dig into the details of the inner workings as well as the design of a compatible power supply from reference designs for the TPS61088 (PDF). The patent (PDF) for the Quick Charge technology has a lot more detail for the curious.

Similar techniques have been used in the past and will prove useful for someone looking for a configurable power supply on the move. This is one for the MacGyver fans.


Filed under: Arduino Hacks, hardware

Arduino motor control problems!

 

Update 06/11/2016

Hey guys,

I sort of got the motor working. Adding a small resistance(about 2-3ohms) in series with the motor seemed to stop the Atmega reseting whenever Pin 3 was pulled HIGH (still don't know for sure what was causing this!). I'll still continue t troubleshoot this problem and completely figure out what exaclty was causing the Atmega to reset, since the resistor is not a permanent solution (wasteful energy loss). I'm really grateful for the huge amount of help from here guys!! Thanks alot! :)

Cheers!

read more

Let's Make Robots 26 Oct 12:06
arduino  avr  motor  noise  power supply  

Arduino motor control problems!

 

Update 06/11/2016

Hey guys,

I sort of got the motor working. Adding a small resistance(about 2-3ohms) in series with the motor seemed to stop the Atmega reseting whenever Pin 3 was pulled HIGH (still don't know for sure what was causing this!). I'll still continue t troubleshoot this problem and completely figure out what exaclty was causing the Atmega to reset, since the resistor is not a permanent solution (wasteful energy loss). I'm really grateful for the huge amount of help from here guys!! Thanks alot! :)

Cheers!

read more

Let's Make Robots 26 Oct 12:06
arduino  avr  motor  noise  power supply  

Arduino motor control problems!

 

Update 06/11/2016

Hey guys,

I sort of got the motor working. Adding a small resistance(about 2-3ohms) in series with the motor seemed to stop the Atmega reseting whenever Pin 3 was pulled HIGH (still don't know for sure what was causing this!). I'll still continue t troubleshoot this problem and completely figure out what exaclty was causing the Atmega to reset, since the resistor is not a permanent solution (wasteful energy loss). I'm really grateful for the huge amount of help from here guys!! Thanks alot! :)

Cheers!

read more

Let's Make Robots 26 Oct 12:06
arduino  avr  motor  noise  power supply  

Arduino motor control problems!

Hey guys,

I'm having trouble regarding motor control in a project I'm working on.

It uses an ATMega328 DIP package on a PCB. The motors I'm using are small coreless motors and I'm trying to control them using Si2302ds N-MOS FETs. For the power supply I'm using a 3.7V(4.2V on full charge) Lipo. I've tested this setup on a promini before and the motors turned on and off just fine.

read more

Let's Make Robots 26 Oct 12:06
arduino  avr  motor  noise  power supply  

Bench power supply resetting thingy

As is common among some hackers, [Henry] re-purposed an ATX power supply unit to function as a bench power supply for testing circuits on a breadboard (much like this fancy example).

However, safety mechanisms on some modern PC PSUs do not automatically reset after over-current protection has kicked in, which soon became annoying for [Henry]. In order to make his power supply more hacker-friendly, he wired up and programmed an ATtiny85V, using some Arduino libraries, to do that for him. This simple project is a great example of using a hack to improve a pre-existing hack.


Filed under: ATtiny hacks, pcs hacks

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Let's Make Robots 01 Jan 00:00