By: Sukanta bera
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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.
As our lives become more and more automated, we tend to rely on computers and unseen algorithms to “protect” us from unapproved experiences. In order to illustrate this concept, and hopefully introduce serendipitous events to our digital lives, David Columbini has come up with an installation that feeds information to users via a web app, available only when it’s on display.
Instead of implementing a carefully designed algorithm, what users experience is based on constantly evolving local weather data sensed by a physical machine equipped with an Arduino Mega, a Raspberry Pi, various sensors, and some other components.
“The Weather Followers” is comprised of four different instruments: a wind-driven messaging app, a pollution-distorted selfie tool, a music player based on the rhythm of rain, and even a device that erases your feed depending on the sun’s intensity!
The installation is comprised of two elements, the four weather instruments and the webapp. Users are invited to connect to the weather machine through the webapp and choosing between one of the four weather instruments: Windy encounters (when your digital social life follows the wind), Polluted Selfie (when your digital individual life follows the pollution), Drizzly Rhythms (when your digital audio life follows the rain) and finally Sun(e)rase (when your digital overwhelming life follows the sun).