Many USB powered consumer electronic devices have built in Qualcomm QC (Quick Charge) solution for rapid charging at different voltages rather than the usual 5.0 volts. This enables the opportunity to use QC compatible Power Banks for projects require more power or higher voltages like 9/12 volts.

        The purpose of this project is to develop a device that can hack the QC protocol and allow hobbyists, developer, engineers to use their QC supported charger / power banks as a variable voltage source / power supply. This board is built around the most cheapest microcontroller N76E003 – a 1T-8051 based series MCU, offers 18 KB Flash ROM, configurable Data Flash and 1 KB SRAM . In a TSSOP20 package from Nuvoton. It reduces the board cost drastically.

The output voltage can be changed with a single press of the button.and the output voltage will be indicated by an onboard RGB led ,Green-5v,Blue - 9v and Red - 12v. Output voltage can be saved by long pressing the button which will indicate the value is saved by flashing the rgb pattern. Once the value is saved the default output on the next powerup will be the saved value.The QC negotiation at the start up will be also indicated by lashing rgb pattern.

The board have both microusb as well as USB type C port. Which will enable the user to use either microusb or USB type C cable.

QC power source devices, there is an internal boost converter which can pump up the voltage depending on the power receiving device's request . QC 2.0/ QC 3.0 utilizes D+ and D- of USB for negotiation. We can change the VBUS voltage by manipulating voltage signals on D+ and D- lines. The table below explaining what signal pair on D+/D- from PD will make the QC to deliver what voltage output:

The image below shows how different voltage levels are generated using two gpio pins.