Is your QT Py all alone, lacking a friend to travel the wide world with? When you were a kid you may have learned about the “buddy” system, well this product is kinda like that! A board that will watch your QT Py’s back and gives it the power and support to wander out past your USB port.
This little lipo charger is designed to fit onto the back of any QT Py board and make it easy for portable powering. Simply plug any standard 3.7V/4.2V lithium polymer or lithium-ion rechargeable battery into the JST plug on the end. When powered by the USB port on the QT Py, the charger kicks in and will charge up the battery at 200mA max rate. You’ll see the yellow LED light up when that happens.
When the USB is removed, the battery will reverse charge into the 5V port via a Schottky diode. You can turn it on or off with the built-in slide switch as well.
A simple voltage divider on the cathode side of the diode and connected to pin A2 will let your firmware detect basic modes: if the voltage is over 4.3V, it is probably plugged into USB. If the voltage is 4.2V or below its probably running on the Lipoly battery and you can roughly determine the battery state.
Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.