I don't work on this often, so when I do, I feel like I'm having to go back and figure things out. These notes will hopefully save me some time.
PIO platform.ini (first 4 lines)
Digital Pins: just the digit (0, 1, 2,... -- number matches IO)
Analog Pin: A0, A1, A2, A3, A4, A5 (number matches IO)
static const uint8_t SDA = 8; //IO8
static const uint8_t SCL = 10; // IO10
Lolin I2C Port and Qwiic / StemmaQT (Not Compatible!) - both use 4 Pin SH1.0 connectors
Lolin: VCC SCL SDA GND
Qwiic: Black Red Blue Yellow
|Lolin ESP32-C3 Pico I2C Connector|
Make C3 boards into Device Firmware Upgrade (DFU) mode.
- Hold on Button 9
- Press Button Reset
- Release Button 9 when you hear the prompt tone on USB reconnection
Make sure to check polarity of the battery before plugging it in! For my battery the JST polarity connections were backwards.
https://learn.adafruit.com/assets/113383 (stemmaQT/qwiic connector)