On the ☒CHIP, the xBUS connector has 10 pins (5 on either side). Of these 10 pins, 4 pins are used for power and 6 pins are used for data transfer.
4 power pins for:
- A ground pin GND (0 V)
- Provides 3.3 V
- V source is a battery or power source (which can be used to supply raw power)
- V in is a battery input pin which has not been used but one possibility would be to use it for solar power etc.
6 data pins for:
- 2 pins used for I2C: one is for SDA and one is for SCL
- 2 pins used for serial (aka UART): one is for TX and one is for RX
- 2 pins used for programming: one pin is for programming other core modules and one pins is a reset pin.
- link to i2c page
- link to serial page