According to this post in broken english by famous user @sinovoip Banana Pi M2+ chose a partially incompatible pin mapping for the 40 pin GPIO header. They seem to use Pin# | GPIO | Function | Pin# | GPIO | Function --- | --- | --- | --- | --- | --- 01 | --- | SYS_3.3V | 02 | --- | VCC_5V 03 | A-12 | TWI0_SDA | 04 | --- | VCC_5V 05 | A-11 | TWI0_SCK | 06 | --- | GND 07 | A-06 | PWM1 | 08 | A-13 | UART3_TX/SPI1_CS 09 | --- | GN