Wrong wiring TX and RX

[sarsi]

Recently, I tried to connect the mini board to a Raspberry Pi via 3.3, GND, Rx and Tx but was not successful, however, I was able to do so with an ESP32 Node MCU board. On further troubleshooting, I went on to do connectivity check between the board pin and the ESP32 wroom-32 module pins, I was surprised to discover that the TX pin(UART0:TXD) on the board was wired to the RX(34) on the ESP32 module and the RX pin(UART0:RXD) was wired to TX(35) on the ESP32 module. So, I tried connecting the TX (i.e. wrongly connected to ESP 32 module RX pin 34) to the Pi TXD and RX (i.e. that was connected to ESP32 TX pin 35) to the Pi RXD, everything just worked. So just incase anybody is trying to connect this board to Raspberry Pi do note the wrong wiring.

My main reason for connecting the board to the Pi via gpio pins is so that I can have it piggy back on the Pi board via a prototype shield instead of having it stick out of a Pi USB port. When connecting via 3.3v, GND, Rx and Tx, the device used is /dev/ttyAMA0 instead of /dev/ttyUSB0.