Arduino Boards For Monitoring PSU PMbus Data. Base on the Mega128L Nano Board & ESP8266 Board. Arduino HW&SW Compatible. Boards HW Libraries Mega128/2561; Mega644A; ESP8266 Mega Nano Board With Serial: Mega Nano Board with Serial & OLED: ESP8266 Board with Serial & MQTT(IoT): ESP8266 HEKR V1.1 Board & Schematic: