My Robot is controlled by the Arduino MEGA2560.
Quite all the features of the MEGA2560 are used: 3 Serial interfaces, I2C, SPI, PWM, ADC and 2 interrupts. This is why I have chosen the MEGA2560 which offers such large number of interfaces. But note that MEGA2560 is a little bit limited regarding the interrupts because 4 of the 6 interrupts are not available if I2C and Serial2 are used.
This is a companion discussion topic for the original entry at https://community.robotshop.com/index.php/robots/show/robot-arduino-esp8266-connected-to-raspberry-pi