a GND pin can be used for Saber tooth motor controller another 6pins together D9 D10 D8 with VCC

and GND used for DC Motor Driver 2×15A - Lite D2 –D6 are used for the encoders.

Nano slots

There are 2 Nano slots on the GMR. For general mobile robot, this two micro controllers can help

you to solve the motor control and driver some special sensors. And they all have connected with

the main micro controller Mega ADK or Mega 2560. The communication way is the I2C.

Mega ADK/2560

The main controller of this GMR board. Because of the high performance of the Arduino Mega

ADK/2560. For the GMR, 8 I/O and 8 analog pins can be used. 3 groups of I2C pins can

communicated with other controllers and 2 groups of RS485 belongs to another nano controller。

SD card slot