Datasheet

An introduction to the Gertbot
Posted by stuartChilds on Mon, Jul 06 2015
A look at the hardware capabilities and software support for the Raspberry Pi robotics
board.
The Raspberry Pi is a popular single-board computer with plenty of GPIO (general purpose
input output) pins making it ideal as a development platform for physical computing projects.
These are fine for low power applications, with most pins at 3.3V able to provide a maximum
of 50mA draw. For applications that require more power, such as driving motors, additional
hardware is needed.
Enter the Gertbot: an add-on module for the Raspberry Pi that plugs directly on to the GPIO
pins. It is aimed primarily at driving motors, with four H-bridges on-board it can drive up to
four DC motors with up to 30V at 2.5A or two stepper motors. There is the option of
cascading up to four Gertbots per Pi, giving more outputs as required.
Additional GPIO includes two DACs, four ADCs and two open drain outputs. This means that,
for example you can connect analogue devices like potentiometers, force sensitive resistors
and moving coil meters to your Pi too.
Also on-board is a 64MHz Cortex-M3 ARM microcontroller that comes pre-programmed with
it's own firmware that takes care of the signal timing and PWM generation, meaning the Pi
does not have to be running a specialised real-time kernel or operating system.
For peace of mind there is thermal and short-circuit protection, as well as pre-configured
safeguards such as an emergency stop and system halt upon motor failure, that run on the
ARM microcontroller and can be called with high-level commands from the Pi.