Gertbot Rev 2.3-September-2014 Gertbot Rev 2.3, 8 September2014 The Gertbot is a motor/power controller board for the Raspberry-Pi. The strength of the board is that it has its own CPU which frees up the Raspberry-Pi from a lot of intense computations and will take care of all the real time requirements. All you have to do is give it high level commands. Like: Board 2, Motor 1, take 2432 steps at 67 Hz. Even giving those commands is done for you using the free GUI which comes with it Hardware features: Four H-bridges 8V-30V, 2.5A. Bridges can be re-configured for 2x 5A or 1x 10A. Two open drain outputs 30V, 3A. Power full 64MHZ ARM Cortex-M3 processor RS232 connects direct to the Raspberry-Pi or other serial interface. Cascade port to control up to four boards at a time. 20-pin connector programmable for: o Automatic motor end-stop o Four 12-Bit ADC ports o Two 12-bit DAC ports o 8-16 general purpose I/O Software controllable features: 1 Brushed motors: o Control direction o Speed control PWM 10Hz-10KHz, 0-100%. o Soft start 0.1sec .. 5 seconds prevents in-rush current o Stop on switch hit. Stepper motors: o Take X-steps in either direction o Step speed 0.06 Hz .. 5KHz. o Stop on switch hit. Digital Command Control (model train control): o Can send any DCC command 3..6 bytes o Programmable pre-amble length and repeat count Short-circuit or high temperature error detection On error, keep running, stop motor, stop board or stop all boards I/O pins programmable functions Emergency stop, halts whole system. The board comes with drivers, example code and a GUI all complete with source code. Depending how fast you can screw the wires down, you can have your motors running in a few minutes 1 I used the term brushed motor to indicate the standard DC brushed motors. You find those in most toys. 1 Copyright 2014 Fen Logic Ltd. The copyright is on the manual as well as the instruction set Gertbot Rev 2.3-September-2014 The board can also be used to drive other power electronics like LEDS, relays etc. Using a 30V supply and 2mA LEDS you can drive three sets, each of ~12500 RGB LEDS, using the boards PWM feature to control the colour. READ THE MANUAL The most difficult part of controlling motors has been taken care of by the software running on the Gertbot. Instead of directly having to manipulate the motors, you send high-level commands to the Gertbot which will execute them. But this does mean that you have to learn what those commands are. Therefore you should read the manual. Quick start: For those of you who want to start quickly: there is a Gertbot GUI which you can use to control every feature of the Gertbot. There is a separate Gertbot GUI manual which guides you through the controls but it refers to this manual to explain the details of operation. Advanced: The Gertbot Advanced guide helps you with cascading boards, operate bridges in parallel to double or quadruple the maximum current. It also tells you how to upload new software versions or how erase the current program and put your own software on the board. 2 Copyright 2014 Fen Logic Ltd. The copyright is on the manual as well as the instruction set