Generation 2 Electronics
Contents
Generation 2 Electronics
Once you start putting electricity into your RepRap - even at just 12 volts - you have to take basic, common sense precautions to avoid fires. Just in case these fail, test your workshop smoke detector. Got no smoke detector? Get one!
Wires and Connectors
Electronics are no good on their own, they need to be connected together in order to do something really useful. Obviously you're going to want to use some sort of wire, but which one and how will you connect it?? Dont worry, because in this guide we will attempt to simplify it for you.
Power Supply
The RepRap machine needs a regulated power supply giving at least 8 amps at 12 volts. The easiest way to do this is to convert a normal PC power supply into a RepRap power supply.
Arduino & Arduino Clones
Arduino is an open source project that has created an easy and powerful microcontroller board. It is the brain of the RepRap electronics. You can get a premade Arduino, you can buy a kit, or you can even make it from scratch yourself. They all look the same to the rest of the electronics or to your computer.
PowerComms Card v1.3
The Power / Communications card is the link between the computer and the RepRap printer. It uses RS232 to communicate over a serial port. If you do not have access to a serial port on your computer, there are widely available USB -> RS232 converters available. It also distributes the 12v power via connectors for all the other boards.
Signals are passed from the RS232 around the communications ring until they arrive at the device to which they are addressed, which then acts upon them. Thus the RS232 Transmit from the Communications board goes to the Receive on the first controller; that board's Transmit goes to the next board's Receive.
Stepper Motor Driver v1.1
Each stepper driver board drives one of the stepper motors. You need three of these boards for a fully functioning RepRap. Each board controls the position of one axis. Together, they position the print head anywhere in the 3 dimensional build area.
DC Motor Driver v1.0
This board is capable of controlling two low current DC Motors in both forward and reverse. It has a speed/direction interface and is easy to control.
PWM Driver v1.0
This board is capable of driving medium DC loads with TIP120 power transistors. It has a PWM interface and is also easy to control.
Opto Endstop v1.0
All of a RepRap's axes all need a datum (also known as home position or end-stop) to reference their movements. At the start of each build each axis needs to back up until the datum point is reached. We use one opto-switch for each axis to define its position. This page tells you how to wire one up.
Temperature Sensor v1.0
This sensor allows you to read a thermistor as an analog value. It is a very small and simple helper board.
