Let's Make Robots!

4 Motors on a 28 pin Project Board (AXE020)

I am looking to upgrade my first robot which is built from the LMR Starter Bundle. I to start out I would like to upgrade to 4 motors. Currently I only see the A & B pins for motor control. The motors do not need to be independently controled, I only need to be able to control 2 at a time. Is this doable?

Also, I eventually want to upgrade to bigger motors, would it be easier instead using 4 triacs or relays?


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The Picaxe 28x1 only has 8 digital outputs. On the Picaxe-28 project board, outputs 4,5,6 and 7 are used to drive the A & B motor outputs.

If you want to independently drive four motors, you'll need all 8 digital outputs, plus another dual h-bridge motor driver on an external board. If you can find a motor driver board that includes its own microprocessor and supports i2c, you could probably off-load all motor control to one or two external boards and free up the Picaxe for more sensors, actuators, etc.

Alternatively, if you want four driven motors, but the two left motors are in sync and the two right motors are in sync, you could try an arrangement like DAGU's Mr Basic kit, where there is a drive chain for each side of the bot, with one motor driving each pair of wheels.