I will start from saying that the board could be replaced by any Arduino plus some(s) its motor driver shield(s). So why I made it you may ask? Well, while I made this tiny tank-robot model presented on below pictures, I wanted to make at least some things by myself, and decide what I need and how I need it instead of only buying prefabricated stuff.
This is the result, hope you will enjoy it and that maybe you will find inspirations for your own stuff.
Her's what it has and what it can..
- Handle two separate motors, each can run either "forward", "backward", or stop.
- Motors can be powered from a separate power source (there's a jumper for that, if removed, power is taken from a source connected to a separate goldpin)
- ATtiny24 manages the board, it's relatively small microprocessor, but I think that it will be fine for such project. All its pins are available via goldpins, I also added a couple goldpins connected to Vcc and GND to make easier connection to other boards, shields and stuff like that.
- To make programming easier, 6 PINs ISP socket for the ATtiny24 is also included.
- ATtiny24 can be removed and the motor driver can be managed from external source, e.g. an Arduino. This could be useful in future if the ATtiny24 would not be sufficient.
- There isn't any voltage regulator, or step/up/down/ converter because it would make the board less flexible.
The hardware was designed in Eagle, the board is available on GitHub.
PB0, PB1, PB2 and PB3 ports of the ATtiny24 are used to drive the motor, others are available for other purposes, e.g to communicate with the sensors. There's not a lot of them left, because the microprocessor is quite small, but I think that for such project, it will be enough.
The code was developed in AtmelStudio, and is available on GitHub (the same repository as the hardware part). It's just a big hack to check if it's working, not really high quality.
Everything works as expected and I'm happy with the results. The PCB is quite poor made because I din't have a proper drill, so I destroyed a bit of traces, it took me time to make them works. The drills for screws could be placed in bigger distance from from traces to avoid shortcuts. Another thing is that if I would make this board again, I would use 90 degree goldpins - they would be easier accessible.
Since I didn't plug any sensors I don't have any films to show how the tank behaves. I will add them, when this will be done.