is there any hw and arduino board/micro that would allow us to create small robot cars of about 5-8 cm?
If you are talking about putting an Arduino inside a model car that is no longer than 8cm then none of the standard Arduino boards would be small enough.
You have not said if you envisage radio control.
I have made this reasonably compact radio control package for 00/HO model trains using an Attiny84, nRF24L01+ wireless transceiver and a Rohm BD6212 motor driver. The nRF24 forms the base of the package and it measures 29mm x 15mm. It is powered by a 1S LiPo
...R
The Pro Mini is 18x33 mm, that should fit in such a car.
Even the Nano, 18x43 mm in size, should fit.
Nonetheless it's probably one of those projects where you're going to want a custom PCB for the final one, to really shrink it down and have just what you really need, nothing more and nothing less.
wvmarle:
The Pro Mini is 18x33 mm, that should fit in such a car.
Even the Nano, 18x43 mm in size, should fit.
I suspect they would not be sufficient on their own.
And in my case a PCB would have made the thing too thick. I don't have the knowledge to design a complete system on a PCB using surface mount components - and I only need a few of them.
It is possible to buy a complete Deltang system which has a very small PCB - but they are not cheap. Examples of what can be done here
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