I am about to start my first Arduino-based project. I have used Lego Mindstorms NXT with TETRIX, additional sensors and the programming language ROBOTC for years, however, I am completely new to electronics as well as Arduino.
To begin with, I want to build a robot only some wider and longer than the Arduino Uno R3, which I will be using. The robot needs to have 6 wheels/motors (3 motors on each side), if possible, and one of the motors on each side needs to have an encoder. I am planning to use the official Arduino Motor Shield found on the Arduino site.
Since I am completely new to electronics I find it hard to know what is possible or impossible, although I have done some research on the internet. I see that the board supports maximum 4A (2A per channel) and operates between 5V and 12V. So,
- Since I need 3 motors on one side operating synchronously and 3 motors on the other side operating synchronously, how should I connect each side-pair of motors? I guess they should be connected in parallel?
- What are my limitations of choice of motors, if I need 6 motors on one board? Would six of these motors (http://www.pololu.com/catalog/product/2364) work, since their total stall-current would be 4,2A? (and does this even matter, or does it has to do with something completely else?)
- What (type of) batteries should I be looking for? They should be rechargeable. I also believe I will need one battery for the Arduino Uno and the Motor Shield, and another battery for the motors?
- What (electrical) components will I need? On-off switches, resistors, some sort of connectors etc.? I might be able to figure this out myself, I am just afraid to burn something or fry any circuits before I even get started!
If this should be posted elsewhere or has already been answered somewhere, please let me know. Also let me know if I need to explain something further. And sorry if this is "basic knowledge", but I have looked quite a lot in the internet but still could not figure this out...
Thank you so much in advance! :-)
If the motors need to go both directions then each needs a full H-bridge (so dual H-bridge chips are limited
to two motors each). I don't think there are shields for more than 4 motors, seems unlikely.
If motors only have to turn one way then a single logic-level MOSFET is needed for each, driven from a PWM pin,
this is more likely to be available as a shield?
Well, I have 6 motors whereof 3 motors should work synchronously as ONE motor (so that if one motor spins, brakes or changes direction the other two does too), and the other 3 should work synchronously as one motor too. If I connected 3 motors in parallel and connected these to + and - in the screw terminal A, and then connected the other 3 motors in parallel and connected these to + and - in the screw terminal B, would that work? :-) Or would I destroy something?