minisumo

Forum 2005-2010 (read only) Hardware Interfacing
1

i am up to develop mi 1st minisumo using arduino duemilanove

i need advice about:

  1. battery pack: voltage (number of cells?)

  2. Arduino power supply (directly to battery or via voltage regulator?)

  3. motor power supply (L293D is ok? may cause critical noise on power rails?)

thanx

2

  1. Battery pack size will depend on your motors

  2. Probably best to use a separate battery for the Arduino to avoind problems with noise from the motors.

  3. Choice of H-bridge chip depends on current drain of your motors

Please tell us more about the design! We really need to know the specifications of the motors, at least.

3

at the time there is not a design and no specifications...
i am trying to organize ideas to make this design :slight_smile:

the idea is to use single supply battery to minimize complexity
so the battery have to feed the arduino and the motors

i think 6 cells (7.2v) could be ok for arduino

motors could be modified servo for continuous rotation or gear motors...

but 7.2 is too much for servos, i have to chose between two setup i think:

  1. battery -> 5v voltage regulator -> servo
    or
  2. battey -> L293 bridge -> gear motors
4

A single battery will make the robot simpler, but you may find that the Arduino crashes unexpectedly due to noise. But, either of those two schemes should work OK.

5

probably, using a single supply, the key is to use motors which produce low noise... On other robots i have found that gearmotors based on brushles solar motors are ok and do not disturb micro....

those are very cheap and low torque but works fine

so i will try this way...
btw what is the right strategy to suppress noise on power rails produced by motors? ... other than usual decoupling caps..

6

Its called a PI filter, so called because it resembles the greak letter. basically, its a inductor in the power line between the motor and arduino, and two caps either side of the inductor, from the supply to ground. Good luck!

7

excellent tip phill
i will thy this solution

so i have to place a PI filter between Arduino and L293D Supply Voltage pin

well, I have 2 question for you:

  1. On which side of the PI filter have I to connect batteries? (arduino side or motordriver side)

  2. in my bitbox i have two inductors: 22uH and 100uH, which one could be more appropiate for the purpose?

many thanx

8

up
plz