Before I posted, I searched and searched, and disappointed that could not find anyone else having the same problem. I’m using two Pololu item #: 1121 (Solarbotics) gearboxes, connected to my baby-O motor outputs. Everything is ok, very nice parts to work with. I’m powering my baby-O with four rechargeable AA batteries. The problem is that when I run the motors near half speed, it resets my baby-O, sometimes it will reverse one of the motors, without me telling it to do so. I have put caps at the motor leads and also at the baby-O power cables. The motors are not working at full load.
Is there way to work around this? Is there a way to separate the power to the Atmeg328p and the motor driver? Should I even try? The simple obvious solution would be to replace the Pololu item #: 1121 (Solarbotics) gearboxes with servos, or add another qik 2s9v1 dual motor driver Pololu item #: 1110.
It sounds like you are having a power issue. The nominal voltage of a rechargeable AA battery is 1.2V. If you have 4 in series, their voltage is only 4.8V, which is not sufficient for powering the Baby Orangutan. I recommend adding at least one additional battery to ensure the Baby Orangutan stays within its operational voltage range when driving the motors.
It is possible to separate the power to the ATmega328 and the motor driver; however, it would probably require tools for removing surface mount devices.
Thanks Jeremy for the obvious truth.
I know that four rechargeable AA batteries equals 4.8 volts, what I don’t understand is, how did I miss it! The big clue was that the baby-O has a regulated 5 volt output pin, I never asked how can it get 5 volts out of a 4.8 volt input!!!
Instead of using five rechargeable AA batteries, I just used four AA alkaline batteries to test it, and this did it, the motors did not reset the baby-O and it accepted and executed the rest of my motor commands. I still have other problems however, but I’m sure that I can get rid of them or find a work around much easier now.
This is the robot that I’m working on:
flickr.com/photos/96504930@N … 864298954/
I am glad you got it working. Your robot looks fun. I would be interested in making a blog post about it on our blog. Do you have your project documented someplace or videos of the robot moving?
By the way, alkaline batteries can have large voltage drops during high current draws. With just 4 alkaline batteries, you might still encounter brownout, so I still recommend adding an additional cell.
Agreed, that’s the next step, to make it five AA rechargeable batteries. I will have to change the battery holder to accommodate the five batteries.
Now that I’m getting past this problem, I will be moving forward to refine the documentation and get some videos moving. The crux of the bot is that it’s run by an Android cheap phone. No service contract needed just Bluetooth, and Pololu parts, and most important of all, a Basic interpreter Android App available from googlePlay. Anybody can write in Basic, kids did it back in the 1980’s.