Happy New Year, everyone.
My Rolly robot project in February and March 2013 issues of APC magazine has been a huge hit and I’m still getting lots of feedback and questions.
However, there seems to be an issue for some where only one motor seems to spin and Rolly ends up going around in circles.
The second part of this project in the March 2013 issue indicated that one of the motor drive controls was switched from M2 to M4 on the Motor Drive Shield, however, I have to assume given the number of queries, those having this problem haven’t read the second part of the feature.
Anyway, the reason for the change from M2 to M4 is that M4 is located on the second of the two L293D driver chips, the idea being to spread the load and reduce the heat produced by having both motors driven by the one L293D chip. (I was surprised by how hot the one L293D chip was getting, given the motors weren’t pulling that much current – spreading the load reduced the temperature, which means the board should last considerably longer).