DC motor interface with Teensy without encoder (pins)

[Aarlex]

Hi Juan,

 

I have one question. I have several motors lying around. The problem is they are simple dc motors 6v - 12 v with no encoders on them. Just two terminals for the motor power.(+ and - terminals) In this case, will the linorobot code work as there are no encoder A, B, VCC pins to connect to the teensy. Does linorobot generate odometry only from the IMU or it fuses both encoder and IMU. I plan to try making a 4wd version from the motors using the GY85 IMU. 

Thanks

Alex

[Juan Miguel Jimeno]

I've just updated the minimal branch. This branch doesn't require any sensor (IMU, Encoder) but there will be no Odometry data published from the robot. You can drive the robot around using teleop package but I doubt this setup can navigate autonomously with the current launch files.

You can still implement a PID controller if you use an external source of odometry (i.e. Visual Odom.). The PWM values to drive the motor will be calculated using the Twist msgs from ROS vs the velocities from your external odom. This is not necessary for this purpose but good to have. This option is available at the bottom of the moveBase function (commented).

Thanks for opening this up, realized that it'll will be good to have a much comprehensive minimal branch which can navigate autonomously yet without having an IMU and Encoders. Probably use laser_scan_matcher package as a source of odometry and use hector mapping to replace gmapping.
Will post it here once I get it done.

Hope these help. Happy hacking!

[Aarlex]

Hi Juan,

Thanks for the update. This is a nice addition. I will update once I test this branch. 

Alex