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ghmartin77 / B-ROBOT_EVO2_ESP32

ESP32 port of JJRobots brilliant B-ROBOT_EVO2
GNU General Public License v2.0
57 stars 32 forks source link

Issues with stepper motors #2

Open shameed123 opened 3 years ago

shameed123 commented 3 years ago

Hi,

This project is exactly what I was looking for. ESP32 based B-Robot Evo2. Thank you for making it available.

I built the robot with the 3D printed body of early version of Evo here: https://www.thingiverse.com/thing:700637

I am using a CNC shield for now to avoid dealing with capacitors and resistors for a4988 drivers. I am also using 3x 18650 battery pack.

When I turn on the robot laying on the floor, it goes through calibration and moves the wheels a little bit I guess to indicate that the calibration is complete. The motors remain disabled. But when I put it on its legs (sort of), the motors kick in and the wheels start moving. I run into two issues:

  1. If the robot is touch the floor, the motors almost immediately run into this state where they whine and scream, but the shaft is not moving. Basically for a second or so after making it stand up, the wheels turn, but soon after the wheels stop turning and the motors make weird sound.
  2. If I don't keep the robot on the floor, the motors turn fine. The turn in one direction while the robot is up right. If I tilt the robot in one direction, the motors decelerate and then start turning in the other direction. I tilt the robot in the other direction, the motors decelerate again and then starts rotating in the other direction.

The #1 above is a problem. I am not sure if #2 is expected or that's a problem too, because I can't test it while keeping the robot on the floor due to #1 issue.

I was wondering which Nema 17 motors are you using? I am using 17HS4401. They seem to be powerful enough.

The 3x 18650 batteries I am using are providing 11.5V and each battery is capable of delivering 7A, so that should be plenty.

I also tuned the Vref on A4988 to 1.2V to match with my motor specs.

I have my MPU6050 installed in the same direction as in your picture.

I am not sure what I am doing wrong. Any suggestions would be helpful.

I am attaching some pictures here:

IMG_20210331_163501 IMG_20210331_163511 IMG_20210331_163521

moelski commented 2 years ago

Same Problem here ... Did you fix this issue in the meantime - and how ?