ghmartin77 / b-robot_evo2_esp32 Goto Github PK

Due to changes in the ESP32 core, some small changes are needed to successfully compile.

This is the error message generated on compiling with ESP32 core 1.06 on the latest Arduino 1.8.16

call of overloaded 'requestFrom(uint8_t, size_t, bool)' is ambiguous

This PR should address the issue #3

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:

Hi !
First of all thx for this code. We try to build the B-Robot and come along with a problem reading the Gyro.

// MPU6050_read n bytes
int MPU6050_read(int start, uint8_t *buffer, int size)
{
  int i, n, error;

  Wire.beginTransmission(MPU6050_I2C_ADDRESS);
  n = Wire.write(start);
  if (n != 1)
    return (-10);

  n = Wire.endTransmission(false);    // hold the I2C-bus
    if (n != 0)
       return (n);

Wire.endTransmission(false) returns no longer a value like 0. It returns a value of 7 because the data transfered to the I2C device is queued. And the result is a not working MPU6050.
Even rewriting the part to check for n != 7 didn´t work correctly.

So did you ever compile your sketch against the latest git master of the ESP32 Arduino Core?

Would be great if you can make a test and come back maybe with a fix.

regards
Dominik