OHMC2020 Troubleshooting guide

Check the I2C components are working
$ i2cdetect -y 1 0 1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --   20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --    30: -- -- -- -- -- -- -- -- -- -- -- -- 3c -- -- -- 40: 40 -- -- -- -- -- -- -- -- -- -- -- -- 4d -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --   60: -- -- -- -- -- -- -- -- 68 -- -- -- -- -- -- --    70: 70 -- -- -- -- -- 76 --      GY-91 10DOF MPU-9250 & BMP280 0x3C - OLED Display (SSD1306_128_64) 0x40 - PCA9685PW: Normal use (PWM / servo) 0x4D - MPC3021 (battery volt ADC) 1001101X 0x68* - MPU9250 (gyroscope/accelerometer sensors) 0x70 - PCA9685PW: All call address (PWM / servo) 0x70 - PCA9685PW (PWM / servo) 0x76* - BMP280 (pressure)

If the output doesn't look like this, something isn't being detected properly and your car may not be working as expected.

rPi reboots and Auto-starting donkeycar without logging in
If your rPi reboots when you're driving, check the following things: Because the battery has a high internal resistance, if you demand a lot of power too quickly, the voltage on the battery drops enough that the rPi gets below its critical voltage (when you add the voltage drop from the voltage converter), and the rPi reboots.
 * 1) did you swap the servo wires between steering and power. Turn the ESC off, unplug one servo wire, turn the ESC back on (little toggle switch), and test steering. Make sure that steering does not activate the wheel motors.
 * 2) is your battery low? are you accelerating too quickly?

To restart donkey server automatically, do the following on your car: su - pi -c 'cd ~/ohmc_car; python manage.py drive &>/tmp/out' &
 * Add this to /etc/rc.local:
 * move 'source ~/env/bin/activate' from ~/.bashrc to ~/.profile

Steering and throttle calibration
To save time at the workshop, you won't need to calibrate your car's steering and/or throttle. However, you may get better results and can perform calibration when you have time.

DonkeyCar instructions on calibration