Motors don't run (motor-driver ROB-13911)

Hi, I have trouble with running motors with code below on Jetson Nano:

from jetbot import Robot

robot = Robot()

a = 1

while a == 1:
    robot.forward(speed=0.4)
    print(robot.left_motor.value)
    print(robot.right_motor.value)

Code runs without any errors (print output gives “0.4” value), but motors connected to motor-driver don’t work. I also tried to use JetBot examples https://github.com/NVIDIA-AI-IOT/jetbot/wiki/examples but code from basic-motion.ipynb also doesn’t work. I measured voltage on motor connections, but it looks there is no voltage on output.

https://cdn.sparkfun.com/assets/learn_tutorials/5/7/4/FrontAnnotated01.png

I’m using SparkFun JetBot AI Kit with JetPack 4.2.2.

I connected everything as in official guide: https://learn.sparkfun.com/tutorials/assembly-guide-for-sparkfun-jetbot-ai-kit/all#introduction

Red LED of ROB-13911 motor-driver is blinking.

I used sudo i2cdetect -y -r 1 and see that motor-driver is under address 0x5d (as in official guide, because of soldered #3 jumper of motor-driver)

0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- 3d -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- 5d -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

I also changed addres and i2c_bus of motorHat init in ~/Adafruit-Motor-HAT-Python-Library/Adafruit_MotorHAT/Adafruit_MotorHAT_Motors.py before setup (I did it beacuse of IOError: [Errno 121] Remote I/O error with default address)

from:

def __init__(self, addr = 0x60, freq = 1600, i2c=None, i2c_bus=None):

to:

def __init__(self, addr = 0x5d, freq = 1600, i2c=None, i2c_bus=1):

That allows me to run code, but motors still don’t work, and measured voltage on motor connections is 0 [V].

I also ordered new motor-driver (ROB-13911) but I have still same problem.

Could I ask for help with starting the motors?

Reflashing SD card to jetbot_image_v0p4p from https://github.com/NVIDIA-AI-IOT/jetbot/wiki/software-setup
solved the problem.