Servo Jetson Nano

I try to use this dockerfile to control servo:

# Base l4t container with Jetpack 5.0

WORKDIR /usr/src/car/utils

ADD . /usr/src/car/utils

RUN apt-get update

RUN apt-get install -y python3-opencv && apt-get install -y python3-pip

# Setting up Servo control
RUN apt-get install -y python3-pip
RUN pip3 install Jetson.GPIO
RUN apt-get install -y python3-smbus
RUN usermod -aG i2c root
RUN groupadd -f -r gpio
RUN usermod -a -G gpio root

Then I run the container using command docker run -it --runtime nvidia --volume /dev/video0:/dev/video0 --device /dev/video0 --volume /home/vovinsa/Documents/SelfDrivingCar/car/utils:/usr/src/car/utils --volume /tmp/argus_socket:/tmp/argus_socket --volume /dev/i2c-1:/dev/i2c-1 --device /dev/i2c-1 9b and use this simple script to control servo:

from servo import Servo

pwm = Servo()

pwm.set_rotation_angle(channel=0, angle=180)

P.S. the Servo class:

import time
import math
import smbus

class Servo:

    Control Servo Jetson Nano

    __SUBADR1 = 0x02
    __SUBADR2 = 0x03
    __SUBADR3 = 0x04
    __MODE1 = 0x00
    __MODE2 = 0x01
    __PRESCALE = 0xFE
    __LED0_ON_L = 0x06
    __LED0_ON_H = 0x07
    __LED0_OFF_L = 0x08
    __LED0_OFF_H = 0x09
    __ALLLED_ON_L = 0xFA
    __ALLLED_ON_H = 0xFB
    __ALLLED_OFF_L = 0xFC
    __ALLLED_OFF_H = 0xFD

    def __init__(self, address=0x40):
        self.bus = smbus.SMBus(1)
        self.address = address
        self.write(self.__MODE1, 0x00)

    def write(self, reg, value):
        self.bus.write_byte_data(self.address, reg, value)

    def read(self, reg):
        result = self.bus.read_byte_data(self.address, reg)
        return result

    def set_pwm_freq(self, freq):
        prescaleval = 25000000.0  # 25MHz
        prescaleval /= 4096.0  # 12-bit
        prescaleval /= float(freq)
        prescaleval -= 1.0

        prescale = math.floor(prescaleval + 0.5)

        oldmode =
        newmode = (oldmode & 0x7F) | 0x10  # sleep
        self.write(self.__MODE1, newmode)  # go to sleep
        self.write(self.__PRESCALE, int(math.floor(prescale)))
        self.write(self.__MODE1, oldmode)
        self.write(self.__MODE1, oldmode | 0x80)
        self.write(self.__MODE2, 0x04)

    def set_pwm(self, channel, on, off):
        self.write(self.__LED0_ON_L + 4 * channel, on & 0xFF)
        self.write(self.__LED0_ON_H + 4 * channel, on >> 8)
        self.write(self.__LED0_OFF_L + 4 * channel, off & 0xFF)
        self.write(self.__LED0_OFF_H + 4 * channel, off >> 8)

    def set_servo_pulse(self, channel, pulse):
        pulse = pulse * 4096 / 20000  # PWM frequency is 50HZ,the period is 20000us
        self.set_pwm(channel, 0, int(pulse))

    def set_rotation_angle(self, channel, angle):
        if 0 <= angle <= 180:
            temp = angle * (2000 / 180) + 501
            self.set_servo_pulse(channel, temp)
            print("Angle out of range")

    def exit_servo(self):
        self.write(self.__MODE2, 0x00)

And it doesn’t work
Also I have trued to import Jetson.GPIO in the container and I have this error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.8/dist-packages/Jetson/GPIO/", line 1, in <module>
    from .gpio import *
  File "/usr/local/lib/python3.8/dist-packages/Jetson/GPIO/", line 33, in <module>
    raise RuntimeError("The current user does not have permissions set to "
RuntimeError: The current user does not have permissions set to access the library functionalites. Please configure permissions or use the root user to run this

How can I fix this?

hello vovinsa,

that failure shows The current user does not have permissions, please check you have added the user to the group correctly.
you may use who command to check your user name, or, using this command… usermod -a -G gpio $USER

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