micropython-bot

driving software for a simple micropython bot. made for beginners.

requirements

• esp32 or esp8266 (not tested)
• https://github.com/rsc1975/micropython-hcsr04 library (included in codebase)
• bot specs in robot.md

API reference (robot.py)

robot - main library for the robot.

import robot - imports the robot library.

Global Variables

robot.CLOCKWISE - defines clockwise for robot.motors.spin()

robot.COUNTERCLOCKWISE - defines counterclockwise for robot.motors.spin()

robot.MOTOR_A - pin for right motor clockwise. (defined as 32)

robot.MOTOR_B - pin for right motor counterclockwise. (defined as 33)

robot.MOTOR_C - pin for left motor clockwise. (defined as 12)

robot.MOTOR_D - pin for left motor counterclockwise. (defined as 13)

robot.FRONT_SERVO - pin for front servo (defined as 14)

robot.SR04_TRIG - pin for the SR04 module's trigger. (defined as 25)

robot.SR04_ECHO - pin for the SR04 module's echo. (defined as 26)

Classes

robot.motors - preinitialized MotorController object.

robot.servo - preinitialized Servo object.

robot.sensor - preinitialized UltrasonicSensor object.

Methods

• robot.halt() - command to stop all motors and move the servo to angle 0.

• robot.motors.halt() - command to stop all motors.

• robot.motors.calibrate(left, right) - calibrates left and right motors

  • float left: left calibration % (0-200)
  • float right: right calibration % (0-200)

• robot.motors.rightMotor(speed) - sets speed of right motor.

  • float speed: speed between 0 and 100

• robot.motors.leftMotor(speed) - sets speed of left motor.

  • float speed: speed between 0 and 100

• robot.motors.forward(speed, ms) - moves the robot forward for a specified period of time.

  • float speed: speed between 0 and 100
  • int ms: time to move in ms
  • boolean halt(optional): whether to halt after movement (default=True)

• robot.motors.backward(speed, ms)- moves the robot backwards for a specified period of time.

  • float speed: speed between 0 and 100
  • int ms: time to move in ms
  • boolean halt(optional): whether to halt after movement (default=True)

• robot.motors.turnLeft(speed, ms) - makes the robot turn left for a specified period of time.

  • float speed: speed between 0 and 100
  • int ms: time to move in ms
  • boolean in_place(optional): whether to turn in-place or rotate
  • boolean halt(optional): whether to halt after movement (default=True)

• robot.motors.turnRight(speed, ms) - makesthe robot turn right for a specified period of time.

  • float speed: speed between 0 and 100
  • int ms: time to move in ms
  • boolean in_place(optional): whether to turn in-place or rotate
  • boolean halt(optional): whether to halt after movement (default=True)

• robot.motors.spin(speed, dir, ms) - makes the robot spin in place

  • float speed: speed between 0 and 100
  • int dir: robot.CLOCKWISE or robot.COUNTERCLOCKWISE
  • int ms: time to spin in ms
  • boolean halt(optional): whether to halt after movement (default=True)

• robot.servo.setAngle(angle) - sets the angle of the servo

  • int angle: angle between -90 and 90 (by default)
  • boolean delay(optional): whether to delay until the servo is done moving

• robot.servo.getAngle() - gets the intended angle of the servo

  • return (int) the angle of the servo. may not exactly match robot.servo.setAngle()

• robot.sensor.getDistance() - gets the current distance measured by the ultrasonics sensor.

  note: please do not call this more than around 10 times a second. accuracy is greatly diminished.

  • return (float) the distance measured by the sensor in centimeters (cm).

how to use MicroPython

Make sure you're using uPyCraft or Thonny or any other MicroPython IDE. I recommend uPyCraft. Here's a good quick-start tutorial for it.

Connect to your controller (on Windows, it's a COM port, and on Linux, it's probably /dev/ttyUSBx)

MicroPython controllers run Python in this fashion:

reset or start -> boot.py -> main.py -> REPL

I recommend putting your imports in boot.py. Just make sure it includes:

• import robot
• import os (in most cases)

In most cases you'll be running your code in main.py (so a REPL command isn't needed), so your code will have to go there. To reference and run another script on the MCU just import script inside main.py.

To test the robot library you can import test in main.py. test.py is a testing program that tests all functionality of a basic robot outlined in robot.md.

modifying robot.py

to make my robot.py work with your robot, you may have to

• change definitions:

SERVO_MIN - minimum duty out of 1024

SERVO_MID - midpoint (0 degrees) duty out of 1024

SERVO_MAX - maximum duty out of 1024

SERVO_FREQ - frequency of PWM driving servo

SERVO_ANGLE - angle range of servo when converting from angle to duty

MOTOR_OFF - minimum duty of motor out of 1024

MOTOR_MAX - maximum duty of motor out of 1024

MOTOR_FREQ - frequency of PWM driving motors

• add more servos

create more Servo objects around line 245

if you're doing more than that I assume you know what you're doing.