Microbit Python Driver for PCA9685
A simple python class for using the PCA9685 16-Channel 12-bit PWM/Servo Driver - I2C interface (https://www.adafruit.com/product/815).
Using the driver
There is an example of how to use the driver to control a server in main.py but it can be used to control motors and LEDS as well. The example sets the servo at channel 0 to it's minimum value, sleeps for 1 second, then set's channel 0 to it's maximum value:
pwm.set_pwm(0, 0, servo_min) sleep(1000) pwm.set_pwm(0, 0, servo_max) sleep(1000)
If you do not know how to load additional files onto your microbit (so main.py can read the PCA9685 driver from PCA9685.py) read https://microbit-playground.co.uk/howto/add-python-module-microbit-micropython.
There is now a servo helper class in servo.py based on https://github.com/adafruit/micropython-adafruit-pca9685/blob/master/servo.py that makes it easier to set a servo position in degrees (the default), radians, microseconds or directly as a number between 0 and 4095 signifying the duty cycle. There is an example using degrees in the main.py that also demonstrates the 'release' method that stops sending a message to the servo, releasing it.
This driver is adapted from Tony DiCola's driver at https://github.com/adafruit/Adafruit_Python_PCA9685/blob/master/Adafruit_PCA9685/PCA9685.py
I am an experienced software developer but very new to Python and I2C. There are bound to be many improvements that could be made to the basic code as well as new helper classes. If you wish to contribute feel free to send PR's and chat to me on http://microbit-community.slack.com username 'MicroMonsters'.
Don't forget to check our youtube channel http://youtube.com/c/micromonsters to find inspiration using the microbit to code with your children.