Python library for the Pololu Dual MAX14870 Motor Driver for Raspberry Pi
Release Date: 2018-04-03
This library runs on the Raspberry Pi (Model B+ or newer) and provides functions for controlling both channels of the Pololu Dual MAX14870 Motor Driver for Raspberry Pi. This library supports both Python 2 and Python 3.
This library depends on pigpio, and the instructions below explain how to set it up.
These instructions assume you are using Raspbian, Debian, or some other
distribution that provides the
apt command for managing packages. If you do
apt, you will need to use a different method to install the required
These instructions also assume you will use Python 2. If you want to use Python 3, you will need to:
- install the
python3-pigpiopackage instead of
python-pigpio(it is okay to install both)
- use the
python3command instead of
pythonfor running Python scripts
First, to download and install pigpio and its Python module, run:
sudo apt install python-pigpio
Then, to start the
pigpiod daemon, run:
sudo systemctl start pigpiod
Optionally, to automatically start the daemon every time your Raspberry Pi boots, you can also run:
sudo systemctl enable pigpiod
Finally, to download and install the dual_max14870_rpi library, run:
git clone https://github.com/pololu/dual-max14870-motor-driver-rpi cd dual-max14870-motor-driver-rpi sudo python setup.py install
Running the example program
This library comes with an example program that drives each motor in both directions. To run the example, navigate to the dual-max14870-motor-driver-rpi directory and run:
This library uses ultrasonic 20 kHz PWM to drive the motors.
Motor speeds in this library are represented as numbers between -480 and 480 (inclusive). A speed of 0 corresponds to braking. Positive speeds correspond to current flowing from M1A/M2A to M1B/M2B, while negative speeds correspond to current flowing in the other direction.
The library can be imported into a Python program with the following line:
from dual_max14870_rpi import motors, MAX_SPEED
After importing the library, you can use the functions below to enable the motors and set motor speeds:
motors.enable(): Enable the motor drivers.
motors.disable(): Disable the motor drivers.
motors.setSpeeds(m1_speed, m2_speed): Set speed and direction for both motor 1 and motor 2.
motors.motor1.setSpeed(speed): Set speed and direction for motor 1.
motors.motor2.setSpeed(speed): Set speed and direction for motor 2.
Trueif there is a motor driver fault,
Falseif no fault.
For convenience, a constant called
MAX_SPEED (which is equal to 480) is
available on all the objects provided by this library. You can access it
directly by just writing
MAX_SPEED if you imported it as shown above, or it
can be accessed in the following ways:
If you are controlling multiple motor drivers, you might prefer to import the
import dual_max14870_rpi, which requires the commands listed
above to be prefixed with
- 1.0.1 (2018-04-03): Improved error behavior and exception handling.
- 1.0.0 (2018-03-30): Original release.