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Motoron Motor Controller library for Raspberry Pi
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This is a Python 3 library that helps interface with Motoron motor controllers using I²C or UART serial.
It supports the following Motoron controllers:
This library is designed to run on any Python 3 or MicroPython interpeter that has a working (including access to compatible hardware) version of one of the following Python libraries:
We have mainly tested this library on Raspberry Pi single-board Linux computers and MicroPython-compatible RP2040 development boards such as the Raspberry Pi Pico.
This library does not support Python 2.
Run the following commands to install prerequisities, download this library, and install this library:
sudo apt install git python3-dev python3-pip sudo pip3 install smbus2 git clone https://github.com/pololu/motoron-python.git cd motoron-python sudo python3 setup.py install
You will also need to enable I²C, figure out which I²C bus to use, set up the I²C device permissions properly (so you do not have to use sudo), and connect the Motoron to your Raspberry Pi's I²C bus. If you are not sure how to do those things, see the "Getting started" sections of the Motoron user's guide.
The examples relevant to this setup are named i2c_*.py. Run ./i2c_simple_example.py inside the library directory to execute the simplest example.
Run the following commands to install prerequisities, download this library, and install this library:
sudo apt install git python3-dev python3-pip sudo pip3 install pyserial git clone https://github.com/pololu/motoron-python.git cd motoron-python sudo python3 setup.py install
You will need to make sure that your machine has a serial port that pySerial can connect to. This is typically an integrated serial port that is part of your computer or a USB-to-serial adapter.
On the Raspberry Pi, we recommend using /dev/serial0. You can check if it exists by running ls -l /dev/serial*. If it does not exist, you should enable it by running sudo raspi-config nonint do_serial 2 and rebooting. You should also add yourself to the dialout group by running sudo usermod -a -G dialout $(whoami), logging out, and logging back in again.
The examples relevant to this setup are named serial_*.py. Run ./serial_simple_example.py inside the library directory to execute the simplest example.
The examples that work with MicroPython have names starting with mpy_. You can run one of these examples by renaming it to main.py, copying it to your board, and then rebooting your board. The files motoron.py and motoron_protocol.py also need to be copied to the board.
FileNotFoundError: [Errno 2] No such file or directory: '/dev/i2c-1'
The error message above indicates that I²C bus 1 was not found. For most users, the solution is to run sudo raspi-config nonint do_i2c 0 to enable I²C bus 1 and then reboot. You can see which I²C busses are enabled by running ls /dev/i2c*. If you have connected your Motoron to a different I²C bus, you should specify the bus number when creating the MotoronI2C object. For example:
mc = motoron.MotoronI2C(bus=123)
serial.serialutil.SerialException: [Errno 13] could not open port /dev/serial0: [Errno 13] Permission denied: '/dev/serial0'
The error message above indicates that your user does not have permission to access /dev/serial0. On a Raspberry Pi, you can fix this by running sudo usermod -a -G dialout $(whoami), logging out, and logging back in again.
serial.serialutil.SerialException: could not open port 'COM8': PermissionError(13, 'Access is denied.', None, 5)
The error message above occurs on Windows if another program is using the serial port you are trying to open.
The essential code for the library is in just two files: motoron.py and motoron_protocol.py.
Several example programs come with the library. They are single-file Python programs that have names ending with _example.py.
The main classes provided by this library are motoron.MotoronI2C and motoron.MotoronSerial. Each of these is a subclass of motoron.MotoronBase.
For complete documentation of this library, see the motoron-python documentation. If you are already on that page, then click the links in the "Classes" section above.
By default, the Motoron will turn off its motors if it has not received a valid command in the last 1.5 seconds. You can change the amount of time it takes for the Motoron to time out using motoron.MotoronBase.set_command_timeout_milliseconds or you can disable the feature using motoron.MotoronBase.disable_command_timeout.
read_eeprom and get_variables methods now return bytes objects instead of a list of integers, which allows the return value to be used with int.from_bytes and struct.unpack in MicroPython. Pass the return value to list() if you want a list.get_vin_voltage_mv method now takes an optional type parameter to specify what scaling to apply. 1.9.6