Coffee Scale

Simple python code base to read binary data from a Dymo M10 scale

Example Usage

1. Setup a Raspberry Pi running Raspbian

2. Create a virtualenv using the dependencies from requirements.txt

virtualenv coffeeEnv
pip install -r requirements.txt

3. Run the coffee_scale.py script from the virtual environment

./coffeeEnv/bin/python coffee_scale.py 1>/var/log/coffee 2>&1

The main method in this module will loop forever, and will take a reading off the scale once per second. If you use monit you can use the start and stop scripts from the /bin folder. Note, those scripts assume you're running this scripts as root, and that the source code has been checked out from, and a virtual environment exists in the /root directory.

I ran this script as root because of the low risk to our isolated Raspberry Pi environment. If desired, you can chown the ownership of the /dev/usb/hiddev0 device to your standard user, and run this script as that standard user.

Integrations

There is built-in support for initial state dashboarding. Supply the INITIAL_STATE_ACCESS_KEY environment variable with your initial state key, and this code will send weights to your initial state account.

File List

• coffe_scale.py - Main entry point for reading data from the scale
• 51-user-scale.rules - udev file to be placed at /etc/udev/rules.d to automatically map /dev/usb/hiddev0 to /dev/dymo_scale
• usescale.py - Reference python implementation lifted from here. Included here as a reference in case it is needed in the future for future scale reverse engineering.

References

Initial inspiration for this repository was pulled from this C repo. The scales.h file was my first stop in finding a scale that would be supported via USB and easily read with either C or Python code.