Contact tracing via smartphone apps has been widely touted as an important way to control and limit the spread of the COVID-19 epidemic. However, basing contact-tracing on phone apps has several limitations. Here are instructions for constructing a contact tracing device prototype with a Raspberry Pi Zero-W. The constructed device is compatible with the Apple/Google Bluetooth contact tracing specification. It runs the Epidose software, which is based on the DP3T "unlinkable" design.
Assemble the following materials:
The objective of this construction is to provide the Raspberry Pi with a switch to authorize the contact upload and a LED to indicate that a user is at risk. The circuit diagram above shows this setup.
Solder one end of the resistor (it doesn't matter which) to the LED's cathode (the shorter of the LED's two wires) to obtain a 17mm long connection. The connected assembly should be able to fit in pins 20 and 40 of the Raspberry Pi.
Cut a 17mm length from the smallest heat-shrink tube that can fit around the resistor, and slide it to cover the entire LED-resistor connection. Heat it to shrink.
sudo venv/bin/python epidose/device/device_io.py --test. This allows you to toggle the LED by pressing the button. Press Control-C and then press the button to terminate the program.
Last modified: Wednesday, May 20, 2020 9:50 pm
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