This library provides an interface from the various Raspberry Pi models for burn-in related activities.
- Install required packages with:
pip3 install --user -r ./requirements.txt - If you have
nixwith flake support installed:nix develop
Note: All scripts in bin assumes you run them in the bin folder.
Continuity checker for the backplane testing.
Invoke with:
cd bin
python3 .Continuity.py
Ctrl-Cto quitjat any time to select another pigtail reference map
ThermSensor.py is a script that reads the output files made by the DS18B20
thermometers and runs a multithreaded process with each thread dedicated to
reading and outputting the data values from one thermometer. Written by Jorge
Ramirez, improvements by Yipeng Sun.
For Raspbian, in the raspberry pi's /boot/config.txt, add the following line:
dtoverlay=w1-gpio,pullup=1
For NixOS, it should already be configured.
The thermistors are wired in parallel by connecting their GND to the VDD pins, and then both to shared ground (Pin 6). The DQ pin carries the data signal into the 1-Wire (aka BCM4 or Pin7) interface. A pulldown resistor is included by connecting the data line to the 3.3v pin (pin 1) as required by the 1-wire interface.
Our lab has streamlined the process of having several dozen thermistors. Each thermistor has the GND pin wrapped around the VDD pin and soldered and all three pins are covered in gel for rigidity. A breakout board was produced with one rail for each thermistor's GND connection, and one rail for each thermistor's data line. Both rails have a wire that allow connection to their corresponding pin (GND -> pin 6, Data -> pin 7) and a 4.7k resistor was soldered onto the data rail with a wire to connect to the 3.3v pin (pin 1).
On our setup, the blue wire corresponds to the data line, the red wire is the pulldown resistor's 3.3v connection, and the black wire is ground.
The ThermSensor.py script will automatically loop and output the temperature
values for every connected thermistor. Run the script with an integer value
to specify the delay between each readout in seconds:
cd bin
python3 ./ThermSensor.py 4
WaterAlarm.py is a script that uses the LS2600 leak sensor in order to monitor
for leaks. If the LS2600 has both contacts in water, the sensor will close the
circuit and then the script will sense the High and track for how long in the
variable 'leak counter'.
Written by Jorge Ramirez, improvements by Yipeng Sun.
USB relay control for Van Ooijen Technische Informatica. Currently only APIs
are implemented, as they have not been wrapped into worker classes that can be
used directly in the burn-in system.
With Jorge Ramirez's schematic, valves control functionality has been confirmed.
Copy the udev rule in udev_rules/50-usb-relay-dct-tech.rules under
/etc/udev/rules.d/ directory, so that everyone (not just root user) has
read/write access to this type of USB relays.
The CP100 Rain Bird Solenoid Valve is connected to the NO (normally open) terminal of the USB Relay so that water will only flow when the Relay turns on and the switch is flipped. Tests showed that the reverse-current created by the solenoid's voltage spike was enough to damage the relay and force it to reset. A 60V 5.5A diode was included in the circuit to allow a back channel for the reverse-current to dissipate.
Multiple valves can be connected, each valve can share the common connection to the + terminal of the power supply, however each valve requires its own diode and NO relay terminal.
To initialize the script, run the command:
python -i ./rpi/burnin/RelayAPI.py
Enter any of the commands below to utilize the APIs.
To list all USB relays that are connected to the computer, use:
>>> p = get_all_device_paths()
[b'0001:0013:00']
To read channel states (currently only support 2 channel relays):
>>> get_relay_state(p[0])
{'CH1': 'OFF', 'CH2': 'OFF'}
Each channel can be turned on/off:
>>> set_relay_state(p[0], 1, ON)
>>> set_relay_state(p[0], 2, OFF)
To test, hook up a valve as shown above. Then call the test_relay(t) method,
where t is the number of seconds between each ON/OFF switch:
>>> test_relay(12)
which will initiate a loop where there is a 12 second pause between ON/OFF switches. Use Ctrl+C to exit.