The pico is running micropython and is most easily edited using thonny.
The main.py program runs by default when the pico is powered on. The program runs in a loop and collects the current temperature as well as the status of the relays and outputs this every second. It outputs text in a json format and includes a timestamp in unix epoch time (the pico, unlike a normal raspberry pi, has a real-time clock) as well as copy of the serial input.
The pico will output the status every one second. An example output looks like:
{"time": 1660466250, "relay_1": false, "relay_0": false, "temp_c": 26.875, "serial_input": {}}The pico can accept serial input to control the relays. The input should be given in the following format:
{"relay_0":"on"}Both relays can be specified at once:
{"relay_0":"on", "relay_1": "off"}The relays can also be toggled from their current state:
{"relay_0":"toggle", "relay_1": "toggle"}The result of the given command will be immediately reflected in the output. Here is the reading immediately before the command is received and when the command is received. The relays reflect the state (true) of the serial_input from the same line.
{"time": 1660465915, "relay_1": false, "relay_0": false, "temp_c": 26.3125, "serial_input": {}}
{"time": 1660465916, "relay_1": true, "relay_0": true, "temp_c": 26.3125, "serial_input": {"relay_1": "toggle", "relay_0": "toggle"}}The relays can be controlled directly from the command line by doing an echo directly to the serial input device, shown here as /dev/ttyACM0:
$ echo '{"relay_0":"off", "relay_1":"on"}' > /dev/ttyACM0The output can be monitored in a separate terminal with pyserial-miniterm:
$ pyserial-miniterm /dev/ttyACM0
--- Miniterm on /dev/ttyACM0 9600,8,N,1 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
{"time": 1609459204, "relay_1": false, "relay_0": false, "temp_c": 26.8125, "serial_input": {}}
{"time": 1609459205, "relay_1": false, "relay_0": false, "temp_c": 26.75, "serial_input": {}}
{"time": 1609459206, "relay_1": false, "relay_0": false, "temp_c": 26.8125, "serial_input": {}}
{"time": 1609459207, "relay_1": false, "relay_0": true, "temp_c": 26.8125, "serial_input": {"relay_1": "off", "relay_0": "on"}}
{"time": 1609459208, "relay_1": false, "relay_0": true, "temp_c": 26.8125, "serial_input": {}}
{"time": 1609459209, "relay_1": false, "relay_0": true, "temp_c": 26.8125, "serial_input": {}}
The panoptes-utils serial device and the serializers can be used to easily interact with the device. The SerialDevice will automatically store the most 50 recent readings (this number can be configured).
$ ipython
Python 3.10.5 | packaged by conda-forge | (main, Jun 14 2022, 07:06:46) [GCC 10.3.0]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.4.0 -- An enhanced Interactive Python. Type '?' for help.
In [1]: from panoptes.utils.serial.device import SerialDevice
In [2]: from panoptes.utils.serializers import to_json
In [3]: device = SerialDevice(port='/dev/ttyACM0', name='pico-controller')
2022-08-14 09:07:46.395 | DEBUG | panoptes.utils.serial.device:__init__:183 - SerialDevice for /dev/ttyACM0 created. Connected=True
2022-08-14 09:07:46.395 | DEBUG | panoptes.utils.serial.device:__init__:188 - Applying settings to serial class: {'baudrate': 9600, 'timeout': 1.0, 'write_timeout': 1.0, 'bytesize': 8, 'parity': 'N', 'stopbits': 1, 'xonxoff': False, 'rtscts': False, 'dsrdtr': False}
In [4]: device.readings
Out[4]:
deque(['{"time": 1609459209, "relay_1": false, "relay_0": false, "temp_c": 27.8125, "serial_input": {}}',
'{"time": 1609459210, "relay_1": false, "relay_0": false, "temp_c": 27.875, "serial_input": {}}'])
In [5]: device.write(to_json(dict(relay_1="on")))
In [6]: device.readings
Out[6]:
deque(['{"time": 1609459209, "relay_1": false, "relay_0": false, "temp_c": 27.8125, "serial_input": {}}',
'{"time": 1609459210, "relay_1": false, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459211, "relay_1": false, "relay_0": false, "temp_c": 27.8125, "serial_input": {}}',
'{"time": 1609459212, "relay_1": false, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459213, "relay_1": false, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459214, "relay_1": true, "relay_0": false, "temp_c": 27.875, "serial_input": {"relay_1": "on"}}',
'{"time": 1609459215, "relay_1": true, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459216, "relay_1": true, "relay_0": false, "temp_c": 27.875, "serial_input": {}}'])
In [7]: device.write(to_json(dict(relay_0="toggle", relay_1="toggle")))
In [8]: device.readings
Out[8]:
deque(['{"time": 1609459209, "relay_1": false, "relay_0": false, "temp_c": 27.8125, "serial_input": {}}',
'{"time": 1609459210, "relay_1": false, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459211, "relay_1": false, "relay_0": false, "temp_c": 27.8125, "serial_input": {}}',
'{"time": 1609459212, "relay_1": false, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459213, "relay_1": false, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459214, "relay_1": true, "relay_0": false, "temp_c": 27.875, "serial_input": {"relay_1": "on"}}',
'{"time": 1609459215, "relay_1": true, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459216, "relay_1": true, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459217, "relay_1": true, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459218, "relay_1": true, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459219, "relay_1": true, "relay_0": false, "temp_c": 27.8125, "serial_input": {}}',
'{"time": 1609459220, "relay_1": true, "relay_0": false, "temp_c": 27.875, "serial_input": {}}',
'{"time": 1609459221, "relay_1": false, "relay_0": true, "temp_c": 27.875, "serial_input": {"relay_1": "toggle", "relay_0": "toggle"}}',
'{"time": 1609459222, "relay_1": false, "relay_0": true, "temp_c": 27.875, "serial_input": {}}'])