This library is meant to control the USB-RLY02 product from Devantech, using its serial communication.
Create a virutal environment and install the dependencies.
$ python3 -m venv .venv
$ source ./venv/bin/activate
# verify
$ which python3
$ python3 -m pip install -r requirements.txtUse the setup.py to install as a development
$ python3 setup.py developSet up the arguments
args = {
"device": "/dev/ttyACM0",
"bauds": 115200,
}Instanciate the class.
lr = LibRelay02(args["device"], int(args["bauds"]))If setup the instance succeed, you can directly call the unthreaded APIs
if lr.setup():
print(f"[I]: Version {lr.version()}")
print(f"[I]: Version {lr.status()}")
lr.all_on()
lr.all_off()
lr.one_on()
lr.one_off()
lr.two_on()
lr.two_off()We use Queues to send commands to the class and retrieve the responses from the serial communication.
The command format is the following :
- A dictionnary with the fields "action" and "query".
class APIAction(Enum):
"""
List of action to specify when dealing with the Queue
SET_STATE: set the state of the relay
QUERY: get info from the relay
"""
UNKNOWN = 0
SET_STATE = 1
QUERY = 2An action is to either set the contactor states or query information.
{ "action": APIAction.SET_STATE.name, "content": RelayStates.ALL_ON.name }
{ "action": APIAction.QUERY.name, "content": RelayQueries.VERSION.name }Here are the enum forthe queries : a relay state or information query.
class RelayStates(Enum):
"""
Values to send to the relay to actually set the state
"""
ALL_ON = 100
ALL_OFF = 110
ONE_ON = 101
ONE_OFF = 111
TWO_ON = 102
TWO_OFF = 112
class RelayQueries(Enum):
"""
Values to send to the relay to get info
"""
VERSION = 90
STATUS = 91Here is an example :
lr = LibRelay02(args["device"], int(args["bauds"]))
q, r = Queue(), Queue()
if lr.setup():
lr.set_input_queue(q)
lr.set_output_queue(r)
lr.start()
q.put({"action": APIAction.QUERY.name, "content": RelayQueries.VERSION.name})
print(r.get())
q.put({"action": APIAction.SET_STATE.name, "content": RelayStates.ALL_ON.name})
print(r.get())Just use pip.
$ python3 -m pip uninstall librelay