Openhabian 3 serial binding not sending data pls help

Add-ons Bindings
,
1

Hello,

I’m new to openhab and one of the first things I’m trying to do is send a string from a raspberry pi 4 running openhabian 3 to an arduino using the serial binding. I’ve spent days researching the serial binding and I just cant get it to work.

Here is the serial bridge thing I created:

Bridge serial:serialBridge:sensors [serialPort="/dev/ttyUSB1", baudRate=9600] {
Channels:
Type string : control []
}

and my String item:

String deviceControl {channel=“serial:serialBridge:sensors:control”}

My rule that should be sending a string to the string channel via the deviceControl item when my WL item changes:

rule “blah”
when
Item WL changed
then
var state = WL.getState
sendCommand(deviceControl,“hi\n”)
end

and finally my arduino code:

void setup() {
Serial.begin(9600);
pinMode(13,OUTPUT);
}
void loop() {
if (Serial.available() > 0) {
String data = Serial.readStringUntil(’\n’);
if(data == “hi”)
{
digitalWrite(13,HIGH);
delay(2000);
digitalWrite(13,LOW);
}
}
}

In the serial bindings docs it says if I send a string to the string channel in the serial bridge it will send that data to the serial port, but it wont work.

Can anybody help?

2

Does your rule trigger at all? Check the log to see if your item actually changes state
maybe add a log statement to your rule to read out what gets returned
How are you viewing the state of your item? In the user interface? sitemap?

3

Thank you for the response!!!

the state changes show in my log viewer:

2021-09-01 01:27:34.273 [INFO ] [openhab.event.ItemCommandEvent ] - Item ‘WL’ received command 214,29,89
2021-09-01 01:27:34.279 [INFO ] [openhab.event.ItemStateChangedEvent ] - Item ‘WL’ changed from 173,29,89 to 214,29,89
2021-09-01 01:27:34.360 [INFO ] [openhab.event.ItemCommandEvent ] - Item ‘deviceControl’ received command hi
2021-09-01 01:27:34.363 [INFO ] [penhab.event.ItemStatePredictedEvent] - Item ‘deviceControl’ predicted to become hi

the rule is working and properly sending the command to the item but nothing gets sent through the serial port. I made sure the serial port was working by sending:
echo -e “hi\n”>> /dev ttyUSB1
in the terminal window and it triggered the arduino and was registered in the log as:
2021-09-01 01:30:06.088 [INFO ] [openhab.event.ChannelTriggeredEvent ] - serial:serialBridge:sensors:data triggered PRESSED

4

Is this a rules file or is the rule entered via the OH UI ?
In an other thread one member used the UI and observed that the plug didn’t changed it’s state.
End of the story was that it looked like the UI escaped the \ other than expected but the rule is working fine from a rules file.