OpenHAB and Arduino COM port

Setup, Configuration and Use Beginners
1

Hello there!

I downloaded and installed OpenHAB 2.0 on windows 10. I also have Arduino connected on COM20, with this sketch:

String cmd = “”;

setup() {

// Open serial communications and wait for port to open:
Serial.begin(115200);

//Serial.println(“Initializing SERIAL…”);

while(!Serial) {
; // wait for serial port to connect. Needed for Leonardo only
}

//Serial.println(“SERIAL initialized”);

delay(1000);

}

loop() {

while(Serial.available() > 0) {

// read the incoming byte:
incomingByte = Serial.read();

cmd += incomingByte;

delay(10);

}

if(cmd != “”) {

Serial.println(cmd);

cmd = "";

}

}

and all works fine from Arduino IDE monitor. I get all the sent commands printed on monitor’s screen.

I’m now learning OpenHAB, and I got some code from Internet (I also followed the tutorial on the site):

default.items:

Group All

String Arduino “Arduino” (All) {serial=“COM20”}

default.sitemap:

sitemap default label=“My first sitemap” {

Text item=Garage_Davide icon="garagedoor" label=""
Switch item=Garage_Davide_Button label="Garage" mappings=[ON="Go!"] icon="energy"

}

default.rules:

rule “Garage Davide”

when

Item Garage_Davide_Button received command

then

sendCommand (Arduino , “1”)

end

OK, it seems to work when I switch the button, but nothing is sent to COM20? This is a part of openhab.log:

[…]
2017-03-22 18:15:34.672 [INFO ] [thome.io.rest.core.item.ItemResource] - Received HTTP POST request at ‘items/Garage_Davide_Button’ for the unknown item ‘Garage_Davide_Button’.

Thanks in advance!

Bye,

Davide

2

There’s the clue. Should you have defined a switch Item for that in your .items file? (the sitemap is just about displaying items)

3

Hi, thanks for your help. I’ll try to fix that, from the log it seems some POST request is received, so something is received when I switch the button. The sendCommand, then, should be fired…or not? I also was thinking that Arduino code is setting 115200 baud, but what about OpenHAB code? Should I set 115200 even there? But, how?

4

Yes, your UI (browser) tries to send/get updated info to/from OpenHab for the missing Item. OH cannot do that and reports an error.

If there is no Item to trigger the rule, there will be no sendCommand.

Seems like a good idea. Unless the bauds match, it will not work. OH cannot guess what you want to do.

5

you should use something like this:

String Arduino "Arduino" (All) {serial="COM20@115200"}
6

Many thanks to all for the help, now I got this working:

default.items:

Group All

String Arduino “Test” { serial=“COM20@115200” }
String Garage_Davide “Garage"
Switch Garage_Davide_Button { tcp=”>[ON:192.168.1.101:8080" }

default.sitemap:

sitemap default label=“My first sitemap” {

Text item=Garage_Davide icon="garagedoor" label=""
Switch item=Garage_Davide_Button label="Garage" mappings=[ON="Go!"] icon="energy"

}

default.rules:

rule “Garage Davide”

when

Item Garage_Davide_Button received command

then

sendCommand (Arduino , “1”)

logInfo(“Garage_Davide_Button”,“sendCommand”)

end

My Arduino got the command. Also I’ve noticed Arduino’s reply in events.log

2 Likes
7

Thanks!