D20S-LB Temp Reading

gmalsack · January 17, 2025, 11:07am

Hello All -

I have the v4 server up and running. I have my gateway (SenseCAP M2-US915) connected and sending packets (shows online in Chirpstack). I also have my Dragino D20S-LB connected and showing online.

I can see the JoinRequest and JoinAccept packets in LoRaWAN Frames. I can see join, status, and up packets in Events. However, I’m not seeing the temperature field in the events. For the status packet I can see the battery level, which is nice. But I can’t seem to find where the temperature reading is showing up.

I’m thinking I also need some help setting up the device profile so the measurements for temperature and battery status show up under the device metrics page. So far, nothing is showing up there.

Thanks everyone!
Greg

sp193 · January 17, 2025, 11:31am

The lack of temperature data is likely linked to the codec script you installed (or the lack of one) in Chirpstack, to decode the data.

I’ve never used the dashboard functionality of Chirpstack, so I cannot comment on that part.

Liam_Philipp · January 17, 2025, 2:10pm

As @sp193 said you definitely are missing a codec, if you look at the “up” events for the device there is a field “data:”, if you have a codec uploaded this will get decoded into a JSON string labeled “object:” containing your device readings, temperature etc…

You can add a codec to your device in the device profile. Once you have that, Chirpstack will begin autodetecting the device readings, and you can select what to graph on the metrics page by configuring the “measurements” page of a device profile.

gmalsack · January 17, 2025, 4:03pm

Here’s what I have loaded for my codec on the device profile. I followed this page from Dragino for adding the device to my Chirpstack system: Notes for ChirpStack - DRAGINO

Liam_Philipp · January 17, 2025, 4:30pm

Lol, everything in that codec is commented out. That is just an outline.

Try this one:

github.com

dragino/dragino-end-node-decoder/blob/main/D20-LB&D20S-LB&D22-LB&D23-LB/D23-LB_v1.3_ChirpstackV4_decode.txt

function decodeUplink(input) {
        return { 
            data: Decode(input.fPort, input.bytes, input.variables)
        };   
}
function datalog(i,bytes){
  var aa= parseFloat(((bytes[0+i]<<24>>16 | bytes[1+i])/10).toFixed(1));
  var bb= parseFloat(((bytes[2+i]<<24>>16 | bytes[3+i])/10).toFixed(1));
  var cc= parseFloat(((bytes[4+i]<<24>>16 | bytes[5+i])/10).toFixed(1));
  var dd= (bytes[6+i]&0x02) ? "High":"Low";
  var ee= (bytes[6+i]&0x01) ? "True":"False";
  var ff= getMyDate((bytes[7+i]<<24 | bytes[8+i]<<16 | bytes[9+i]<<8 | bytes[10+i]).toString(10));
  var string='['+aa+','+bb+','+cc+','+dd+','+ee+','+ff+']'+',';  
  
  return string;
}

function getzf(c_num){ 
  if(parseInt(c_num) < 10)
    c_num = '0' + c_num;

This file has been truncated. show original

gmalsack · January 17, 2025, 4:47pm

Thank you guys for the help. I’ll update the profile with the codec like @Liam_Philipp suggested. Man there is a serious learning curve with this stuff.

Liam_Philipp · January 17, 2025, 5:05pm

Definitely takes some learning, but that’s why there are businesses that can sell the whole package at high prices. If you want it free you need to understand it.

Let me know if you run into any issues with that codec, they can be finicky at times as their standardization is not mainstream yet, but Dragino typically does a good job conforming to each platform.