Adding second emonTx Shield - no data seen

I have a working emonTx Shield (ID:6) talking to an RPI fitted with an RFM69Pi board and running the SD image ‘emonSD-21Jul21’ from the repository - all working well.

I needed to add monitoring away from the first emonTx Shield so another was assembled and the ID changed to 7 in the Arduino sketch (so it’s unique) . I have also edited both ‘nodes’ sections of the emonhub.conf files (there appear to be two, one in /opt/openenergymonitor/emonhub/conf/ and the other in /etc/emonhub/ - not sure which one is used so edited both) to change the data format for ID7 from stock to replicate ID6 so the data formats should be correct.
They both now look like this: (I’ve had to type this so hopefully it’s right)
nodename = emontxshield
names = power1, power2, power3, power4, vrms
datacode = h
scales = 1,1,1,1,0.01
units = W,W,W,W,V

nodename = emontxshield1
names = power1, power2, power3, power4, vrms
datacode = h
scales = 1,1,1,1,0.01
units = W,W,W,W,V

The inputs are not populated for the ID 7 unit and no data is displayed. A quick check shows that if I disconnect the ID 6 unit and recode the emonTx Shield from ID 7 to ID 6 it starts working as ID6.
Now I’m not really a Linux person and it looks like a config problem as I can see the hardware working when the IDs are changed but I have not been able to sort out why - any help much appreciated - Oh and sorry for the long post.

Are you saying that you have the Shield with no inputs, but working and transmitting as Node 6, yet you see data?

Well, I would expect that you would - but it will be electrical “noise” picked up by the inputs and converted to look like a power - but I’d be surprised to see more than a few watts, though depending on the calibration you’ve set.

The reason you see the noise, and not a solid zero value, is because the input socket - when it is fitted, grounds the ADC input when there’s no plug inserted, and that is sensed by emonLibCM and it forces the output power and current values to exactly zero.

The easy way to edit the file is via emonCMS and your web browser: Setup → Emonhub →Edit config. (And you can copy &paste from there :wink:)

Correct. It’s essential that each Node in your Group has an unique ID, otherwise the data gets mixed up in emonCMS.

Hi Robert,
Thanks for replying. I probably haven’t made it clear… The new node 7 emonTx Shield does have inputs but they are not shown in emonCMS - emonCMS just doesn’t see node 7 and doesn’t populate the inputs field with powers 1-4 and voltage.
So what I’m saying is that emonCMS doesn’t display anything from node 7- it’s perfectly happy with node 6 but it just doesn’t recognise node 7. Hope that makes it a bit clearer.

Thanks for the editing tip - I’ll give that a go.

So a little more information: I see the following in the log:
2022-05-06 09:59:16,440 DEBUG RFM2Pi 499 NEW FRAME : OK 7 34 0 24 0 32 0 83 0 150 3 (-27)
2022-05-06 09:59:16,441 WARNING RFM2Pi 499 RX data length: 10 is not valid for datacodes h
2022-05-06 09:59:18,267 DEBUG RFM2Pi 500 NEW FRAME : OK 6 46 0 0 0 0 0 0 0 228 93 (-54)
2022-05-06 09:59:18,269 DEBUG RFM2Pi 500 Timestamp : 1651827558.267069
2022-05-06 09:59:18,269 DEBUG RFM2Pi 500 From Node : 6
2022-05-06 09:59:18,270 DEBUG RFM2Pi 500 Values : [46, 0, 0, 0, 240.36]
2022-05-06 09:59:18,271 DEBUG RFM2Pi 500 RSSI : -54

It looks like the data is being received from node 7 but is rejected - Does this help in identifying the problem?

So it looks like I can’t type - I managed to datacodes rather than datacode for the node 7 config. So all is now working. Thanks for the help. (And I double checked the config changes!)


FFT :slightly_smiling_face: