My EmonTx is unstable


About once a week now, my EmonTx stops sending data to EmonPi and needs to be restarted. Both AC and 5v power is connected.
It has four CTs attached and the incidence has increased in the last few months to the point that it’s really inconvenient.
When this happens, the attached EmonESP is still accessible over the network, it just has no data to send.

I’d be very grateful for any troubleshooting advice to trace the issue. I’m not sure where to start or even how to find out what firmware version it is running.

The hardware is v3.4.1 Mar 2015.

Could it be related to overheating or some other factor?

Thanks is advance,

Almost certainly not the TX but the ESP. Do a search on the forum re the ESP module.

The ESP is on v2.3.0. Is a firmware update likely to help?

Not sure - as I said look at other threads I think it will give you the answer.

I know the ESP modules can be quite flaky, but it sounds to me like it is the TX.
The OP mentions he can still access the ESP, so that would indicate the TCP stack is still
working when the data “goes away.” I’d think the ESP would go non-responsive if it were the cause. That seems to be what most users report. i.e no network access.

But, stranger things have been known to happen. :wink:

That is quite common. If the ESP -> TX data line is connected (which it used to be) the older firmware sent ‘data’ that causes the TX to stop.

Read the other ESP threads - it is all there.

I’m still betting on the ESP rather than the TX.

I was thinking that, but if the emonTx software dates from March 2015, it predates by a long way anything with serial input as a means of calibration.

I’ve been folowing the threads you reference, but what makes it weird is his hardware is almost
5 years old. Seems like it would have gone belly up a long time ago.

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Intermittent. Getting more frequent. 5 years old? I’m thinking “Dry Joint”. Especially if restarting involves the slightest movement, which is just enough to get it going again for a few days.


Interesting theory. I’ll open it up again and go over the board for dry joints.
Thanks for the input guys. I’ll let you know how it goes.

And loose screw terminals? In fact, every connector is worth looking at.

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Meanwhile, @borpin waits patiently for me to admit that he probably is right!

We’ll see. :grinning:

Is this ESP header arrangement what you mean by the TX line being disconnected Brian?

I don’t have an ESP8266, but I understand from Gwil that all the “Shop” versions have the Tx pin cut off, which yours appears to have. The problem is when a non-Shop ESP is connected and the software with the “On-line” RF configuration (an later calibration) is connected. Then, random characters emitted by the ESP reconfigure the emonTx.

Note a very big problem that continues to confuse everyone: Tx and Rx are swapped on the emonTx pcb, so as I’ve written so many times here, the emonTx is sending data on the pin labelled “Rx”, and it’s looking for data coming in on the pin labelled “Tx”. That’s contrary to convention (unless the emonTx is a modem!)

Is that the right way up?

Is ground left or right? If right, both TX & RX are connected.

It’s not plugged in. It’s leaning on the Aerial socket. You’re looking at the bottom of the emonTx pcb, and the bottom of the ESP module. So GND is on the left in both cases, even though it’s off the picture for the emonTx.

So in Colin’s photo, the pin that IS connected (4th from the left) goes across to the 5th from the left, which is the one labelled “Rx” on the emonTx but is the one it sends on.

(If you remember the very first information published about the ESP, the photo showed the Tx & Rx pins twisted around each other (but not touching) to make the crossover Tx→Rx & Rx→Tx (in real terms - not labelled pins :nauseated_face:)

This I think is a later picture: Using the EmonTx v3 with the ESP8266 Huzzah WIFI module

Colin’s appears to be OK, even if the emonTx has the later software that does accept serial input.


A brief update. I reflowed all the joints on the back of the TX board at lunchtime yesterday and it’s been running fine overnight. I’ll update again in a few days. Thanks for all your input.

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Nothing for a week suggests all is well - or am I tempting fate?

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FWIW, one of my emonTx just died for no apparent reason a couple of weeks ago (it’s a couple of years old). Power-cycling brought it back again. I’ve no idea what the issue was.

No ESP here (except on my UEFI-based computers of course, but I suspect that is a different ESP :slight_smile:

Sadly, I’m afraid you are. There have been two crashes since I last posted. Both required a restart. Most recently I have reconfirmed that the ESP is still online and accessible when data stops flowing but shows “disconnected” in the EmonCMS section. Do you think it may therefore be receiving data from the TX and is unable to pass it on or is the disconnection between the TX and the ESP?