Initial Setup with ESPWifi

Hi everyone,

I recently received my emonTx and wifi module but I’m having problems getting setup.

  • I have the emonTx 3
  • powered by both the ACAC adapter and USB power supply
  • Jumper 20 pulled.
  • CT1 plugged in and clamped.
  • Connected to the wifi module and directed it to my Wifi network.
  • I get information about the device starting up, seeing the power and CT but no data coming through afterwards.

I’ve rebooted both the esp module and emonTX a few time but to no avail. Am I missing something simple? maybe there’s another step to getting the emonTX to print out data to the serial?

I also noticed the search for firmware updates was missing, but that may be unrelated

Welcome, James, to the OEM forum.

There is indeed. You must turn off the ISM band radio, and that automatically turns on the serial data in the correct format.
Look at the instructions your emonTx prints to serial at start-up. The bit you’re looking for is:

  s         - save config to EEPROM
  v         - show firmware version
  w<x>      - turn RFM Wireless data on or off:
            - x = 0 for OFF, x = 1 for ON, x = 2 for ON with whitening
  x         - exit and continue

So, as it starts up, do +++ to enter Config Mode, type w0 (numeral zero), then s to save. x to continue.

You MUST NOT “clamp” the c.t. onto the cable. Doing so risks fracturing the very brittle ferrite core, and if that happens, you c.t. becomes useless. The springs that are part of the case moulding are perfectly adequate, and it doesn’t make a discernible difference if the c.t. doesn’t sit absolutely square and centred on the cable.

@TrystanLea @glyn.hudson Is an emonTX unit sold with an emonESP, configured with the serial enabled?

I thought they were supposed to be…

@James_Hannon - did you get both from the OEM Shop - on the same order?

Yep, order 23023

I also wasn’t getting ‘+++ config’ option, just straight into the AC/CT debug information.

Unless I’ve misunderstood the question…
Given that’s how the data gets from the emonTx to the ESP8266 module, it has to be.


Yes, but the default is ISM Radio, with Serial disabled. The Shop (as I understand it) should set the default to Radio off, Serial on.

There’s no way for the emonTx sketch to test for the presence of an ESP8266, because only the outgoing data is connected - because the ESP8266 sends unwanted data out that screws up the calibration of the emonTx the incoming data to the emonTx has been cut off. So it has to be done manually.

What puzzles me is James reports no “+++” to enter config. mode.

@James_Hannon - that’s sent by the emonTx on the serial port as it starts up. Were you looking at that with a programmer? If you do have a programmer, you can disconnect the ESP and set up the emonTx. Otherwise, I suggest you email the shop, and see what they say.

Makes sense.
After all, why would one even buy the ESP option if one didn’t intend on using it, right?
(of course things can, and often do, change between time of order and time of delivery)

That was indeed with a programmer, I popped over to the office to go grab it. I was thinking old firmware as the output didn’t seem to match the serial prints in the .ino file … on github/master.

I was thinking the wifi module was going to make life simpler, save me having to port the emonhub code over to docker (I already have too many RPi’s running in the house to run another dedicated device) and just write to a emoncms running locally via docker-compose.

I’ll give reflashing the hardware using the flash tool a go and if no avail get in touch with sales.

Cheers for your help guys.

Hello @James_Hannon, first sorry that we missed configuring the EmonTx to enable serial and disable the RFM radio.

This is a bit strange, it may be because you opened the serial window after it had started printing to serial… Could you try connecting the programmer again and then resetting the EmonTx whilst the programmer is connected with the reset button on the side of the unit?

The steps to enable serial printing are:

+++ enter

w0 turns the radio off, s saves the configuration to EEPROM.