I’m after some more EmonTH type units, specifically with 868MHz radios in them.
I’m trying to expand my very old system from 2012 which is still going strong, without ripping it out and starting again, which would be a shame as it’s behaved very reliably for well over a decade.
Anything considered, even DIY versions of the units.
Thanks in advance!
If you can’t get any more 868MHz EmonTHs then as an alternative ….
Assuming your system sends its 868MHz data to an emonPi, then you could perhaps try plugging in a
JeeLink RFM69CW to USB Transceiver 433Mhz Standard (RF encryption)
to a USB port on the emonPi. I think this should hopefully(!) allow your emonPi to receive 433Mhz LPL data from new EmonTHs and emonTxs as well as your present 868MHz data. see
from above:
The JeeLink is a fully assembled and ready-to-use USB-type “stick” which plugs directly into a PC, Mac or USB hub. It contains Atmel’s ATmega328p AVR microprocessor, HopeRF’s 433Mhz RFM69CW wireless radio module and a FT232R USB interface chip.
Useful to adding RF capability to a Raspberry Pi / emonHP to receive data from emonTx or emonTH.
We can preload the RFM2Pi firmware which has been re-compiled for the JeeLink with either the JeeLib Classic (compatibility) firmware or the new Low Power Labs firmware.
To use the JeeLink with emonHub, use the following config:
[[jeelink]]
Type = EmonHubOEMInterfacer
[[[init_settings]]]
com_port = /dev/ttyUSB0
com_baud = 38400
[[[runtimesettings]]]
pubchannels = ToEmonCMS,
subchannels = ToRFM12,
nodename = RF
I haven’t done exactly this myself, but I did have an emonPi running 433MHz LPL format with a USB 433MHz Jeelink running Jeelabs format so I could receive both formats while I was converting my units one by one from Jeelib format to LPL format; it worked ok.
Yup, a jeelink is a good solution.
You could desolder a 433Mhz RFM69CW and then re-solder a 867Mhz version:
We’ve standardised on 433Mh in 2014, so it’s unlikely there will be many 868Mhz around any more:
Is that realistic without the proper workstation, or heating the whole emonTH to reflow temperature?
I’ve done it in the past, but it’s not easy. Would not recommend.
I certainly wouldn’t recommend it either. There is a major risk of damaging the main p.c.b. I did consider making a wide U-shaped soldering iron bit to melt the solder on all 16 pads at the same time, it would need a gas blowtorch to get it hot and I wouldn’t promise success even then.
What Robin Emley did on his Mk2 V Router worked well for home construction, but wouldn’t suit a production run of more than a few. He fixed the RFM with double-sided tape and set the pads a distance away, and spanned the gap with wire links. It made it very easy to change the RFM.
They are available commercially.
For illustrative purposes only:
That said, finding the correct one might be like looking for chicken lips. 
Yes, something very much like that, of course with dimensions to suit. I’ve never had any success with finding a hen with teeth either 
