I installed a system back in Jan 2014 consisting of an emonTX V3, RFMPi 12 V2, emonGLCD all at 868MHz and using a RPi2 and dongle that I already had (I still haven’t got around to building the emonGLCD), I added an emonTH for the garage/workshop nearly 2 years later. It took a bit getting my head around it all but it has been running reliably until I started tinkering yesterday. This was prompted by my son getting an electric car and having a charge point for it fitted yesterday. I know I can simply add another CT to monitor the power usage for the EV charger which is a branch of the meter on the supply. However I thought of going over to the emonPI as it looks a more elegant solution to my lash up. I like the advantage of the LCD on the front even though I think I would loose the chance of using the emonGLCD. Just a few questions before I put an order in. As everything is 868MHz and it seems the emonPI is 433MHz can this be changed to 868MHz or is it easier to swap everything to 433MHz.
I suppose the emonTH would be the only thing needing the frequency change as the emonTX would become redundant unless I re-purposed it elsewhere.
Another question. I believe the emonPI is fitted with a RPi 3. Is this the new 3 B model with faster processor etc. and is the wifi range restricted as it is encased in an aluminium case.
How many CT’s are you currently using with the emonTx?
The emonPi only has 2 CT’s
You can still use the emonGLCD with the current OEM images.
Adding a CT to your existing setup would be the easiest route if you have a spare channel on the emonTx.
Changing to an emonPi will also involve backing up and restoring your historic data unless you are not fussed about loosing it.
It isn’t really feasible to change the frequency of a device, in some instances it can be done, but the range would be a small fraction of what it should be, in some cases the devices would need to be within a meter (or less) of each other.
The emonTH v2’s are more accurate and the batteries last longer, so trying to convert one might not be worth doing if you are upgrading.
One of the emonpi end plates is now perspex to allow the on-board wifi to work.
Thank’s for the reply Paul. I have just posted a second query regarding emoncms.org and this upgrade I am contemplating here.. I decided to try a re-install with a new SD card image after a failed update.
At the moment I only have 1 CT though will be getting a second to monitor the feed to sons newly fitted EV charger. I agree adding another CT to the existing emonTX is probably the easiest and cheapest route. I suppose I just liked the look of the emonPi and would find the LCD display useful. I am not sure why 868MHz was suggested at the time but it seems 433MHz is the default and most popular. I would have thought it would also have better range due to the lower frequency. My emonTH is v1 also so I am happy to replace it with a v2. So would standardising on 433MHz be the better option if I do go for the emonPi. I can’t envisage needing more than the 2 CT’s.
I thought emonGLCD got it’s data directly from the emonTX. Therefore am I right in thinking if I replace the current RPi/emonTX setup with an emonPi then I wouldn’t be able to use the emonGLCD as the emonPi doesn’t retransmit data.
Yes that is the current status, i would like to see emonhub transmitting data to the emonGLCD, it shouldn’t be too complex to achieve, but currently it doesn’t, so yes, the jump to the emonpi would effectively exclude the emonGLCD except for the time/clock.