I purchased a few nanode kits, and am interested in adding an emontx to start monitoring my energy usage.
My electricity network has 9 groups, that I all want to monitor using CT sensors. From reading this site, I assume I need:
- 3x emontx (2.0)
- 1x nanode (question: do I need one nanode per emontx, or can I use a single nanode as a central hub?)
- 9x CT sensor
- sensors for gas, water
Would this be the best setup for 9 power groups? Also, I have two RFMB12 modules that are 868 Mhz. I'd love to avoid buying new 433 Mhz ones. Can I convert the emontx kit to 868 Mhz somehow?
Thanks in advance,
Hi Robert ,
Yes you correct you would need 3 x emonTx's and 9 CT's. One Nanode can receive data from multiple emonTx's. We have written some Nanode firmware for this: https://github.com/openenergymonitor/NanodeRF/tree/master/nanodeRF_recieve_multiple_emontx
Each emonTx would have to be on the same network group and have a different node ID. The Nanode then extracts the node ID from the RFM12 packet to separate the signals. For this to work you will have to use the line
rf12_sendStart(rf12_hdr, &emontx, sizeof emontx, RADIO_SYNC_MODE); - with hdr info
to send data from the emonTx. Its currently commented out in the emonTx firmware. The line
rf12_sendStart(0, &emontx, sizeof emontx);
uses slightly less power by not sending the node ID if its not needed.
Yes the emonTx can use the 868Mhz modules. You will need to change the line
#define freq RF12_433MHZ
to 868Mhz. We use 433Mhz since thats whats available in the UK and they work worldwide. You will also need a JeeLabs RFM12 breakout board for the Nanode to receive the data. This will also need a 868mhz module. We can supply the PCB for this.
Good luck, Glyn.
Sounds good! I already have the Jeelabs PCBs+modules, so I'll just need a few more for the emonTXes. I'll ponder the GBP 180 for a while, and will contact you as soon as I'll get myself over that hurdle :)
Why not build up slowly, get one unit and get that up an running and talking to your Nanode before committing to a big order.
Makes sense. I'll contact you about pricing + shipping. Thanks again for your input :)
Great thought!!!! Looking forward for the implemention of the kit.
I tried to convert the emontx kit and after some time i succeed... Now I am very pleased with the results..
I'm also currently trying to get a second emontx talking to the Nanode but when I put in line
then it says RADIO_SYNC_MODE was not declared in this scope. I realise there is something I've missed, but cannot figure what it is?
What I have done is taken the standard emontx program and commented out all power lines and put in lines to read 3 x DS18B20 temp sensors which all works fine when I leave the node ID as 10 (the other/original emontx not powered up). This prints correctly to serial and also displays correctly on emoncms.
When I change the emontx node ID to 11 and also the NanodeRF to look for 11 then it also works.
But when I try to look for both emontx's on nodes 10 (original with 2 CT's and AC/AC adaptor etc.) and 11 (new with only 3 x DS18B20's) then it all goes wrong with the Nanode repeatedly printing the DHCP Status : 1, and only a partial IP address.
Also this link is no longer there - https://github.com/openenergymonitor/NanodeRF/tree/master/nanodeRF_recieve_multiple_emontx
Can anyone help with any pointers on getting both my emonTx's communicating with the NanodeRF at the same time?
It looks like the link has been moved to https://github.com/openenergymonitor/NanodeRF_ethershield
I am only using 2 emonTX's to connect to the nanode. I haven't looked at the code yet, I'll let you know how I go.
Open-source tools for energy monitoring and analysis. This project uses the GNU General Public Licence