I’ve an EmonTx about 14m from an emonPi. There’s 2 walls between them. Until recently I had a good connection over 433MHz. Recently I noticed gaps in the data. Is this likely to be a poor signal, or something else?
The EmonPi has a long black antenna but the EmonTx has a stubby one. Would better antennas help, should I go WiFi or even wired?
Thanks
You need to be a bit more precise.
Are your emonTx and emonPi both working on the same radio frequency, and equipped with the correct radio module and antenna for that frequency? (Pictures of various modules are in “Learn” to help you to identify them, the 433 MHz antenna is approx. 180 mm from the knuckle to the tip, the 868 MHz one is approx. 105 mm from the knuckle to the tip.)
Did the antennas come from The Shop with the emonTx/emonPi, or did you get them from somewhere else?
It does sound as if you have a mix-up somewhere, the real problem is knowing exactly what is wrong. Ideally, you have the module and antenna both “tuned” to the radio frequency you’re operating on., and both ends must be the same. Things do work (of sorts, but inefficiently) when there’s a mix-up.
You could log RSSI to see what it’s reporting.
Many thanks Robert.
Both EmonPi and EmonTx are stock from The Shop. I believe they’re on 433MHz.
I have a 180mm long antenna on the EmonPi, and a short ~50mm antenna on the EmonTx (which also has a 433MHz sticker).
I’m getting -77 from the rssi feed on the Tx - seems low?
Can I get anything else from the rssi log (and how do I access it please?)
Don’t you mean on the Pi? RSSI = Received Signal Strength Indicator. It should be OK at that - just, but it’s not the best.
It’s probably worth moving one or both ends just a little, just in case one is in a ‘dead spot’ where a reflection is partially cancelling the signal.
The same way as any other variable in emonCMS. You need to save it to a feed on the Inputs page, then you can put it on a dashboard, graph it, etc.
1 Like
Here’s an easy method to improve the signal strength (it can be done at both the transmitter as well as the receiver) It may or may not be practical or even possible, depending on your hardware installation.
I’d first consider what has changed. Have any new 433MHz devices been installed nearby?
Completely reboot (remove power) from both devices.
Does the issue continue?
Is there anything in the logs especially the emonhub log?
The only change has been a Mesh wifi system, which uses 5GHz as well as 2.4GHz.
I managed to improve the rssi to better than -70 by moving the emonTx. Much better now - I used to lose data for a few minutes at a time, now it’s just the odd data point, which I can live with.
Having an rssi signal to help reposition the emonTx was really useful, thanks.
2 Likes