I am using a Sonoff RF bridge flashed with tasmota to capture RF signals from dual code 433MHz window sensors
Sometimes however, the signal isn’t captured; I can’t say it’s always due to distance as sometimes even the sensor closest to the bridge is missed
So sometimes a window is shown as open even if it’s closed or viceversa
Does anybody have a similar problem and does it make sense to have an additional RF Bridge as redundancy to ensure at least one gets the signal?
I suppose that your intention is some kind of alarm system… I don’t know exactly how your sensors work, but window sensors (or any other for alarm systems) should be supervised, as that’s the basic of burglar system. Many (good quality) systems work on two frequencies (433 and 868MHz).
Two receivers…It could help, or it couldn’t - depends on the cause of missed reception - hard to say since, as said, i don’t know how these sensors work. Does sensor sends state only when window position changes or it sends state regularly at certain intervals?
433MHz band is very occupied and consequently very noisy. Loosing a signal now and then is, sadly, quite normal. I have automatic gate on 433MHz and at times i can’t open it further than couple of metres away, but at times gate work from 50+ metres. 868MHz band is better, but…
No, it just sends the signal on state change (there is a signal for opening and a different one for closing)
I just use them to turn off the heating at the moment
Aha… in this case it’s funny that receiver gets wrong information… unless it’s designed so “funky” that it can decode partly-received signal as correct one and simply assumes one of the positions, which i suspect that happens in this case…
I have RF transmitter from Sonoff for D1 dimmer and from i’ve played with it i can say that it behaves “rather strange”: sometimes works ok, sometimes not at all, sometimes with some lag… so it’s pretty much useless from my point of view… i love Sonoff’s wifi modules, but i think that their RF section is a big no-no… i’ve read too many complaints on internet from various users, many report random blinks and power toggles on D1 dimmer, so it’s pretty much essential to cut it off (on PCB). Can’t be much different in RF Bridge, i guess. Supposely it’s wrong choice of receiver chip.
I guess you have HA installation (since you write in HA forum)? I’d do it with HA and esp8266 modul or one of Sonoff’s 230V switches like THIS ONE. It’s supervised (via HA) and better in all ways. If you don’t have HA then even Sonoff’s Ewelink app is pretty usefull.
I think you misunderstood me; when an open window is shown as closed in HA or viceversa, it’s because the bridge didn’t get the signal, so the state in HA doesn’t change
Hi Jacoscar,
I too have an extensive RF433 system in my house. Similar to you i expect. Tasmotised Sonoff RF Bridge & 25 door/window/motion RF sensors.
I too experience the same aparent intermittent missed code in my environment. I say aparent because i actually have not 100% confirmed that it’s the transmitter/receiver that’s having the issue. Perhaps it’s somewhere else in the stack. Could it be wifi comms with the RF bridge or a tasmota glitch or a sensor glitch or an MQTT glitch or HA/python script glitch?
From day 1 of implementing RF sensors (more than 2 years ago now) i figured that RF range and/or interferance could be an issue. I have tried to locate my RF bridge as centrally in my home as i could to give it the best change to succeed. I also tried to place my sensors in positions where they might be less prone to interferance. In my house I tend to think it’s an RF comms issue between the transitter & receiver, but as i say it’s anecdotal evidence so far.
What i can say with some confidence is that a low battery is definately a cause of some intermittent unreliability. I don’t know if it’s a general limitation of these RF sensors or just the ones i purchased, but there is no battery level reporting. So i have had to take notes about when i last replaced the battery & just go about replacing them on a schedule. So far about 1 year is good for me but there are instances when a sensor become unreliable & a battery replacement seems to solve it.
Nowadays i also have an extensive network of Zigbee sensors for temp/humidity/lux/motion & my RF senors are mostly for doors/windows. Zigbee is not without it’s own challenges but range is less of a concern since they build their own mesh.
Oh, before i forget, i wanted to also say that i have thought about a second RF bridge to help with range but i figured that would overly complicate the filtering of the RF codes that might be received & processed by both bridges. I left that in the too hard basket.
Any, sorry for the monologue, don’t think that really helped you much 
Cheers
Nick
So it’s when window is open heating is shut down and vice versa, right?
No-getting the signal is just what i described: disturbance and congestion. Connect headphones to audio output of RF receiver - you’ll hear Sydney opera of transmitters…then there are things, that can make your life bad: in my place electric workers draw a power line for street lighting exactly above my automatic gates (where antenna is). Because of that powerline my range dropped to 2-3m and i’ve had to move my receiver some 10m away from that location to be useable again. Then there are communication lines which can cause disturbance…
As said: on 433MHz there are weather sensors, garage openers, some audio devices, some cheap toys, cheap walkie-talkies…you name it, it’s there. That’s why two way permanently monitored communication is the only 100% proof solution.
Switching to 868MHz would help. But, first: sonoff doesn’t make 868MHz if i’m not mistaken, and second: you’d have to buy all stuff again and in this case wifi module is a better (and cheaper) choice. In your case i would put one wifi moudule as window sensor and second module as heating switch. If you’re up to it you can make it yourself pretty cheap: ESP12 modules are dirty cheap. You put ESPHome into it, connect a window switch to input and you’re done.
BUT… i think (correct me if i’m wrong) that your other (rather big) problem is power supply… currently you run window sensors on battery, so i guess that you don’t have wires for eventual wifi module there, right?
I used a sonoff bridge for a few years now with a bunch of door/window/water sensors scattered around my house. I actually had a second sonoff so I decided to set up a redundant bridge setup since if I happen to get two triggers of window open or door open or water sensor triggered it’s not a big deal. It worked great, HOWEVER, about two or three months ago one of my sonoff bridges died so I ordered two new ones (the new ones are white and the old ones were black).
I flashed one of them with tasmota and replaced the busted one. Then suddenly I started getting a bunch of battery low signals on doors sensors that I had just replaced. I verified that the batteries had over 1.5V on them. When I look at the logs from my two tasmota consoles, I can see discrepancies!!
for example:
From old device:
12:47:06.917 MQT: tele/sonoff-bridge-a/RESULT = {"Time":"2022-09-30T12:47:06","RfReceived":{"Sync":14150,"Low":500,"High":1370,"Data":"30060A","RfKey":"None"}}
12:48:07.877 MQT: tele/sonoff-bridge-a/RESULT = {"Time":"2022-09-30T12:48:07","RfReceived":{"Sync":14140,"Low":500,"High":1370,"Data":"30060E","RfKey":"None"}}
17:00:54.535 MQT: tele/sonoff-bridge-a/RESULT = {"Time":"2022-09-30T17:00:54","RfReceived":{"Sync":14090,"Low":480,"High":1400,"Data":"5F2B0A","RfKey":"None"}}
17:00:59.258 MQT: tele/sonoff-bridge-a/RESULT = {"Time":"2022-09-30T17:00:59","RfReceived":{"Sync":14120,"Low":490,"High":1390,"Data":"5F2B0E","RfKey":"None"}}
19:33:49.525 MQT: tele/sonoff-bridge-a/RESULT = {"Time":"2022-09-30T19:33:49","RfReceived":{"Sync":14200,"Low":480,"High":1380,"Data":"332D0E","RfKey":"None"}}
19:47:16.243 MQT: tele/sonoff-bridge-a/RESULT = {"Time":"2022-09-30T19:47:16","RfReceived":{"Sync":14060,"Low":510,"High":1360,"Data":"30060A","RfKey":"None"}}
From new device:
12:47:07.533 MQT: tele/sonoff-bridge-b/RESULT = {"Time":"2022-09-30T12:47:07","RfReceived":{"Sync":27930,"Low":888,"High":2688,"Data":"30060A","RfKey":"None"}}
12:48:08.629 MQT: tele/sonoff-bridge-b/RESULT = {"Time":"2022-09-30T12:48:08","RfReceived":{"Sync":27930,"Low":894,"High":2686,"Data":"30060E","RfKey":"None"}}
17:00:55.022 MQT: tele/sonoff-bridge-b/RESULT = {"Time":"2022-09-30T17:00:55","RfReceived":{"Sync":26794,"Low":982,"High":2622,"Data":"572B08","RfKey":"None"}}
17:00:59.823 MQT: tele/sonoff-bridge-b/RESULT = {"Time":"2022-09-30T17:00:59","RfReceived":{"Sync":26268,"Low":952,"High":2650,"Data":"5F2B06","RfKey":"None"}}
19:33:50.923 MQT: tele/sonoff-bridge-b/RESULT = {"Time":"2022-09-30T19:33:50","RfReceived":{"Sync":26270,"Low":914,"High":2666,"Data":"33250A","RfKey":"None"}}
19:47:17.094 MQT: tele/sonoff-bridge-b/RESULT = {"Time":"2022-09-30T19:47:17","RfReceived":{"Sync":26104,"Low":894,"High":2688,"Data":"30060A","RfKey":"None"}}
You can see that one of them get 572B08 and 572B06 instead of 5F2B0A and 5F2B0E!! Also, the new one shows 33250A instead of 332D0E! Incidentally, the new one is closer to the sensor that it is having problems with. I think these new white ones must not work as well… and be aware of incorrect results being passed in if you happen to get a second sonoff bridge for redundancy.
If I can find the second one I bought, I’m going to program it and see if it’s any better at detecting the signals or if it sucks too…