I have just installed a 1m 433mhz antenna, and looking for something to put on the end of it.
Currently, I have a CC1101 and ESP32 on the end running on esphome, but its a little complicated and restricted to what I can do with it, such as sniff for codes etc.
What is a good option of software or platform to run for use with field devices using 433mhz?
Thanks
Thank you,
What is the best one to flash? Is there an option that support transmitting as well as receiving?
There are quite a few targets to choose from.
433MHz requires antenna length 17.3cm (quarter wafe), or double of that (half wave), any longer wonât make any difference. Length is important! Itâs not ljust any piece of wireâ.
Longer antennas can be used, but they must be exact lentgh, however they can be even worse than half-wave, since signal must travel longer distances and itâs attenuated.
Some reading
It was a purchased 433mhz antenna.
Well, youâll see the effect⌠pretty much all my efforts with longer antennas went south⌠note that with longer antenna you also catch more unwanted signals. Just as example with my BT: external antenna on esp32 actually made things worse than pcb one⌠similar was on my router and 6dBi antennas vs original ones.
But back to the topic: I donât think that thereâs such thing as universal âcatch them allâ receiverâŚ
Yes, but I do need range, I need to receive ~300m range.
So how do I learn new device codes? I really am very fresh when it comes to RF
Well⌠i think that you started wrong way with buying an antennaâŚfirst you decide what you need (which device, what to control). Then do a search on the internet for available devices. When you find some, do a search IF any of those can connect to HA. When you find which one does connect to HA, then do a search for suitable receiver and buy it.
If you only need two way communication then i think youâll hardly find a more universal and versatile solution as esphome⌠you just choose one of suppported protocols and youâre good.
Regarding increasing range of a signal: directional antenna is the way to go. 433MHz has very low output power, and band is veeeery busy, with tons of similar devices (weather stations, remote controle, gate openers, you name it, itâs thereâŚ), so onmi antenna will be quickly overloaded with strong unwanted signals (from your neighbourâs devices)⌠only way youâll get a reliable connection over Äžong distance is if youâre alone, without near neighbours, factories⌠i installed 433MHz remotes (automatic gates) for over 12 years, i know all problems when range was 1m or less because of near noise⌠sometimes 2cm of wire was better than original antennađ
Perhaps a better option in that case is to use 866MHz, less disturbances, but itâs more directional.
Oh, yes WIFI with a good directional antenna. This is a DIY 2.4ghz Biquad that I use with Tasmota for wifi and Bluetooth. Even picks up neighbours toothbrush and sky Q remotes though a few solid walls. Would work well with Esphome just as easy.
If you need to get a signal from 300m it is better to boost the signal on the device so the broadcast is stronger than making the receiver so good it picks up crap from the whole neighborhood.
To pick up my mailbox door sensor I disconnected the internal antenna of a rf433 door sensor and added a half wave length of wire. Works a treat! About 100ft across the yard below grade and thru a couple of house walls.
Post a pic of that if you can.
I have a pic around, but not of the inside. All you see is a sensor with a wire hanging out.
I just cut a half wave wire (could be a quarter, donât remember, itâs been since 2019) for 433, cut the pwb on the device after the protection cap or whatever it was that bridged the signal to the original antenna, and soldered the wire there. Then stretched the wire straight out thru the mailbox so it hangs underneath into open air as much as it could.
Length of the antenna being a quarter, half, or full wave is important if you are transmitting to keep the SWR down and you donât blow the transmitter outputs.
This sensor provides us the obligatory AOL voice, 'Youâve got mail!".
I got a min VNA for the receiver side to get the best SWR. Got best SWR with J pole but farfield pattern didnât suite. Ended up using ground plane antenna.
Same exact sensor as I usedâŚ
With the mailbox as the weather shelter and pushing thru the bottom, it has lasted about 5yrs so far, knock on the mailbox postâŚ
Do you also watch for the battery is dead code?
Low Battery Code for GS-WDS07 2 Code (4 code) Door Sensor | What Are We Fixing Today?.
They were the cheapest I could find. Yes use telegram to inform me if mail or if battery low. Only time it fired of a low battery was when it got soaked and destroyed the unit. I measured the cell and it was down to 0.6V so I reckon it has a Joule thief built in.
It gets to a point and when it triggers, it spams that code out until there is nothing left of the battery.
OK, that makes more sense. 
It seems that the replies are taking a tangent. It would help if we knew what data you are looking at sending/receiving. There may already be an off-the-shelf solution.
The CC1101 is a transceiver chip from Texas Instruments. Are you using a development board? How did you interface it with the ESP? I would be curious to see the ESPHome yaml file.
A 1m base-loaded antenna is not unusual but without knowing what data you are trying to communicate, antenna selection is a bit premature.
Thanks for the reply,
Im looking for a simple letter box transmitter. Its about 300m range but no quite LOS.
I have connected the CC1101 to an ESP32 currently running with esphome and using this library for esphome.
