I’ve been trying to find a nice temperature sensor I can put outside and have it be reliable for many years. I’m on my third replacement of cheap 433MHz temperature sensors from weather stations, and they start reading weird after a year or two.
I do like the low power aspect of 433MHz, two AA batteries last 2 years with these things. But the way they’re built is… a circuit board with a NTC thermistor, everything exposed to the elements.
Anyone have any experience with a nice 433MHz temperature I can use outdoors without worrying about it going bad? I like this IP66 one, for example, but haven’t tried it yet to see if it works with OMG or RTL_433: Ecowitt WN34L
I got the Ecowitt WN34L and it’s great. I purchased the “Oceania” version so it’s 433MHz. I’m using RTL_433 on a Raspberry Pi to publish to MQTT. Like $20
I also got the Ecowitt WH32_EP, which has an outdoor-rated, highly accurate sensor on it. It’s like $60, and I do the same thing with it. I had to put the transmitter part into a waterproof enclosure with a cable gland to protect it, but otherwise it’s great.
I’m checking out the OpenMQTTGateway project right now, which has an ESP-based RTL_433 implementation. I tried it in the past but it didn’t support the FSK protocol that these Ecowitt sensors use, but there seems to be movement on this front now. So I’ll try that so maybe I can get rid of the Pi + SDR thing and just have a small ESP with a CC1101 doing everything.
The current development version is the best to use with the Ecowitt, Froggit, Ambient Weather etc. weather stations, all rebranded Fineoffset stations, using FSK. The important thing here is to set the frequency to 868.35MHz if the station is a 868 version.
This works best with a compatible LilyGo (v2.1 1.6(.1)) or Heltec board, again depending in the 433 or 868MHz version, without any soldering required. With auto-discovery of OpenMQTTGateway, to get something like
Thanks @DigiH, I got it working with an ESP32 + CC1101 transceiver! No more Pi required. Using OMG + RTL_433_ESP module running on the ESP32, I’ve brought the complexity and cost of receiving my Ecowitt FSK sensors from $50 to $14.
The outdoor Ecowitt WH32_EP has been running for over a year now on the same two AA batteries. The WN34L is at 50% battery after the same period. Needless to say, very happy with my setup.
