LowPowerLab Forum

Hardware support => RF - Range - Antennas - RFM69 library => Topic started by: Vorms on December 25, 2018, 08:00:44 PM

Title: Noise level
Post by: Vorms on December 25, 2018, 08:00:44 PM
Hello,
I have a noise problem.
I see when the transmitter will send a message, before sending he is hearing about.
If the receive receive someting, the transmitter will no transmit the message until the chanel is free.
That is if I understand well the role of the canSend method
Some times, in my envirronement the waste time can be one second !
For dealing with the noise, I add a method for changing the noise level of the receiver

I am not in a special environnement, I use the RFM69X Library with an ESP32

Am i correct ?

Best regard and marry Chrismass!
Title: Re: Noise level
Post by: Felix on December 26, 2018, 11:58:05 AM
I am not in a special environnement, I use the RFM69X Library with an ESP32
That's likely your problem.
Search around in the forum, you will find some threads where pairing RFM69 with ESP modules causes a noise problem for the RFM69. Those threads also discuss some solutions for this problem.
Title: Re: Noise level
Post by: vc1234 on December 27, 2018, 04:37:10 PM
I had  similar experience with RFM69 connected to ESP8266 and ESP32. In my case, I received garbage at -90/-92 RSSI with a 5 bytes preamble and a two byte sync word meaning that noise was treated as real data. One 8266 was the worst(several incorrect frames per minute),another slightly better, and an ESP32 TTGO had the least noise (about one packet per hour). In comparison a Moteino and a 8MHz Pro Mini received about one /two noise as "correct" frame/packet a day. 

Interestingly, an RPI zero W which I use as a gateway with an RFM69 produced less noise than ESP8266/32.  Not sure how to filter the noise out (if it's even possible at all with boards I use) since I'd prefer to use an 8266 as a gateway to MQTT rather than an RPI.
Title: Re: Noise level
Post by: Felix on December 27, 2018, 07:04:42 PM
Lets see if TomWS will have a say, he's a big fan of ESP boards :)