ESP32 Forum

Solution: see next post!

Since the RMT reception problems I am experiencing always occur when some kind of UART communication is going on - either the Serial output to the PC via USB or display commands via UART2 to a Nextion HMI display - could there be any interference between RMT and UART?
The RMT is working like a charm as soon as I will disconnect both USB and display UART connections. When either of these is plugged in, the RMT gets seemingly less (USB) or no (display UART) data anymore.
Huh...

The problem was the 433MHz receiver module, not the ESP32.

The cheap receiver modules all are amplifying whatever they pick up to a level where they are "seeing" data signals. This is the reason why most 433MHz protocols are sending some lead bytes with a recognizable pattern to let the receivers adjust to the signal level, thus reducing the noise.

In my environment the LCD display added a _lot_ of low-amplitude noise, that got amplified until it prevented the lead-in pattern to be detected.

The solution was to solder a resistor to two pins of the chip on the receiver module, that now is lifting the reaction threshold of the amplifying circuit to a level above the noise. Works like a charm

I found two solutions for two of the most used modules:

• SRX882 with PT4303 chip: https://www.mikrocontroller.net/topic/459520
• RXB6 etc. witch SYN470R chip: http://forum.espruino.com/conversations/268494/

Hi

Do you have any info on how you got the RMT working. I am stuck but cannot find any help.

JT