Shelly1 PM Mini Gen 3 throwing invalid check sum, junk on wire error

ESPHome
1

I used the config file Here for my 1PM mini Gen3 but I’m getting stuff like:

[15:40:36.893][W][bl0942:082]: BL0942 invalid checksum! 0xB2 != 0xFF
[15:40:37.114][W][bl0942:082]: BL0942 invalid checksum! 0xB0 != 0xFF
[15:40:37.337][W][bl0942:058]: Junk on wire. Throwing away partial message (22 bytes)
[15:40:37.527][W][bl0942:082]: BL0942 invalid checksum! 0xB1 != 0xFF
[15:40:37.751][W][bl0942:082]: BL0942 invalid checksum! 0xB0 != 0xFF

I tried stuff like:

uart:
  id: uart_0
  tx_pin: GPIO6
  rx_pin: GPIO7
  baud_rate: 4800
  stop_bits: 1
  rx_buffer_size: 512

as well but NOGO.

Has anyone else encountered this or have a solution? thank you

2

Is baud rate correct?

3

the esphome devices config I linked had 9600, which is what I used originally. The ESPHome page for the chip Here states

The communication with this component is done via a UART. You must therefore have a uart: entry in your configuration with both the TX and RX pins set to some pins on your board and the baud rate set to 4800 with 1 stop bit.

Which I also tried. I also tried switching the the arduino framework as I know esp-idf can have issues sometimes.

4

So

doesn’t work… With that yaml?

5

It is working, however, I’m getting spammed nonstop the the mentioned checksum error. like several a second

6

Exclude logs from that component.

7

AH! I think I solved it with this.

I’m guessing there is some noise in the circuit which is solved with the pullup?

8

It’s not completely clear to me… Quick look at the bl0942 datasheet gives that in uart-mode rx/tx lines need external pull-up. Maybe Shelly didn’t use them or they are too weak.