Connection error for TX/RX pins

Hi,
After a random period of time, the module RAK3172
UART communication error occurs - the microcontroller (ESP32) is not getting any acknowledgement .
By further observing , it is noticed that the power consumption of the gateway RAK gets “stuck” at 6 mA, and is not able to exit this state.

No response to AT commands and 6mA consumption points usually to a crash of the RAK3172.
Are you using a custom firmware on the RAK3172 or AT command interface?

1 Like

Hi,
Thanks for the reply.
We are using AT command interface, when we restart the system communication is restored for a while, but then the problem reappears.

What AT commands are you sending?
Are you using LoRaWAN or LoRa P2P?
Do you have a possibility to listen to the communication between the ESP32 and the RAK3172?
How is the power supply of the RAK3172 done?
Are you using a GPIO of the ESP32 to control RESET of the RAK3172?
Are you controlling the power of the RAK3172 from the ESP32?

    • What AT commands are you sending?-
      AT+PRECV=0, AT+PRECV=65533
      AT+NWM=0\r\n" //first time always respond with AT+NWM not found
      delay 20 ms
      “AT+NWM=0\r\n” //second time repand with OK
      delay 20 ms
      “AT+P2P=868000000:7:125:0:8:14\r\n”
      delay 20 ms
      //enable reception
      “AT+PRECV=0\r\n”
      delay 50 ms
      “AT+PRECV=65534\r\n”
      delay 50 ms
  1. Are you using LoRaWAN or LoRa P2P?
    LoRa P2p

  2. Do you have a possibility to listen to the communication between the ESP32 and the RAK3172? -
    Yes, we are getting acknowledgement from LoRA module to ESP-32
    4.How is the power supply of the RAK3172 done?
    power supply to LoRa module is given with help of a 3.3V switching regulator .
    5.Are you using a GPIO of the ESP32 to control RESET of the RAK3172?
    No, the RESET pin is kept high .
    6.Are you controlling the power of the RAK3172 from the ESP32?
    NO

Maybe it is just in the logs like this but

You cannot combine AT commands like this: AT+PRECV=0, AT+PRECV=65533

Each AT command has to be end with \r\n

You have to wait for the response (OK, AT+ERROR, …) before you send the next command.

AT+P2P=868000000:7:125:0:8:14\r\n

is old version of AT+P2P command. The bandwidth should be set as a single number (0=125, 1=250, 2=500, 3=7.8, 4=10.4, 5=15.63, 6=20.83, 7=31.25, 8=41.67, 9=62.5)

AT commands should not be surrounded by '" “There should not be a single”` at the end of a command.

Are you waiting for the response from the RAK3172 after you send the AT command? A simple delay might not work allways.
Every AT command has a response, with the exception of AT+SLEEP.

To which of the two UARTS of the RAK3172 are you connecting?

Hi,
To which of the two UARTS of the RAK3172 are you connecting?-
UART2_RX, UART2_TX

What is the firmware version on the RAK3172?
Can you check with AT+VER=?

What is the firmware version on the RAK3172?
Can you check with AT+VER=?
RUI_3.5

RUI3 V3.5 has a problem, it was fixed in the newer versions.
Please update to the latest RUI3 version and try again.

Upgrading RAk3172

Hi,
We updated with the latest version, but the mentioned problem still continues.
Do you have any solutions for this?

I have no solution, because I don’t know what is causing it.

I setup an ESP32 Wroover (RAK11200) and connected a RAK3172 over UART to it.
I was running this P2P example code with the beta version of the RAK-Arduino-Library over the several hours and it worked just fine.

++1500 packets, RAK3172 + ESP32 sending every ~30 seconds. Still working.

ESP32 log output:
image

Whether this issue arises due to the selection of antenna ?
we are using Antena ANT-868-ID-1000-SMA and connector W9011M.

I don’t think so unless you power supply is not able to supply the ~100mA current peak required during TX.

The 6mA current you mentioned earlier is normal if the RAK3172 is in RX mode with AT+PRECV=65534.