Help with UART on ESP32-C6-DevKitC-1

hb9ezs · January 23, 2025, 8:49am

I just tried the 3.3V TX on the WL-134 RFID reader, but this neither worked with the ESP32, nor with the Arduino.

I also tried a voltage divider with a 1kΩ and a 2kΩ resistor in combination with the 5V TX, but this didn’t work either.

I’m really out of ideas…

Karosm · January 23, 2025, 11:14am

Let’s take some odds out. Connect Gpio4 to Gpio5 with jumper wire.

logger:
  baud_rate: 0

uart:
  tx_pin: GPIO4
  rx_pin: GPIO5
  baud_rate: 9600
  debug:
    direction: BOTH
    dummy_receiver: true
    after:
      delimiter: "\n"
    sequence:
      - lambda: UARTDebug::log_string(direction, bytes);

interval:
  - interval: 10s
    then:
      - uart.write: "Hello World\r\n"

If you don’t get anything received, I don’t know what to think next…

hb9ezs · January 23, 2025, 11:32am

Great idea, this works!
This is the first time I see something on the UART RX of the ESP32

Karosm · January 23, 2025, 11:40am

Post some log…

hb9ezs · January 23, 2025, 12:02pm

Forget my last reply, I was wrong. In the logs I only see that the ESP32 posted something to TX.

[12:58:24][D][uart_debug:158]: >>> "Hello World\r\n"
[12:58:34][D][uart_debug:158]: >>> "Hello World\r\n"
[12:58:44][D][uart_debug:158]: >>> "Hello World\r\n"
[12:58:54][D][uart_debug:158]: >>> "Hello World\r\n"
[12:59:04][D][uart_debug:158]: >>> "Hello World\r\n"
[12:59:14][D][uart_debug:158]: >>> "Hello World\r\n"
[12:59:24][D][uart_debug:158]: >>> "Hello World\r\n"
[12:59:34][D][uart_debug:158]: >>> "Hello World\r\n"
[12:59:44][D][uart_debug:158]: >>> "Hello World\r\n"

Karosm · January 23, 2025, 12:56pm

Remove the line
baud_rate: 0
Esphome should configure second UART on your pins.
Post the log when compiling.

hb9ezs · January 23, 2025, 1:16pm

Here are my logs:

Logs

INFO ESPHome 2024.12.2
INFO Reading configuration /config/esphome/catdoor.yaml...
WARNING The selected ESP-IDF framework version is not the recommended one. If there are connectivity or build issues please remove the manual version.
WARNING The selected ESP-IDF framework version is not the recommended one. If there are connectivity or build issues please remove the manual version.
INFO Generating C++ source...
INFO Updating https://github.com/espressif/[email protected]
INFO Compiling app...
Processing catdoor (board: esp32-c6-devkitc-1; framework: espidf; platform: platformio/[email protected])
--------------------------------------------------------------------------------
HARDWARE: ESP32C6 160MHz, 320KB RAM, 8MB Flash
 - framework-espidf @ 3.50301.0 (5.3.1) 
 - tool-cmake @ 3.16.9 
 - tool-ninja @ 1.10.2 
 - tool-riscv32-esp-elf-gdb @ 12.1.0+20221002 
 - tool-xtensa-esp-elf-gdb @ 12.1.0+20221002 
 - toolchain-esp32ulp @ 2.35.0-20220830 
 - toolchain-riscv32-esp @ 13.2.0+20240530
Reading CMake configuration...
Dependency Graph
|-- noise-c @ 0.1.6
Compiling .pioenvs/catdoor/src/main.cpp.o
Linking .pioenvs/catdoor/firmware.elf
RAM:   [=         ]  11.5% (used 37596 bytes from 327680 bytes)
Flash: [===       ]  26.3% (used 1033557 bytes from 3932160 bytes)
Building .pioenvs/catdoor/firmware.bin
Creating esp32c6 image...
Successfully created esp32c6 image.
esp32_create_combined_bin([".pioenvs/catdoor/firmware.bin"], [".pioenvs/catdoor/firmware.elf"])
Wrote 0x10c6c0 bytes to file /data/build/catdoor/.pioenvs/catdoor/firmware.factory.bin, ready to flash to offset 0x0
esp32_copy_ota_bin([".pioenvs/catdoor/firmware.bin"], [".pioenvs/catdoor/firmware.elf"])
========================= [SUCCESS] Took 29.94 seconds =========================
INFO Successfully compiled program.
INFO Connecting to 192.168.1.164 port 3232...
INFO Connected to 192.168.1.164
INFO Uploading /data/build/catdoor/.pioenvs/catdoor/firmware.bin (1033920 bytes)
Uploading: [============================================================] 100% Done...

INFO Upload took 3.23 seconds, waiting for result...
INFO OTA successful
INFO Successfully uploaded program.
INFO Starting log output from 192.168.1.164 using esphome API
INFO Successfully connected to catdoor @ 192.168.1.164 in 4.098s
INFO Successful handshake with catdoor @ 192.168.1.164 in 0.084s
[13:57:46][I][app:100]: ESPHome version 2024.12.2 compiled on Jan 23 2025, 13:57:17
[13:57:46][C][wifi:600]: WiFi:
[13:57:46][C][wifi:428]:   Local MAC: ********
[13:57:46][C][wifi:433]:   SSID: [redacted]
[13:57:46][C][wifi:436]:   IP Address: 192.168.1.164
[13:57:46][C][wifi:439]:   BSSID: [redacted]
[13:57:46][C][wifi:441]:   Hostname: 'catdoor'
[13:57:46][C][wifi:443]:   Signal strength: -58 dB ▂▄▆█
[13:57:46][C][wifi:447]:   Channel: 6
[13:57:46][C][wifi:448]:   Subnet: 255.255.255.0
[13:57:46][C][wifi:449]:   Gateway: 192.168.1.1
[13:57:46][C][wifi:450]:   DNS1: 0.0.0.0
[13:57:46][C][wifi:451]:   DNS2: 0.0.0.0
[13:57:46][C][logger:185]: Logger:
[13:57:46][C][logger:186]:   Level: DEBUG
[13:57:46][C][logger:188]:   Log Baud Rate: 115200
[13:57:46][C][logger:189]:   Hardware UART: UART0
[13:57:46][C][uart.idf:159]: UART Bus 1:
[13:57:46][C][uart.idf:160]:   TX Pin: GPIO4
[13:57:46][C][uart.idf:161]:   RX Pin: GPIO5
[13:57:46][C][uart.idf:163]:   RX Buffer Size: 256
[13:57:46][C][uart.idf:165]:   Baud Rate: 9600 baud
[13:57:46][C][uart.idf:166]:   Data Bits: 8
[13:57:46][C][uart.idf:167]:   Parity: NONE
[13:57:46][C][uart.idf:168]:   Stop bits: 1
[13:57:46][C][captive_portal:089]: Captive Portal:
[13:57:46][C][mdns:116]: mDNS:
[13:57:46][C][mdns:117]:   Hostname: catdoor
[13:57:46][C][esphome.ota:073]: Over-The-Air updates:
[13:57:46][C][esphome.ota:074]:   Address: 192.168.1.164:3232
[13:57:46][C][esphome.ota:075]:   Version: 2
[13:57:46][C][esphome.ota:078]:   Password configured
[13:57:46][C][safe_mode:018]: Safe Mode:
[13:57:46][C][safe_mode:019]:   Boot considered successful after 60 seconds
[13:57:46][C][safe_mode:021]:   Invoke after 10 boot attempts
[13:57:46][C][safe_mode:022]:   Remain in safe mode for 300 seconds
[13:57:46][C][api:140]: API Server:
[13:57:46][C][api:141]:   Address: 192.168.1.164:6053
[13:57:46][C][api:143]:   Using noise encryption: YES
[13:57:47][D][api:103]: Accepted 192.168.1.126
[13:57:47][D][api.connection:1446]: Home Assistant 2025.1.2 (192.168.1.126): Connected successfully
[13:57:51][D][uart_debug:158]: >>> "Hello World\r\n"
[13:58:01][D][uart_debug:158]: >>> "Hello World\r\n"
[13:58:11][D][uart_debug:158]: >>> "Hello World\r\n"
[13:58:21][D][uart_debug:158]: >>> "Hello World\r\n"
[13:58:31][D][uart_debug:158]: >>> "Hello World\r\n"
[13:58:41][D][uart_debug:158]: >>> "Hello World\r\n"

And here is my current config:

Config

esphome:
  name: "catdoor"
  friendly_name: Cat Door

esp32:
  board: esp32-c6-devkitc-1
  flash_size: 8MB
  variant: esp32c6
  framework:
    type: esp-idf
    version: 5.3.1
    platform_version: 6.9.0

uart:
  tx_pin: GPIO4
  rx_pin: GPIO5
  baud_rate: 9600
  debug:
    direction: BOTH
    dummy_receiver: true
    after:
      delimiter: "\n"
    sequence:
      - lambda: UARTDebug::log_string(direction, bytes);

interval:
  - interval: 10s
    then:
      - uart.write: "Hello World\r\n"

logger:

api:
  encryption:
    key: "***"

ota:
  - platform: esphome
    password: "***"

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  manual_ip:
    static_ip: 192.168.1.164
    gateway: 192.168.1.1
    subnet: 255.255.255.0
  power_save_mode: none
  ap:
    ssid: "***"
    password: "***"

captive_portal:

Karosm · January 23, 2025, 1:49pm

Ok, now pins 4/5 are set on UART1 and your code looks generally ok.
But I’m not sure where uart.write is writing, UART0 or UART1.

add id to your uart component:
id: bus1
and replace the interval component with this:

interval:
  - interval: 10s
    then:
      - uart.write:
          id: bus1
          data: "Hello World\r\n"

hb9ezs · January 23, 2025, 2:04pm

I have tried this, but got the same result.

Also, I have removed the version definition in my config due to the warning in the logs, but this also didn’t help.

Karosm · January 23, 2025, 2:14pm

Ok, we have tested on both uarts, different pins etc.
My tool pack is empty.
I think that uart debug simply doesn’t work for C6 on this software version.
Or all your jumper wires are broken…

hb9ezs · January 23, 2025, 3:20pm

In this post, the ESP32-C6-DevKitC-1 worked with UART, so I think it should be possible:

@matteor how do your logs looks like? Can you see the UART RX?

Karosm · January 23, 2025, 4:31pm

It’s slightly different because there is a real device/component.
Yours relies on debug option dummy_receiver.

hb9ezs · January 23, 2025, 8:34pm

Wow, it worked!!
I have disabled the debugger and used the WL-134 text component:

[21:23:40][D][text_sensor:064]: 'Transponder Code': Sending state '900158002020048'
[21:23:41][D][uart_debug:114]: <<< 00:02:30:44:45:37:37:41:39:43:34:32:34:38:33:30:31:31:30:30:30:30:30:30:30:30:30:30:03:FC:03
[21:23:42][D][text_sensor:064]: 'Transponder Code': Sending state '900158002020048'
[21:23:43][D][uart_debug:114]: <<< 02:30:44:45:37:37:41:39:43:34:32:34:38:33:30:31:31:30:30:30:30:30:30:30:30:30:30:03:FC:03

Here is the config I used:

Config

esphome:
  name: cat-sensor
  friendly_name: Cat Sensor

esp32:
  board: esp32-c6-devkitc-1
  framework:
    type: esp-idf

uart:
  - rx_pin: GPIO4
    baud_rate: 9600
    id: myuart1
    debug:

text_sensor:
 - platform: wl_134
   name: Transponder Code

logger:
  level: DEBUG

api:
  encryption:
    key: "*****"

ota:
  - platform: esphome
    password: "*****"

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  manual_ip:
    static_ip: 192.168.1.131
    gateway: 192.168.1.1
    subnet: 255.255.255.0
  power_save_mode: none
  ap:
    ssid: "*****"
    password: "*****"
captive_portal:

I used the 5V TX in combination with the voltage divider 1kΩ/2kΩ.

Looks like the assumption from @Karosm was correct, and the UART debug doesn’t work with this software version and a ESP32-C6. Thank you very much for your help, I really appreciate it!

Karosm · January 23, 2025, 10:08pm

Nice! I kind of expected the problem was on debug, not on uart.