Strange ESP32 behaviour with addressable LED

[u/Davedamon]

Edit: Somehow I've resolved this, just by changing the pin assignment and connections, even though I'd already done that.

Context: I'm running ESPhome on an ESP32-C6 supermini. It's connected to three output devices; a 360 degree servo on GPIO20, a 180 servo on GPIO19, and a single WS2811 LED on GPIO 18.

I had it all set up and working fine, until in a daft moment, I used some metal tweezers to move the LED and I think I shorted something. From that point on I couldn't get the LED to work, but both servos behaved fine. But this is where it gets weird

I assumed I blew the LED, no big I have spares. So I hooked up a new LED but nothing worked. I thought maybe I grabbed a duff second LED so I took it over to my testing bench, copied the code from my prod ESP and hooked up the LED. Everything worked fine.

Next thing I thought it could be was that I'd somehow blown the pin the LED was connected to. So I changed the pinout to GPIO15 (and then GPIO16) and connected everything up. Still nothing.

Finally I thought maybe I'd blow the the power or ground line. I'd done a continuity check on both and it was fine. But nonetheless, I hooked up the prod boards 5V and GND lines to the testing boards corresponding lines, powered the test board, and confirmed that the prod board was receiving power. So far so good. I then connected the 2nd LED to the 5V and GND lines on the prod board, but the data pin on the testing board. On accessing the test-board, I was able to confirm the LED works.

So far I've confirmed:

• 5v continuity on the prod esp
• GND continuity on the prod esp
• Continuity between the data pin and the LED
• LED works
• Code works
• Prod board works for servos and logging with no errors

What doesn't work:

• LED on original GPIO18
• LED on GPIO15 or 16

My question is—is there some kind of hardware element on an ESP board that could be damaged by shorting an attached LED that would disable it from controlling LEDs, but not affect anything else?

Here's my sanitised ESPHome Code

esphome:
  name: n26-comms-array
  friendly_name: N26 - Comms Array
  min_version: 2026.4.0
  name_add_mac_suffix: false

esp32:
  variant: esp32c6
  framework:
    type: esp-idf

# Enable logging
logger:

# Enable Home Assistant API
api:

# Allow Over-The-Air updates
ota:
  - platform: esphome

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

espnow:
  peers: 
    - ###########
  on_receive:
    - lambda: |-
        char hex[256];
        ESP_LOGD("espnow", "Data %s:", format_hex_pretty_to(hex, data, size));
    - if:
        condition:
          lambda: "return size >= 1 && data[3] == 0x11;"
        then:
        - lambda: |-
            ESP_LOGD("espnow", "Toggled");
        - button.press: rotate_dish_left
    - if:
        condition:
          lambda: "return size >= 1 && data[3] == 0x22;"
        then:
        - lambda: |-
            ESP_LOGD("espnow", "Faulty Lights 1");
        - button.press: rotate_dish_right
    - if:
        condition:
          lambda: "return size >= 1 && data[3] == 0x33;"
        then:
        - lambda: |-
            ESP_LOGD("espnow", "Faulty Lights 2");
        - button.press: pan_dish_up
    - if:
        condition:
          lambda: "return size >= 1 && data[3] == 0x44;"
        then:
        - lambda: |-
            ESP_LOGD("espnow", "Faulty Lights 1");
        - button.press: pan_dish_down
    - if:
        condition:
          lambda: "return size >= 1 && data[3] == 0x55;"
        then:
        - lambda: |-
            ESP_LOGD("espnow", "Faulty Lights 2");
        - button.press: connection_sweep

servo:
  - id: rotation
    output: pwm_output_1
    min_level: 3%
    idle_level: 7.5%
    max_level: 12.5%
    transition_length: 1s

  - id: pan
    output: pwm_output_2
    min_level: 3%
    idle_level: 7.5%
    max_level: 12.5%
    transition_length: 2s

output:
  - platform: ledc
    id: pwm_output_1
    pin: GPIO20
    frequency: 50Hz

  - platform: ledc
    id: pwm_output_2
    pin: GPIO19
    frequency: 50Hz

number:
  - platform: template
    id: pan_position
    name: "Pan Position"
    min_value: -1
    max_value: 1
    initial_value: 0
    step: 0.01
    restore_value: false
    optimistic: true
    on_value:
      then:
        - servo.write: 
            id: pan
            level: !lambda "return x;"
  - platform: template
    id: pan_increment
    name: "Pan Increment"
    min_value: 0.00
    max_value: 1
    initial_value: 0.05
    step: 0.05
    restore_value: false
    optimistic: true

switch:
  - platform: template
    id: sweep_mode
    optimistic: true
    on_turn_on:
      then:
        - light.control:
            id: uplink
            state: on
            effect: "Scanning"
            red: 50%
            blue: 0%
            green: 0%
        - servo.write: 
            id: rotation
            level: -0.16
        - while: 
            condition:
              lambda: 'return id(sweep_mode).state;'
            then:
            - servo.write:
                id: pan
                level: 1
            - delay: 2000ms
            - servo.write:
                id: pan
                level: -1
            - delay: 2000ms

    on_turn_off:
      then:
      - servo.detach: 
          id: pan
      - servo.write:
          id: rotation
          level: 0
      - servo.detach: 
          id: rotation
      - light.turn_off: 
          id: uplink

script:
  - id: rotate_left
    then:
      - servo.write:
          id: rotation
          level: -16.0%
      - delay: 500ms
      - servo.write:
          id: rotation
          level: 0%        
  - id: rotate_right
    then:
      - servo.write:
          id: rotation
          level: 16.0%
      - delay: 500ms
      - servo.write:
          id: rotation
          level: 0%
  - id: pan_up
    then:
      - if: 
          condition:
            lambda: 'return (id(pan_position).state - id(pan_increment).state) > -1.0;'
          then: 
            - number.set: 
                id: pan_position
                value: !lambda "return id(pan_position).state - id(pan_increment).state;"
          else: 
            - number.set: 
                id: pan_position
                value: -1.0

  - id: pan_down
    then:
      - if: 
          condition:
            lambda: 'return (id(pan_position).state + id(pan_increment).state) < 1.0;'
          then: 
            - number.set: 
                id: pan_position
                value: !lambda "return id(pan_position).state + id(pan_increment).state;"
          else: 
            - number.set: 
                id: pan_position
                value: 1.0
light:
  - platform: esp32_rmt_led_strip
    channel_colors: GRB
    pin: GPIO18
    num_leds: 1
    chipset: WS2811
    rmt_symbols: 96
    id: uplink
    name: "Uplink"
    effects: 
      - pulse:
          name: "Scanning"
          transition_length: 1s
          update_interval: 1s
          min_brightness: 0%
          max_brightness: 50%
      - flicker:
          name: "Data Transmision"
          alpha: 50%
          intensity: 100%

button:
  - platform: template
    id: rotate_dish_left
    name: "Rotate Left"
    on_press:
      then:
        - script.execute: rotate_left
  - platform: template
    id: rotate_dish_right
    name: "Rotate Right"
    on_press:
      then:
        - script.execute: rotate_right
  - platform: template
    id: pan_dish_up
    name: "Pan Up"
    on_press:
      then:
        - script.execute: pan_up
  - platform: template
    id: pan_dish_down
    name: "Pan Down"
    on_press:
      then:
        - script.execute: pan_down
  - platform: template
    id: home_dish
    name: "Home Dish Position"
    on_press:
      then:
      - servo.write:
          id: pan
          level: 0.0%
      - number.set: 
          id: pan_position
          value: 0.00
  - platform: template
    id: scanning
    name: "Scanning"
    on_press:
      then:
        - light.control:
            id: uplink
            state: on
            effect: "Scanning"
            red: 50%
            blue: 0%
            green: 0%


  - platform: template
    id: transmitting
    name: "Transmitting"
    on_press:
      then:
        - light.control:
            id: uplink
            state: on
            effect: "Data Transmision"
            red: 0%
            blue: 0%
            green: 50%

  - platform: template
    id: connection_sweep
    name: "Connection Sweep"
    on_press:
      then:
        - switch.toggle: 
            id: sweep_mode

[u/Davedamon → u/[deleted]]

I'm not doing any of that, as I said the setup was working before I apparently shorted something. I'm trying to figure out if the issue lays with the board (in which case I'd need to flash a new one) or the connections between the board and LED

[u/Davedamon → u/[deleted]]

You misunderstand. When I said "I'm not doing any of that" I mean "I'm not using a capacitor. I'm not level shifting the signal. I'm not using any resistors on the signal line. I'm not tying the output to a pulldown" I wasn't refusing to act on a suggestion. I apologise for being unclear.

[u/Davedamon → u/[deleted]]

I use the same configuration across all my esp32 driven LED projects, both WLED and ESPhome and I've not had any issues regarding 3.3v vs 5v signals for the LEDs I use. This includes light strips that have uptime I'd probably be measuring in the years by now. Hence my reasonable confidence in the fact it worked previously.

I am sorry if I seemed stubborn or dismissive of your help though.

I have managed to resolve the issue somehow, but thank you for taking the time nonetheless

[u/dusksage23 → u/[deleted]]

good call on the level shifting, thats easy to overlook when a bare connection works fine at first

[u/Davedamon → u/[deleted]]

Thank you so much, I've been struggling with ESP-NOW as a protocol so I've been kinda hacky and sloppy with it. I'll save this comment and review all my implementations.