HMMD mmWave Sensor with NodeMCU ESP8266

ESPHome
1

I tried to use the ESPHome LD2420 24Ghz mmWave Radar configuration with use my HMMD mmWave sensor. I was under the impression that this is the exact same sensor as the HLK-LD2420 motion and presence sensor. Both use the same chip (S3KM1110) according to this site and the board layout, pinout and baud rate are all identical.

I can compile and upload to the NodeMCU and the device shows up in HA with all sensors and buttons. However it is not working as hoped it to be. When looking at the logs in my ESPHome dashboard I see the following errors:

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This suggests that the NodeMCU is not communicating with the sensor, at least that is what I make of it.

Maybe there is something wrong with my configuration or the HMMD sensor is different to the HLK-2420. Any ideas or help to get this working will be greatly appreciated!

This is my YAML config:

esphome:
  name: esp-radar
  friendly_name: esp-radar

esp8266:
  board: nodemcuv2

# Enable logging
logger:
  level: INFO  #You Can Use "INFO" Level
  baud_rate: 0

# Enable Home Assistant API
api:
  encryption:
    key: "some-key-bla-bla-la"

ota:
  - platform: esphome
    password: "some-password-bla-bla-bla"

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

#Example from: https://deploy-preview-2956--esphome.netlify.app/components/sensor/ld2420
uart:
  id: ld2420_uart
  tx_pin: GPIO1  #ESP8266 UART_0
  rx_pin: GPIO3  #ESP8266 UART_0
  baud_rate: 115200
  parity: NONE
  stop_bits: 1
  
# The LD2420 has 16 time gate intervals (0-15) with a gate
# resolution of 0.70 meters
ld2420:

text_sensor:
  - platform: ld2420
    fw_version:
      name: LD2420 Firmware

sensor:
  - platform: ld2420
    moving_distance:
      name : Moving Distance

binary_sensor:
  - platform: ld2420
    has_target:
      name: Presence

select:
  - platform: ld2420
    operating_mode:
      name: Operating Mode

number:
  - platform: ld2420
    presence_timeout:
      name: Detection Presence Timeout
    min_gate_distance:
      name: Detection Gate Minimum
    max_gate_distance:
      name: Detection Gate Maximum
    gate_select:
      name: Select Gate to Set
    still_threshold:
      name: Set Still Threshold Value
    move_threshold:
      name: Set Move Threshold Value
    gate_move_sensitivity:
      name: Move Calibration Sensitivity Factor
    gate_still_sensitivity:
      name: Still Calibration Sensitivity Factor

button:
  - platform: ld2420
    apply_config:
      name: Apply Config
    factory_reset:
      name: Factory Reset
    restart_module:
      name: Restart Module
    revert_config:
      name: Undo Edits

These are the logs after the upload with DEBUG instead of INFO:

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image637×543 62.6 KB

2

I found the solution. I had swapped the rx and tx connections.

This also means that I can confirm that the HMMD mmWave sensor is the exact same sensor as the HLK-LD2420 motion and presence sensor.

1 Like
3

I am in the same situation. Temporary solution was the connection TX<>TX and RX<>RX which is against the logic of UART communication. However, it worked for a couple of minutes and became unavailable. So I switched the wires to RX<>TX TX<>RX and it popped up for another couple of minutes. After that, I was never able to compile it again without the message you have in your log: Component ld2420 is marked as FAILED.

Is your sensor working without troubles?

4

I narrowed down the problem. UART works well without interruption on GPIO1 (TX) 2 (RX), instead of on the TX RX onboard pins (43, 44) for the presence sensor. ESP32-S3 Wroom.