mmWave Presence Detection - ESPHome style

Hi everyone! :wave:

I’m trying to get a MR24HPC1 mmWave sensor working with an ESP32C3 Supermini (Tenstar Robot) through ESPHome, but I’m running into a small hurdle. While the device connects successfully, all the sensor states remain “Unknown” in Home Assistant.

Setup Details

Hardware:

  • ESP32C3 Supermini (Tenstar Robot)
  • MR24HPC1 mmWave Sensor

Connections:

ESP32C3 Pin MR24HPC1 Pin
5V VCC
GND GND
GPIO4 (D2) RX
GPIO5 (D3) TX

Software:

  • ESPHome 2024.12.2
  • Latest Home Assistant Core

What’s Working

  • Device successfully connects to WiFi (great signal: -41 dB)
  • Shows up in Home Assistant
  • ESPHome compilation and installation are successful
  • No visible errors in logs

What’s Not Working

  • All sensor entities show as “Unknown”
  • No sensor data seems to be coming through

ESPHome Configuration

Here’s the relevant parts of my YAML:

uart:
  id: uart_bus
  baud_rate: 115200
  rx_pin: 4
  tx_pin: 5
  parity: NONE
  stop_bits: 1

seeed_mr24hpc1:
  id: my_seeed_mr24hpc1

# [Sensor configurations follow...]

What I’ve Tried

  • Direct .bin firmware flash
  • Using ESPHome Builder within Home Assistant
  • Double-checked all wiring connections
  • Verified power supply
  • Enabled DEBUG logging

Logs

The device connects fine, but there’s no sensor data coming through. Here’s a snippet from the logs showing successful connection:

[22:13:33][C][wifi:436]:   IP Address: 192.168.178.86
[22:13:33][C][wifi:443]:   Signal strength: -41 dB ▂▄▆█

Has anyone successfully integrated this sensor with an ESP32C3? Any ideas what I might be missing?
I feel like the issue lies in the connection between the mmwave and the ESP. The Pin layout on the official Xiao ESP32-C3 is different, but i chose the right GPIO Pins for my controller.

Thanks in advance for any help! :pray:

I tried to use the esp32 c3 Supermicro specific UART pins (20 and 21) and changed the code and wiring accordingly. The issue persists.

I think you should first determine if the radar is working properly. For example use a UART to USB device and connect it directly to your computer to see if the radar is actively reporting data.