I bought the mmWave Human Detection Sensor Kit a while ago and it’s been running for over a year and working perfectly with home assistant. The other day I had to unplug it to move a plug around and now the mmwave sensor doesn’t work anymore. The esp32 is working fine and detected in home assitant and the grove temperature and humidity sensor that is plugged in is still working fine, just the mmwave sensor stopped working.
I’ve tried re-installing from ESPHome but still only the temp humidity is working. Does anyone have any ideas what else I could try to troubleshoot this? I haven’t tried reflashing the firmware yet but I’ll try that and see. Could unplugging the device kill the mmwave sensor?
No I haven’t been able to get it working since it stopped. It still works as a temperature humidity sensor in Home Assistant but the mmwave radar hasn’t worked again. I’ve taken the device completely apart and checked all connections and re-flashed the firmware. It seems like the sensor just died. I’ll eventually take it apart again and check for dead capacitors with a multimeter but I replaced it so that isn’t a high priority.
Unplugging the device should not kill it. However, power spikes can damage mmWave modules. Your ESP32 and temp sensor still work fine. That suggests the radar module likely failed. First, check if the radar board LED turns on. Next, measure voltage at the module pins. Then test UART output with a USB-TTL adapter. Also try different ESP32 GPIO pins. Some modules reset their baud rate after power loss. If there is no serial output, it is probably dead. You can build a replacement using this project: https://www.pcbway.com/project/shareproject/ESP32_DevKitC_MMWave_Sensor_LD2420_6e5e9b6d.html. The LD2420 works well with ESPHome and Home Assistant.