Seeed Studio 60GHz mmWave Sensor - Human Resting Breathing and Heartbeat Module Review

Introduction

I recently bought a tiny 60GHz radar module to use in a project. This is a really neat little board that claims to be able to read breathing and heart rate data from a subject with 90% accuracy.

It’s made by the Chinese firm Seeed Studio but it was in stock at DigiKey and shipped really quickly. It’ll be shipping back just as quickly.

First attempts

I was pretty inspired by the documentation on the manufacturers’ website - the translation leaves a bit to be desired, but it seems like all the right information is there.

I hooked it up to an Arduino, established a serial connection at 9600 bps, and got absolutely nothing. It sounded like it was working, I could almost hear high-pitched chirps coming from the board, but it didn’t produce any output.

I attached my Saleae Logic Analyzer and took a quick look - it was transmitting but at 115kbps and not 9600. A quick fix and I could start to see some kind of useful data coming in.

I did discover the manufacturer has a github library that can sort of decode the messages.

I made some simple modifications to make this work with the ESP32 (using Serial2 instead of Serial1). Here’s the updated header in case someone has a similar question, but I’m not going to contribute back the rest of my changes because the board is practically unusable.

#include "Arduino.h"
#include "60ghzbreathheart.h"

#include <HardwareSerial.h>
#define RXD2 16
#define TXD2 17

void BreathHeart_60GHz::SerialInit(){

  Serial2.begin(115200, SERIAL_8N1, RXD2, TXD2);
}

// Receive data and process
void BreathHeart_60GHz::recvRadarBytes(){
  static boolean recvInProgress = false;
  static byte ndx = 0;
  byte startMarker = MESSAGE_HEAD;            //Header frame
  byte endMarker = MESSAGE_TAIL;
  byte rb; // Each frame received
  while (Serial2.available() > 0 && newData == false)
  {
    rb = Serial2.read();

    /// rest of the file remains the same

Here’s the output (while pointed at my office wall and far away from me)

What about Windows?

The manufacturer provides a pretty impressive demo using their Windows software. I wondered if it perhaps did some kind of firmware upgrade or calibration procedure that the Arduino software doesn’t.

I ordered a USB<->Serial converter hoping that I could see it work properly and then maybe go back to the logic analyzer to decode the differences in protocol.

Here’s a video showing how well that went:

Conclusion

This is pretty much useless for any of the purposes shown. It might suffice for detecting motion in limited circumstances, but I couldn’t get even slightly close to reproducing what the manufacturer shows it’s capable of.