I have just purchased a bunch of SEN0395 sensors for a project. If successful we will run this for all our devices.

However I have some serious issues getting it going as I want.

We are using Esp32 devices and I have followed your guide as good as I can.

https://wiki.dfrobot.com/mmWave_Radar_Human_Presence_Detection_SKU_SEN0395

This is the board pinout we are using:

https://arduino-projekte.info/wp-content/uploads/2020/12/D1_mini_ESP32_pinout.jpg

There are some information I cant seem to find really.

So first of some main questions:

1. RX/TX should these swap to TX/RX on my board?

2. Can I select other GPIO ports for RX/TX like you done in your guide? Or dose it have to be RX/TX (and then see question 1)?

3. In your example you do not use IO2 port. Googling there seems to be most that have used this have connected this port?

My Setup right now for testing:

Sensor RX → TX (GPIO01)

Sensor TX → RX (GPIO03)

Sensor IPO2 → GPIO16

Sensor GND → GND

Sensor V → VCC (5V)

So first test Im using ESPSoftwareSerial library since its not default with ESP32.

Here is the code:

#include <SoftwareSerial.h>
#include "DFRobot_mmWave_Radar.h"

SoftwareSerial mySerial(1, 3);
DFRobot_mmWave_Radar sensor(&mySerial);

void setup()
{
Serial.begin(115200);
mySerial.begin(115200);
pinMode(LED_BUILTIN, OUTPUT);
sensor.factoryReset(); //Restore to the factory settings
sensor.DetRangeCfg(0, 9); //The detection range is as far as 9m
sensor.OutputLatency(0, 0);
}

void loop()
{
int val = sensor.readPresenceDetection();
digitalWrite(LED_BUILTIN, val);
Serial.print("Detection result: ");
Serial.println(val);
delay(1000);
}

Result is this:

12:06:19.394 -> entry 0x400805e4
12:06:19.503 -> ⸮sensorStop
12:06:19.503 -> ⸮sensorStop is not recognized as a CLI command
12:06:19.503 -> Error
12:06:19.503 -> leapMMW:/>factoryReset 0x45670123 0xCDEF89AB 0x956128C6 0xDF54AC89
12:06:21.011 -> factory reset complete
12:06:21.044 -> Done
12:06:21.044 -> leapMMW:/>saveCfg 0x45670123 0⸮CDEF89AB 0⸮956128C6 0xDF54AC89
12:06:21.525 -> no parameter has changed
12:06:21.525 -> Error
12:06:21.525 -> leapMMW:/>sensorStart
12:06:22.616 -> Done
12:06:22.616 -> leapMMW:/>sensorStop
12:06:23.521 -> Done
12:06:23.521 -> leapMMW:/>detRangeCfG -1 0 60
12:06:24.532 -> detRangeCfG is not recognized as a CLI command
12:06:24.532 -> Error
12:06:24.532 -> leapMMW:/>saveCfg 0x45670123 0xCDEF89AB 0xr56128C6 0xDF54AC89
12:06:25.509 -> no parameter has changed
12:06:25.509 -> Error
12:06:25.509 -> leapMMW:/>sensorStart
12:06:26.630 -> Done
12:06:26.630 -> leapMMW:/>sensorStop
12:06:27.527 -> Done
12:06:27.527 -> leapMMW:/>outputLate~cy -1 0 0
12:06:28.519 -> outputLate~cy is not recognized as a CLI command
12:06:28.519 -> Error
12:06:28.519 -> leapMMW:/>saveCfg 0x45670123 0xCDEF89AB 0x956128C6 0x⸮F54AC89
12:06:29.534 -> no parameter has changed
12:06:29.534 -> Error
12:06:29.534 -> leapMMW:/>sensorStart
12:06:30.637 -> Done
12:06:30.637 -> leapMMW:/>
12:06:31.086 -> ..\User_code\main.c line:232
12:06:31.086 -> reset system
12:06:31.187 ->
12:06:31.187 -> leapMMW:/>$JYBSS,0, , , *
12:06:53.307 -> $JYBSS,0, , , *
12:06:54.286 -> $JYBSS,0, , , *
12:06:55.308 -> $JYBSS,0, , , *
12:06:56.284 -> $JYBSS,0, , , *
12:06:57.289 -> $JYBSS,0, , , *
12:06:57.546 -> $JYBSS,1, , , *
12:06:58.549 -> $JYBSS,1, , , *
12:06:59.566 -> $JYBSS,1, , , *
12:07:00.552 -> $JYBSS,1, , , *

So a bunch of errors but then I see the result and it works with 0 and 1. However I do not get any reading on sensor.readPresenceDetection and its even stuck and do not even get a faulty error.

I have tried swaping mySerial(1, 3) to mySerial(3, 1) but then nothing happens. Have also switched the cables so RX→RX and TX→TX but thats not working either.

Then second test I took the code you hade in your example instead where it uses HardwareSerial.

Here is the code:

#include <DFRobot_mmWave_Radar.h>

HardwareSerial mySerial(1);
DFRobot_mmWave_Radar sensor(&mySerial);

void setup()
{
Serial.begin(115200);
mySerial.begin(115200, SERIAL_8N1, 1, 3);//RX,TX
pinMode(LED_BUILTIN, OUTPUT);

sensor.factoryReset(); //Restore to the factory settings
sensor.DetRangeCfg(0, 9); //The detection range is as far as 9m
sensor.OutputLatency(0, 0);
}

void loop()
{
int val = sensor.readPresenceDetection();
digitalWrite(LED_BUILTIN, val);
Serial.print("Detection result: ");
Serial.println(val);

delay(1000);

}

This give me the exact same result as the other code.

So to sumerize. It feels like it has connection with the device since I get this type of result:

12:14:45.596 -> $JYBSS,1, , , *
12:14:46.562 -> $JYBSS,1, , , *
12:14:46.881 -> $JYBSS,0, , , *
12:14:47.880 -> $JYBSS,0, , , *
12:14:47.916 -> $JYBSS,1, , , *

It feels like the commands sent to the unit is not working and it feels like its not sending any results through the sensor. Probably since it looks like it crashed.

Any help on what Im doing wrong here?