SEN0610 ( c4001 12m) Not Detected with Ardunio

Here is the Python Code to use with the Raspberry Pi.   

Use this Python script to interpret the data coming off the serial GPIO pins 14 and 15.

#!/usr/bin/env python3
import serial
import time

# Open UART
ser = serial.Serial('/dev/serial0', 115200, timeout=0.5)

def parse_frame(frame):
  # Byte 0: header (0x55)
  # Byte 2: presence flag (1 = presence, 0 = none)
  if len(frame) < 3:
      return None
  return frame[2] != 0

buffer = bytearray()

print("C4001 Presence Detection Started...")

try:
  while True:
      if ser.in_waiting:
          data = ser.read(ser.in_waiting)
          buffer.extend(data)
          
          # Process in 5-byte frames (adjust if your module sends more)
          while len(buffer) >= 5:
              frame = buffer[:5]
              buffer = buffer[5:]
              detected = parse_frame(frame)
              if detected is not None:
                  if detected:
                      print("Presence Detected")
                  else:
                      print("No Presence")
      time.sleep(0.1)

except KeyboardInterrupt:
  print("\nExiting...")
  ser.close()

---------------------------------

You can also use this simple script to dump raw hex…

#!/usr/bin/env python3

import serial

ser = serial.Serial('/dev/serial0', 115200, timeout=0.5)

while True:
  if ser.in_waiting:
      data = ser.read(ser.in_waiting)
      print(data.hex(), end=' ')

The wiring diagram on the DFRobot website is misleading as you must be connected to 3.3V logic .  I've been able to get something working with a Raspberry Pi 3 B+.  

On Raspberry Pi (40-pin header):

C4001 Pin   Pi Pin                 Notes

VCC          3.3V (pin 1)         Must be 3.3V, not 5V

GND          GND  (pin 6)         Any GND pin

TX       GPIO15 (Pin 10)          Sensor → Pi (RX)

RX       GPIO14 (Pin 8)           Pi → Sensor (TX)

NOTE: 

If /dev/serial0 is missing → go to:

sudo raspi-config 

     → Interface Options 

         → Serial Port

               Disable login shell over serial

               Enable serial hardware

Reboot

Run the standard I2C scanner example:

#include <Wire.h>
void setup() {
 Wire.begin();
 Serial.begin(115200);
 while (!Serial);
 Serial.println("\nI2C Scanner");
}
void loop() {
 byte error, address;
 int nDevices = 0;

 for(address = 1; address < 127; address++ ) {
   Wire.beginTransmission(address);
   error = Wire.endTransmission();

   if (error == 0) {
     Serial.print("I2C device found at address: 0x");
     Serial.println(address, HEX);
     nDevices++;
   }
 }

 if (nDevices == 0)
   Serial.println("No I2C devices found\n");
 else
   Serial.println("Done\n");

 delay(3000);
}
 

If this scanner doesn’t find 0x62. I²C mode is not actually enabled, or the sensor is damaged.