Documentation

#include <SoftwareSerial.h>

// HLK-2410C TX -> D2, RX -> D3
SoftwareSerial radar(2, 3);

// Frame header / footer bytes from the LD2410 protocol
const uint8_t HEADER[4] = {0xF4, 0xF3, 0xF2, 0xF1};
const uint8_t FOOTER[4] = {0xF8, 0xF7, 0xF6, 0xF5};

uint8_t buf[64];
uint8_t idx = 0;

void setup() {
  Serial.begin(115200);
  radar.begin(256000);  // Default baud
  Serial.println("HLK-2410C ready");
}

void loop() {
  while (radar.available()) {
    uint8_t b = radar.read();
    if (idx < sizeof(buf)) buf[idx++] = b;

    // Look for footer
    if (idx >= 4 &&
        buf[idx-4] == FOOTER[0] && buf[idx-3] == FOOTER[1] &&
        buf[idx-2] == FOOTER[2] && buf[idx-1] == FOOTER[3]) {

      // Target state at byte 8: 0=none, 1=moving, 2=static, 3=both
      uint8_t state = buf[8];
      uint16_t moveDist  = buf[9]  | (buf[10] << 8);
      uint16_t staticDist = buf[12] | (buf[13] << 8);

      Serial.print("State: "); Serial.print(state);
      Serial.print("  Moving: "); Serial.print(moveDist);
      Serial.print("cm  Static: "); Serial.print(staticDist);
      Serial.println("cm");

      idx = 0;
    }
  }
}

#include <HardwareSerial.h>

HardwareSerial radar(2);  // UART2

#define RXD2 16
#define TXD2 17

void setup() {
  Serial.begin(115200);
  radar.begin(256000, SERIAL_8N1, RXD2, TXD2);
  Serial.println("HLK-2410C on ESP32 UART2");
}

void loop() {
  static uint8_t buf[64];
  static uint8_t idx = 0;

  while (radar.available()) {
    uint8_t b = radar.read();
    if (idx < sizeof(buf)) buf[idx++] = b;

    if (idx >= 4 &&
        buf[idx-4] == 0xF8 && buf[idx-3] == 0xF7 &&
        buf[idx-2] == 0xF6 && buf[idx-1] == 0xF5) {

      uint8_t state = buf[8];
      uint16_t moveDist  = buf[9]  | (buf[10] << 8);
      uint16_t staticDist = buf[12] | (buf[13] << 8);
      uint16_t detectDist = buf[15] | (buf[16] << 8);

      Serial.printf("State=%u  Move=%ucm  Static=%ucm  Detect=%ucm\n",
                    state, moveDist, staticDist, detectDist);
      idx = 0;
    }
  }
}

import serial
import time

ser = serial.Serial('/dev/serial0', 256000, timeout=0.1)
FOOTER = bytes([0xF8, 0xF7, 0xF6, 0xF5])

buf = bytearray()

print("HLK-2410C reader started. Ctrl-C to exit.")
try:
    while True:
        data = ser.read(64)
        if data:
            buf.extend(data)
            # Find a complete frame
            while FOOTER in buf:
                end = buf.index(FOOTER) + 4
                frame = bytes(buf[:end])
                del buf[:end]

                if len(frame) >= 17:
                    state = frame[8]
                    move = frame[9] | (frame[10] << 8)
                    static = frame[12] | (frame[13] << 8)
                    names = {0: "None", 1: "Moving", 2: "Static", 3: "Both"}
                    print(f"{names.get(state,'?'):6s}  move={move}cm  static={static}cm")
        time.sleep(0.05)
except KeyboardInterrupt:
    ser.close()

from machine import UART, Pin
import time

uart = UART(0, baudrate=256000, tx=Pin(0), rx=Pin(1))
FOOTER = bytes([0xF8, 0xF7, 0xF6, 0xF5])

buf = bytearray()
print("HLK-2410C on Pico UART0")

while True:
    if uart.any():
        buf.extend(uart.read())
        while FOOTER in buf:
            end = buf.index(FOOTER) + 4
            frame = bytes(buf[:end])
            del buf[:end]
            if len(frame) >= 17:
                state = frame[8]
                move = frame[9] | (frame[10] << 8)
                static = frame[12] | (frame[13] << 8)
                print("state=%d move=%dcm static=%dcm" % (state, move, static))
    time.sleep_ms(50)