The Complete Guide to the HLK-LD2450 24GHz Multi-Target Tracking Radar Module

The HLK-LD2450 is a 24GHz FMCW (frequency-modulated continuous-wave) millimeter-wave radar module from Shenzhen Hi-Link, the sibling of the already-published HLK-LD2410. Where the LD2410 answers a yes/no “is someone there” question, the LD2450 tracks up to three separate moving targets simultaneously, each with its own X/Y coordinate and speed, streamed continuously over UART.

LD2410 or LD2450: which do you need?

If you only need occupancy detection, the simpler LD2410 is cheaper and easier to integrate. Reach for the LD2450 when you need to know where someone is in a room, count multiple people, or detect direction of movement.

Specifications and Pinout

Wiring to an ESP32

The module needs a genuine 5V supply (not 3.3V) but its UART logic level is 3.3V-safe for direct connection to an ESP32’s hardware UART. Cross TX/RX between the two devices.

Arduino code (HLK-LD2450 library by RBEGamer)

#include <HardwareSerial.h>
#include <LD2450.h>

HardwareSerial radarSerial(2);
LD2450 radar;

void setup() {
  Serial.begin(115200);
  radarSerial.begin(256000, SERIAL_8N1, 16, 17);
  radar.begin(radarSerial);
}

void loop() {
  radar.read();
  for (int i = 0; i < 3; i++) {
    if (radar.getTargetActive(i)) {
      Serial.printf("Target %d: x=%dmm y=%dmm speed=%dcm/sn",
        i, radar.getTargetX(i), radar.getTargetY(i), radar.getTargetSpeed(i));
    }
  }
  delay(100);
}

The exact method names vary slightly between the several community LD2450 libraries (RBEGamer/HLK-LD2450, darkjumpy/HLK-LD2450_Arduino_Library, Fiooodooor/HLK-LD245X all exist), check the specific library’s own examples, the wiring and 256000-baud UART protocol are the same regardless of which one you pick.

Practical Applications

• Room occupancy counting: track up to 3 people moving through a space.
• Smart lighting zones: turn on only the light near the tracked X/Y position, not the whole room.
• Fall/motion-pattern detection: speed and position data over time can flag unusual movement.
• Privacy-preserving presence: no camera involved, useful where a camera would raise privacy concerns.

Conclusion

The LD2450 gives you real multi-target position tracking that a simple presence sensor like the LD2410 can’t, at the cost of a more involved binary UART protocol. Pair it with an ESP32’s hardware UART for reliable 256000-baud framing.

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