HLK-LD2410 24 GHz radar: specs and pinout
A 24 GHz FMCW radar module from Hi-Link that senses moving and stationary people, reports a presence output on one pin and gives status and distance data over a serial port. The plain LD2410 has no Bluetooth; Hi-Link lists the LD2410B and LD2410C as the versions with Bluetooth.
Specs
| Spec | Value | Source |
|---|---|---|
| Operating frequency and method | 24 GHz to 24.25 GHz; FMCW; sweep bandwidth 250 MHz | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 2 (page 10) |
| Supply voltage | 5 V (5 V to 12 V accepted) | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 1 and Table 2 (pages 5 and 10) |
| Supply current | 80 mA average; the manual's measurement plot shows about 41 mA to 152 mA | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 2 and Figure 11 (page 10) |
| Interface and logic level | One GPIO output (OUT) and one UART; module I/O level 3.3 V | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 2 (page 10) and section 5.1 |
| Serial port defaults | 256000 baud, 1 stop bit, no parity | source HLK-LD2410 User Manual V1.02 (2022-6-8), section 5.1 (page 5) |
| Detection distance | 0.75 m to 6 m, adjustable (the introduction states the farthest distance as 5 m); distance resolution 0.75 m | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 2 (page 10) and section 1 (page 1) |
| Detection angle | +/-60 degrees | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 2 (page 10) |
| Configurable settings | Farthest motion gate and static gate, sensitivity (0 to 100) for each 0.75 m distance gate, unoccupied delay in seconds; settings stay after power-off | source HLK-LD2410 User Manual V1.02 (2022-6-8), section 5.2 (pages 5-6) |
| Ambient temperature | -40 to 85 C | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 2 (page 10) |
| Size and pads | 7 mm x 35 mm; five 0.6 mm holes at 1.27 mm pitch (headers are not fitted by default per the manual) | source HLK-LD2410 User Manual V1.02 (2022-6-8), section 4.1 (page 4) |
Power
| Value | Source | |
|---|---|---|
| Supply | 5 V (5 V to 12 V accepted) | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 2 and Figure 11 (page 10) |
| Current | 80 mA average (about 41 mA to 152 mA in the manual's measurement) | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 2 and Figure 11 (page 10) |
Pinout
Pin names and numbers 1 to 5 are from Hi-Link's table for the LD2410; the manual's photo shows the pads in a different physical order from the table, so match the labels printed on the board. Hi-Link's page says the five pin holes are reserved and headers are not fitted by default.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| OUT | Target status output | 3.3 V I/O level | High level when a person is detected, low level when none is | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 1 (page 5) |
| UART_Tx | Serial port Tx | 3.3 V I/O level | Module transmit pin | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 1 (page 5) |
| UART_Rx | Serial port Rx | 3.3 V I/O level | Module receive pin | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 1 (page 5) |
| GND | Power ground | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 1 (page 5) | ||
| VCC | Power input | 5 V (5 V to 12 V accepted) | source HLK-LD2410 User Manual V1.02 (2022-6-8), Table 1 (page 5) |
Build with it
Project ideas for the HLK-LD2410 24 GHz radar. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- Room occupancy display: The ESP32 is a 3.3 V board, matching the radar's 3.3 V I/O. Power the radar's VCC from the ESP32 board's 5 V pin (80 mA average, peaks to about 152 mA). Use it in your own space and tell anyone who shares it that a radar sensor is installed.
- Desk time tracker: The radar OUT line goes high when someone is present, and the DS3231 stamps each session. This is for you at your own desk; do not use it to monitor other people without their consent.
- Radar distance-gate viewer: The Pico's UART is 3.3 V like the radar, at the default 256000 baud. Show the status on the OLED to tune the 0.75 m gates and sensitivity. Keep the radar away from fans and curtains. A learning project, not a safety device.
Common mistakes
- Looking for Bluetooth or the phone app: Hi-Link's manual for the plain LD2410 describes only the GPIO output and the UART, and its download folder lists the LD2410B and LD2410C separately as the versions with Bluetooth, so configure this one over the serial port with the PC tool (source: HLK-LD2410 User Manual V1.02 (2022-6-8) and link)
- Connecting the output straight to a 5 V pin or feeding the serial lines from 5 V: the module's I/O level is 3.3 V while the supply is 5 V to 12 V, so use a 3.3 V board or level shifting on the signal pins (source: HLK-LD2410 User Manual V1.02 (2022-6-8), section 5.1 and Table 2)
- Putting it behind metal or in front of moving objects: the manual says an enclosure must pass 24 GHz and contain no metal, and moving curtains, plants in an air flow, fans and animals disturb detection (source: HLK-LD2410 User Manual V1.02 (2022-6-8), section 5.5 page 9)
Not covered by the official source
- The manual gives the farthest detection distance as 5 m in the introduction and 6 m in the specification table.
- The serial command and data-frame details are in Hi-Link's separate serial protocol document, which is not used for the values on this page.
- The manual does not state the module's logic-input tolerance above 3.3 V.