LD2410C mmWave radar
Lessons learned, and how to use it to detect static presence reliably using different still_energy values
to signal on/true and off/false.
I have figured out a good way to get more reliable presence detection with the HLK LD2410 module.
This page will document my approach. Currently this page is a (very) early work (nearly empty) in progress.
Overview
| Manufacturer | HiLink |
|---|---|
| Name | LD2410C |
Datasheet (LD2410C) | HLK-LD2410C_manual_v1.00.pdf |
Serial protocol (LD2410C) | HLK-LD2410C_Serial_communication_protocol_v1.00.pdf |
| Interface | UART |
| Supply voltage |
The LD2410 sensors use a serial protocol over UART. The C variant also has
BLE, which can be disabled in configuration or at runtime.
Variants
There are several variants of the LD2410 sensor:
HLK-LD2410C: UART and BLEHLK-LD2410B: UART and BLEHLK-LD2410B-P: UART only (no BLE)
HLK-LD2410S/HLK-LD2410: UART only (no BLE)
The differences are mainly in form-factor, and only the C variant and some of
the B variants have oboard BLE.
| Name | Datasheet | Serial protocol |
|---|---|---|
HLK-LD2410B | HLK-LD2410B_....pdf | HLK-LD2410B_Serial_co....pdf |
HLK-LD2410 | HLK-LD2410_....pdf | HLK-LD2410_Serial_Cm....pdf |
Note that this page assumes the C variant LD2410C (because that is the
variant that I have).
Pinout
| Pin | Description |
|---|---|
TX | UART TX |
RX | UART RX |
OUT | Pulls HIGH when prescence is detected |
GND | Ground |
VSS | Supply voltage, |
The OUT pin will pull HIGH when presence is detected and the light sensor
is above it's threshold. The light sensor can be disabled, and then the OUT
pin should pull HIGH regardless of the light levels, but this is a bit
unreliable. Since we don't rely on the sensors own internal presence detction
alone, we can ignore this pin anyway.
References
24 GHz Radar Sensor Modules - Shenzhen Hi-Link Electronic Co., Ltd.: All radar modules manufactured and sold by Hi-Link.
HLK-LD2410C 24GHz - Shenzhen Hi-Link Electronic Co., Ltd.: UART and BLE