HLK-LD2420
Also known as: LD2420 · Hi-Link LD2420 · Presence & motion
The cheapest way into mmWave — about the price of two PIRs — and 3.3 V-friendly so it wires straight to an ESP32 with no level shifting.
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At a glance
⚑ flag an error| Measures | presence, motion |
|---|---|
| Accuracy | 24 GHz budget presence radar |
| Interface | UART |
| Supply | 3.3 V |
| Battery-viable | No (continuous draw) |
| ESPHome | Native ESPHome component — ld2420 |
| Typical price | $2-3 (street, varies) |
Compare all sensor modules in one table →
Which one do I buy?
Spend the extra $2 on an LD2410C unless you're buying ten.
Clone check
HIGH clone risk. Notorious firmware chaos: different batches speak different report formats and some need specific ESPHome versions. Budget for fiddling.
Good for
Gotchas to know
- Firmware-version chaos across batches is the defining complaint — two 'identical' modules may need different configs.
- Less tunable and shorter-range than the LD2410; treat it as a smart PIR replacement.
Wiring it up
Give it a hardware UART (UART1/2 on any ESP32) rather than software serial — the radars talk at 256000 baud. Any dev board works; the DevKitC class is the default host, and if you're building a sensor-plus-screen device, pick a display board with spare pins like the JC3248W535.