The Hi-Link radar decoder: LD2410 vs 2410B/C/S vs 2412 vs 2420 vs 2450
Hi-Link's 24 GHz radar family is the engine of the DIY presence-sensor boom — and a naming scheme so confusing that "LD2410C vs 2410B vs LD2410S vs 2411 vs 2420 vs 2450" is a literal Home Assistant forum thread title. Here's the whole family, decoded.
| Model | What it's for | Range | ESPHome | Price | Verdict |
|---|---|---|---|---|---|
| LD2410 | Zone presence (still + moving) | ~6 m | native (ld2410) | $3–6 | The default. Start here. |
| LD2410B | LD2410 + Bluetooth config app | ~6 m | native (ld2410) | $4–6 | Worth it for the phone-app tuning. |
| LD2410C | LD2410, plain pin header | ~6 m | native (ld2410) | $3–5 | Cheapest of the trio; same radar. |
| LD2410S | Ultra-low-power presence (µA standby) | ~6 m | community configs | $4–6 | The battery-build special; 2–3 months per charge in DIY nodes. |
| LD2412 | Better stationary detection | ~9 m | native (ld2412) | $5–8 | The upgrade for big rooms and very still people. Rising. |
| LD2420 | Budget presence | ~8 m | native (ld2420) | $2–3 | Cheapest mmWave; firmware-batch roulette included. |
| LD2450 | Tracks up to 3 targets with X/Y position | ~6 m | native (ld2450) | $6–10 | Zones and tracking — but weak at motionless bodies. Pair it. |
| LD1125H | Presence/respiration (2022 era) | ~4 m | external only | $10–14 | Superseded by LD2412/2450. Legacy builds only. |
Prices are AliExpress street bands (July 2026). The LD2411S (doppler distance) and LD2402 (older presence part) exist but rarely make sense for new HA builds.
The three-second decision
- Just want reliable room presence? LD2410C. Done.
- Want to tune from your phone? LD2410B (Bluetooth app).
- Big room / people who sit like statues? LD2412.
- Want zones and "who's where"? LD2450 — and read the next section.
- Battery build? LD2410S, the only low-power option.
- Buying ten? LD2420, if you can stomach batch-to-batch firmware chaos.
The dual-radar recipe
The LD2450's superpower (tracking moving targets with coordinates) and its weakness (losing motionless bodies beyond ~2 m) are two sides of the same firmware. That's why 2026's best DIY and commercial sensors — Apollo's R PRO-1 being the flagship example — mount an LD2450 for position plus an LD2412 for stillness and fuse them in ESPHome: the 2450 tells you where, the 2412 guarantees the lights stay on while you nap. Both have native ESPHome components, so the fusion is a few template sensors, not a firmware project.
Family-wide gotchas
- Firmware-batch roulette: not counterfeiting, but batches ship different firmware — the LD2420 is notorious (different report formats), and a late-2025 LD2450 firmware broke its ESPHome component for some units. Buy from the Hi-Link official store and note your firmware version on arrival.
- UART at 256000 baud: the LD2410/2450 talk fast — use hardware UART pins, not software serial.
- Radar sees through thin walls: cap the max-range gates at your room boundary or you'll automate the neighbour's hallway.
- Every one needs tuning: fans, curtains and monitors are motion; the per-gate sensitivity settings exist for exactly this. Budget an evening.
Buy
Conveniently, the Hi-Link official store sells the whole family as options on one listing — LD2410B/C/S, LD2412, LD2450 and siblings:
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Not sure mmWave is even the right tool? The presence-sensor picker compares DIY vs assembled vs retail. All specs: the sensor table.