HLK-LD2420 mmWave presence radar with ESP32

Supply 3.3 V Bus GPIO Measures presence, distance
3V3GNDOT1RXOT2

Pins and ESP32 wiring

PinRoleESP32 pinNotes
3V3Power3V3Needs 3.3 V. Pin order may differ by board revision: check the silkscreen
GNDGroundGND
OT1Output (the part drives it)D25UART TX of the radar. Connect to an ESP32 RX pin (115200 or 256000 baud, depends on firmware)
RXInput (the ESP32 drives it)D26UART: the part receives data here. Connect to an ESP32 TX pin
OT2Output (the part drives it)D27HIGH when a person is present (3.3 V)

Suggested wiring for the 30-pin ESP32 DevKit, avoiding flash, input-only and strapping pins. BoardPilot checks it for you as you wire.

Sources

Try it in 3D in BoardPilot

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