A field checklist to get a module outputting good data on the first try. It covers the R60AFD1-V (60 GHz fall), R24AVD1 (24 GHz presence), and the SIP-S serial family. Every item is taken from the module datasheets / user manuals — nothing assumed. Pair it with the minimal UART parser to go from “wires connected” to “data decoded”.
1. Power — do this before anything else
- Supply 4.5–5.5 V (typ 5.0 V) for the 60 GHz modules; ripple must be ≤ 100 mV (R60AFD1-V datasheet §5.2, §9.4).
- Budget for ≥ 300 mA peak (R60AFD1-V: average ≤ 100 mA, peak ≤ 300 mA). Use a supply with real current and transient headroom — not a weak LDO.
- Ground well. Radar performance drops and false-alarm rate rises with ground noise; keep the module ground solid and away from noisy loads (R60AFD1-V §9.4).
- For R24AVD1, VCC/current are not published in its getting-started guide — power it per its datasheet; only the 3.3 V I/O level is given there.
2. Serial / UART
- 115200 bps, 8 data bits, 1 stop bit, no parity, no flow control (SIP-S family; R60ABD1 manual §7; R60AFD1-V lists SIP-S V1.0).
- 3.3 V TTL levels. Cross-connect: module TX → MCU/adapter RX, module RX ← MCU TX. Never feed 5 V into the module’s RX/TX.
- Use a 3.3 V USB-TTL adapter (CP2102 / CH340); open a terminal to confirm bytes arrive after boot.
- Expect the SIP-S V1.0 frame: header
0x53 0x59… footer0x54 0x43, checksum = low 8 bits of the sum of all preceding bytes (see the parser article).
3. GPIO (if you use the hard outputs)
- R60AFD1-V GP1 / GP2 and R24AVD1 S1 / S2 are 3.3 V logic, weak (mA-level). Never connect a load directly.
- Drive a transistor/MOSFET, which switches the relay/buzzer/PLC. See Local fall alarm from GP1, GP1 → PLC dry contact, S1 → relay occupancy.
- Pin meaning: R60AFD1-V GP1 High = fall alarm, GP2 High = occupied; R24AVD1 S1 High = occupied, S2 High = active.
4. Mounting & enclosure
- Fall (R60AFD1-V): ceiling, vertical down; height 2.2–2.8 m. Set the module’s height parameter to the real height (default 2.3 m) or detection degrades.
- Presence (R24AVD1): ceiling; height ≤ 2.75 m, horizontal tilt ≤ 3°; aim the board’s long side toward the door.
- Keep the antenna 3–5 mm from a non-metal, flat enclosure face; keep the radar’s own components ≥ 1 mm above other PCBA parts (R24AVD1 guide §10).
- Keep metal out of the beam; a curved or metallized shell degrades the scan.
5. First-good-frame verification
- After power-on, wait ≥ 30 s for the module to stabilize before trusting output (R60AFD1-V §9.1).
- Confirm a repeating frame stream: header
0x53 0x59, footer0x54 0x43, and a checksum that validates. A heartbeat (control 0x01) is the easiest first sign of life. - On the fall module, check GP1 = 0 V when clear and 3.3 V on a test fall; GP2 = 3.3 V with a person in coverage.
- Before field use, set fall report time (default 15 s; normal projects ≥ 60 s) and static-dwell time (default 300 s; normal ≥ 30 min) per the datasheet.
6. Avoiding false alarms (environment)
- Keep the beam away from: oscillating fans, swinging curtains, flowing liquid, pets near the radar, and air-conditioner internal motors — aim parallel to, not at, the AC (R24AVD1 guide §11; R60AFD1-V §10).
- For presence, pick a scene mode (DP6) and sensitivity (DP5, default 7) that fits the room; lower sensitivity rejects curtain/plant sway in corridors/parking.
7. Safety
- Not a medical device. A sensing building block, not a life-safety system; not for diagnosis or treatment.
- For any high-reliability use (medical life-support, aerospace, etc.), contact the vendor first and implement fail-safe / redundant design (R60AFD1-V §11).
Where to go next
- The GPIO/UART split: GPIO vs UART.
- Decode the bytes: Minimal UART parser (SIP-S V1.0).
- Local fall alarm from GP1: relay/buzzer.
- GP1 → PLC dry contact: opto-isolated.
- S1 → relay occupancy: lighting/HVAC.
- Full specs: Module spec sheet.
- Tuning: Fall radar guide, Presence radar guide.
Evaluation units are on Tindie.