Hardware components for building the OpenFlight golf launch monitor.
Next step after gathering parts: See the Raspberry Pi Setup Guide for assembly and software installation.
| Part | Description | Link | ~Price |
|---|---|---|---|
| OPS243 Radar | Doppler radar for ball/club speed detection | OmniPreSense | $249 |
| Raspberry Pi 5 | Main compute unit (4GB+ recommended) | Adafruit | $130 |
WARNING: Do NOT buy the OPS243-A-W (WiFi version). The WiFi module locks the serial baud rate to 19200, which is far too slow for I/Q data transfer. OpenFlight requires the standard OPS243 (USB only) which runs at 57600 baud over CDC-ACM. The WiFi version is not compatible. | 7" Touchscreen Display | HMTECH 7" 1024x600 IPS display | Amazon | $46 |
Display alternative: The Raspberry Pi Touch Display 2 (7" 720x1280, MIPI DSI) also works with the Pi 5. If you use it, print the
Touch_Display2_backplate.stlandTouch_Display2_shell.stlfrom the IARC case instead ofmonitor_shell.stl— see the IARC case instructions.
The sound trigger detects club impact to precisely time radar captures. Essential for spin detection via rolling buffer mode.
| Part | Description | Link | ~Price |
|---|---|---|---|
| SparkFun SEN-14262 | Sound Detector with envelope/gate outputs | SparkFun | $12 |
| Through-hole resistor | For R17 pad on SEN-14262 to reduce sensitivity (see note) | Any electronics supplier | $1 |
| Jumper Wires | 3 wires: GATE → HOST_INT, VCC → 3.3V, GND → GND | Any | $5 |
R17 resistor: The SEN-14262 is rated for 5V but runs at 3.3V in this setup, which can cause the GATE output to stick high. Soldering a resistor into the R17 through-hole position (in parallel with the onboard 100kΩ R3) reduces preamp gain and fixes this. Start with 47kΩ; use a lower value (e.g. 33kΩ) if the sensor is still too sensitive for your environment.
SEN-14262 Raspberry Pi OPS243
┌───────────┐ ┌──────────┐ ┌──────────┐
│ VCC ──────┼──────────┤ 3.3V │ │ │
│ │ │ │ │ │
│ GATE ─────┼──────────┼──────────┼──────────┤ HOST_INT │
│ │ │ │ │ (J3 P3) │
│ GND ──────┼──────────┤ GND ├──────────┤ GND │
│ │ │ │ │ (J3 P1) │
└───────────┘ └──────────┘ └──────────┘
See sound-trigger-wiring.md for detailed instructions and troubleshooting.
This is the supported angle radar. It measures vertical and horizontal launch angle, and supplies the pre-impact frames club path is derived from.
| Part | Description | Link | ~Price |
|---|---|---|---|
| TI IWR6843LEVM | 60 GHz mmWave evaluation board, 4 RX × 3 TX | TI | $150 |
| USB cable (data-capable) | Connects the LEVM's CP2105 serial bridge to the Pi. Charge-only cables will not enumerate — check the connector on your board revision | Any | $5 |
| Jumper wire | 1 wire: detector GATE → Pi BCM17 / physical pin 11, alongside the existing GATE → OPS HOST_INT |
Any | $1 |
The board needs custom firmware — it does not work out of the box. The
stock TI demo does not expose the raw radar cube OpenFlight needs. A validated
prebuilt image ships in firmware/releases/, so you do not need the TI
toolchain to flash it.
You also need physical access to the board's boot-mode switch (S1.1) and RESET button to flash. Both are on the LEVM itself; nothing to buy.
Two connection layouts are supported, and which one you can use depends on your OPS243 variant:
| Layout | OPS243 connection | Extra parts needed |
|---|---|---|
| A (validated) | Pi GPIO UART header | 4 jumper wires (5V, GND, TX, RX) |
| B | Powered USB hub | Powered USB hub (~$20) |
Layout A keeps the TI board on USB and moves the OPS243 to the Pi's GPIO header, which is what the power budget requires — the Pi cannot supply both radars over USB.
Warning
Layout A does not work with a WiFi-equipped OPS243-A. Its onboard WiFi module already drives the radar's UART receive line, so the Pi cannot send it commands. WiFi OPS boards must use Layout B with a powered hub.
Full instructions: IWR6843 Operator Guide for wiring, flashing, mounting, and geometry; Moving the OPS243 to the Pi GPIO UART for the OPS side of Layout A.
⚠️ DEPRECATED — do not buy for new builds. The K-LD7 angle radars have been superseded by a more capable radar chip. K-LD7 support remains in the software for existing builds but will not receive further development. The parts below are listed for reference only.
Two K-LD7 modules measure launch angle (vertical) and club path / aim direction (horizontal). The OPS243 handles speed; the K-LD7s provide angle and distance only (speed data aliases above 62 mph).
| Part | Description | Link | ~Price |
|---|---|---|---|
| RFbeam K-LD7 (×2) | 24 GHz FMCW radar for angle + distance | RFbeam | ~$60 ea |
| FTDI USB-to-Serial adapter (×2) | 3.3V FTDI board for K-LD7 UART (e.g. FT232RL) | Amazon | ~$10 |
EVAL board not required. The K-LD7 bare module communicates over 3.3V UART (TX, RX, VCC, GND). Any 3.3V FTDI USB-to-serial adapter works. The official K-LD7 EVAL board (~$120 each) is only needed if you want the RFbeam GUI software for configuration — OpenFlight configures the radar over serial automatically.
Each K-LD7 connects via a 3.3V FTDI adapter, appearing as /dev/ttyUSB* on Linux.
K-LD7 Module (UART) → FTDI 3.3V Adapter → USB → Raspberry Pi
One unit is mounted vertically (launch angle), one horizontally (club path / aim direction). A --kld7-angle-offset parameter corrects for mounting geometry — see the setup guide for calibration.
| Part | Description | Link | ~Price |
|---|---|---|---|
| 27W USB-C Power Supply | Official Pi 5 power supply (5V 5A) | Adafruit | $14 |
| MicroSD Card (32GB+) | For Pi OS and software | Any Class 10 | $10 |
| USB-A to Micro-USB Cable | For OPS243 radar connection | Any | $5 |
| Part | Description | Link | ~Price |
|---|---|---|---|
| Tripod Mount | For positioning the unit | 1/4"-20 mount | $10 |
| Category | ~Price |
|---|---|
| Core (OPS243, Pi 5, Display) | $355 |
| Sound Trigger (SEN-14262 + resistor + wires) | $18 |
| Power & Accessories | $27 |
| Subtotal, no angle radar | ~$400 |
| Angle Radar (IWR6843LEVM + cable + wire) — current | $156 |
| Total with angle radar | ~$556 |
| Angle Radar (2× K-LD7 + FTDI adapters) — deprecated | $140 |
OpenFlight works without any angle radar: you get ball speed, club speed, smash factor, spin rate, and estimated carry. The angle radar adds measured launch angle (vertical and horizontal) and is what club path is derived from.
If you are building new, buy the IWR6843, not the K-LD7s. It costs about the same as the two K-LD7s plus their FTDI adapters ($156 vs $140) and replaces both of them with one board. The K-LD7 path is deprecated and kept only so existing builds keep working.