Wire and Connectors
Edit on GitHubWire gauge, jumper types, and the connectors used across the beacon build.
Wire and Connectors
The beacon is small, so the wiring choices matter more than they look.
Wire gauge
- Power wires (BAT+, GND): 22-24 AWG. The radio PA bursts can draw 100+ mA; thin wire drops voltage under load.
- Signal wires (SPI, UART, buttons): 24-28 AWG is fine; the currents are microamps.
- Antenna feed: the E22 uses SMA; the internal antenna wire (17.3 cm) needs no connector.
Common wire types
- Solid core 22 AWG: great for breadboards, snaps into headers cleanly.
- Stranded 24 AWG: flexible for enclosure routing, needs tinning or ferrules.
- Silicone-insulated wire: survives soldering heat and stays flexible in cold weather; worth it for field builds.
Connectors used
| Connector | Where |
|---|---|
| SMA (E22) | Radio to external antenna |
| USB-C (TP4056) | Charging input |
| 3.5 mm TRRS | Audio out |
| Pin headers (2.54 mm) | ESP32, OLED, GPS module breaks |
| Dupont / JST-XH (optional) | Battery and sensor connections |
Recommended wiring approach
- Pre-cut and strip all wires before soldering.
- Tin the wire ends.
- Use heat shrink over every soldered joint that could touch a neighbor.
- Keep power and signal wires separated where they run parallel.
The internal antenna wire
The 17.3 cm quarter-wave wire attaches directly to the SMA center pin (or a short pigtail). Route it away from the OLED and the ESP32’s antenna area to reduce detuning.
A trap to avoid
Running the GPS antenna wire (or the patch) next to the radio’s SMA feed can desensitize the GPS. Keep at least 1-2 cm of separation, and orient the GPS patch away from the radio antenna.