Documentation
Onboarding
Getting Started
Power & Battery
Hardware & Components
Build & Assembly
Radio & RF Design
Frequencies & Regulations
Firmware & Software
USB & Connectivity
GPS & Navigation
Morse & Communication
Modes & Operation
Field Operations & Rescue
Building Effectively
Build Variants
Project & Reference
Docs Build & Assembly Assembly Guide

Assembly Guide

Edit on GitHub

Complete step-by-step build: soldering order, wiring, mounting and first power-up of the beacon

Assembly Guide

Warning

This guide assumes basic SMD soldering skills. If you’re new to soldering, practice on scrap boards first.

Prerequisites

Tools Required

  • Soldering iron (25-40W, fine tip)
  • Solder (60/40 or lead-free)
  • Flux (rosin or no-clean)
  • Multimeter
  • Wire strippers
  • Hot glue gun (optional)

Components

See Hardware Components for complete BOM.

Step 1: Prepare ESP32 DevKit

  1. Inspect board for damage
  2. Test USB connection: Tools → Port should show COM port
  3. Flash test firmware to verify operation

Tip

Flash firmware first to ensure ESP32 is working before assembly.

Step 2: Install SX1262 Module

Pin Connections

E22 PinESP32 GPIOWire Color
VCC3V3Red
GNDGNDBlack
SCKGPIO 18Yellow
MISOGPIO 19Orange
MOSIGPIO 23Green
NSSGPIO 5Blue
RESETGPIO 14Purple
BUSYGPIO 21White

Important

BUSY (GPIO 21) is mandatory. Without it, firmware will hang on first radio call.

Soldering Order

  1. Solder VCC and GND first
  2. Verify 3.3V on VCC pin (never 5V!)
  3. Solder SPI pins (SCK, MISO, MOSI, NSS)
  4. Solder control pins (RESET, BUSY)
  5. Test SPI communication

Step 3: Install OLED Display

Pin Connections

OLED PinESP32 GPIOWire Color
GNDGNDBlack
VCC3.3VRed
SCKGPIO 15Yellow
SDAGPIO 13Green
RESGPIO 4Purple
DCGPIO 16Blue
CSGPIO 17Orange

Mounting

  1. Position OLED on enclosure front panel
  2. Secure with hot glue or mounting clips
  3. Route cables to ESP32

Step 4: Install GPS Module (Optional)

Pin Connections

GPS PinESP32 GPIOWire Color
VCC3.3VRed
GNDGNDBlack
TXGPIO 22White
RXN/CYellow (leave unconnected)

Antenna Placement

  • Mount ceramic patch antenna facing up
  • Keep away from battery and metal
  • Route antenna wire through enclosure

Step 5: Battery System

TP4056 Charger

  1. Mount TP4056 module near USB port
  2. Connect USB-C connector to enclosure
  3. Route BAT+ and BAT- to battery holder

Battery Holder

  1. Mount 18650 holder in enclosure
  2. Connect spring contacts to TP4056
  3. Ensure polarity is correct

Voltage Divider

CODE
BAT+ --> R3a (100k) --> Junction --> R3b (100k) --> GND
                         |
                     GPIO 36

Warning

GPIO 36 is input-only. No external pullup needed.

Step 6: Audio Output

Components

  • R2: 100 Ohm series resistor
  • C3: 10uF electrolytic (AC coupling)
  • J1: 3.5mm TRRS jack

Connections

CODE
GPIO 25 --> R2 (100R) --> C3 (+) --> C3 (-) --> Jack TIP
                                         |
                                         GND --> Jack SLEEVE

Jack Wiring

Jack PinConnection
Tip (L audio)From C3
Ring 1 (R)Tie to Tip (mono)
Ring 2 (MIC)Not connected
Sleeve (GND)Ground

Step 7: Button Panel

Mounting

  1. Drill holes in enclosure for 6x6mm switches
  2. Mount switches on PCB or panel
  3. Route wires to ESP32

Connections

ButtonESP32 GPIOPullup
MODEGPIO 33Internal
SELGPIO 32Internal
UPGPIO 35External 10k
DNGPIO 34External 10k

Note

GPIO 34 and 35 are input-only. External 10k pullup resistors required.

Step 8: LED Indicators

Red LED (BEACON)

CODE
GPIO 27 --> 330R --> Red LED anode --> Cathode --> GND
CODE
GPIO 26 --> 330R --> Blue LED anode --> Cathode --> GND

Mounting

  • Drill 3mm holes in enclosure
  • Mount LEDs with hot glue
  • Route wires to ESP32

Step 9: Antenna

Wire Antenna

  1. Cut 17.3cm of solid copper wire
  2. Strip 5mm from one end
  3. Solder to ANT pad on E22 module
  4. Route wire through enclosure

SMA Connector

  1. Mount SMA bulkhead connector
  2. Connect to E22 SMA output
  3. Attach whip antenna

Tip

Never transmit without antenna connected. This can damage the power amplifier.

Step 10: Final Assembly

Enclosure Preparation

  1. Drill holes for:
    • USB-C port
    • Audio jack
    • SMA connector
    • Buttons (4x)
    • LEDs (2x)
    • OLED window
  2. Mount standoffs for ESP32

Component Placement

  1. Mount ESP32 on standoffs
  2. Position OLED on front panel
  3. Install battery holder
  4. Route all cables neatly
  5. Secure with hot glue where needed

Testing

  1. Power on via USB
  2. Verify OLED display
  3. Test button functions
  4. Check radio transmission
  5. Verify audio output
  6. Test GPS (if installed)

Tip

Perform a range test after assembly. Walk away with AM receiver and note maximum audible distance.

Troubleshooting

IssueSolution
No displayCheck SPI connections, verify GPIO 4 reset
Radio hangsVerify BUSY pin (GPIO 21) connected
No audioCheck GPIO 25, verify 10uF cap orientation
Buttons unresponsiveCheck pullups on GPIO 34/35
GPS not fixingMove outdoors, check UART2 connections
Low battery readingVerify voltage divider, adjust BAT_VREF_MV