Portable Meshtastic Node - XIAO nRF52840 & Wio-SX1262

Compact cylindrical portable node for Meshtastic network. Design optimized for portability and 10-20 days battery life.

For experienced makers - Requires soldering, wiring, and custom firmware flashing.

📐 Specifications

• Size: Ø52mm × 110mm (without antenna)
• Weight: 175g (1 battery) / 220g (2 batteries)
• Battery life: ~10 days (1×18650) / ~20 days (2×18650)
• Kit: XIAO nRF52840 & Wio-SX1262 with custom firmware
• Display: OLED 1.3" I2C
• Sensors: INA219 (battery) + AHT20+BMP280 (environment)
• Charging: TP4056 USB-C
• Antenna: SMA 868MHz 6dBi recommended

🎯 Features

✅ Single-file 3D printable design

✅ Serviceable (unscrew bottom cap + remove cover)

✅ 1 or 2 battery configuration

✅ Complete telemetry (battery + temperature/humidity/pressure)

✅ Integrated threaded posts for component mounting

📦 Files

• nodo_portatile.stl - Universal STL
• nodo_portatile.3mf - Pre-configured for direct printing

🛠️ Bill of Materials

Electronics: XIAO nRF52840 & Wio-SX1262 Kit • OLED 1.3" I2C • INA219 • AHT20+BMP280 • TP4056 USB-C • 1-2× 18650 batteries • Battery holder plates • SMA female connector • 2× Ø7mm panel buttons • 868MHz antenna • uFL-SMA cable • 10kΩ resistor (MANDATORY for D0)

Hardware: 4× M2.5 screws • 6× M2 screws • 2× M3 screws • Wire • Hot glue • Heat shrink

🖨️ 3D Printing

• Material: PLA (PETG/ASA for strength)
• Layer: 0.2mm, Infill: 20-30%
• Supports: For SMA connector and display window

.3mf file includes optimal orientation and support settings.

📡 Custom Firmware - REQUIRED

Download: https://tntfiles.com/l4nasxug9r/seeedstudio-xiao-nrf-52840-i2c-meshtastic-firmware

Version: Meshtastic v2.7.14 with I2C on D6/D7 (instead of default pins)

Flash: Double-click RESET button → drag .uf2 file to USB drive → auto reboot

🔧 Assembly - Critical Steps

⚠️ ANTENNA WARNING

ALWAYS connect complete antenna (external + uFL cable) BEFORE powering! ❌ Powering without antenna = permanent LoRa chip damage

Key Assembly Points

1. Component prep: Solder all cables before assembly. Display cables go UNDER PCB (not on top)
2. Top assembly: Install buttons (Ø7mm), SMA connector, TP4056 (hot glue)
3. Join top+body: Snap-fit + secure with 2× M3 screws (permanent)
4. Electronics: Mount INA219 (4× M2.5), display (4× M2), sensor (2× M2), press-fit kit
5. Wiring: I2C bus on D6/D7 • Power: TP4056→INA219→Kit

• 🔴 CRITICAL - D0 Button: Twist button wires together
• Connect: one to D0, other to GND directly from board (not shared junction)
• MANDATORY: Solder 10kΩ resistor between D0 and 3.3V
• Without these: button will fail after 2-12 hours!

1. Antenna: Screw external antenna → connect uFL cable to Wio-SX1262
2. Power up: Insert batteries (node powers on) or test via USB first
3. Close: Insert cover + screw bottom cap

🔋 Battery Options

Standard (220g): 2× 18650 parallel = ~20 days

Light (175g): 1× 18650 = ~10 days (ideal for hiking)

💡 Critical Notes

🔴 Display cables: MUST be under PCB

🔴 D0 Button stability: Requires twisted cables + dedicated GND + 10kΩ pull-up (see assembly step 6)

🔴 Antenna: Mount BEFORE any power connection

🔴 Kit power: Solder VCC/GND before press-fitting (wires stay between boards)

Sensor hole: Optional breathable fabric inside cover for dust protection while maintaining airflow.

🔓 Maintenance

Access: Unscrew bottom cap → remove cover → direct access to kit and batteries

Reprogram: Connect USB-C to kit

Battery swap: Remove via bottom opening

📄 License

CC BY-NC-SA 4.0 (Creative Commons Attribution-NonCommercial-ShareAlike)

✅ Personal use, modify, share modifications

❌ Commercial use prohibited

Attribution required

🎯 For Makers Who

• Want customizable Meshtastic nodes
• Have soldering/wiring skills
• Prefer DIY over commercial plug & play
• Appreciate open source hardware

Not for: Ready-to-use seekers without assembly skills