Uploaded December 2025 | Updated September 2026, 2 weeks ago

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Meshtastic is an open-source, decentralized communication network built on LoRa technology. In my previous video, I set up two Meshtastic nodes using the XIAO nRF52840 and Wio-SX1262 Kit. In the second video, I upgraded them by enabling I2C support and adding the Telemetry module to report temperature and barometric pressure from a BMP280 sensor. To enable I2C, I recompiled the Meshtastic firmware for the XIAO nRF52840 and Wio-SX1262 Kit from source. This also made it possible to connect a mini OLED display. I used a yellow-blue 0.96″ SSD1306 I²C OLED display that operates at 3.3 V, wiring SDA to D6 and SCL to D7 on the XIAO nRF52840, instead of the default hardware I²C pins, as defined in the Meshtastic firmware configuration.

To compile the Meshtastic firmware from source with I2C support for the XIAO nRF52840 and Wio-SX1262 Kit have a look at my other related video:
youtu.be/zhS_2MZbjzM?si=Mg-hwTyip0chQt7W

🔌 SSD1306 Wiring for Meshtastic Firmware on XIAO nRF52840 and Wio-SX1262
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GND to GND of XIAO nRF52840
VCC to 3.3V of XIAO nRF52840
SDA to D6 of XIAO nRF52840
SCL to D7 of XIAO nRF52840

NOTE: this wiring is specific for the Meshtastic firmware built using the configuration seeed_xiao_nrf52840_kit_i2c

🎥 Related Videos
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Getting Started with Meshtastic: XIAO nRF52840 & Wio-SX1262 Setup and First Test
youtu.be/lOhg--tFEUg?si=8g-44pyJYJE6kJ13

Custom Meshtastic Firmware: Add I2C and BMP280 Sensor Telemetry on XIAO nRF52840 & Wio-SX1262
youtu.be/zhS_2MZbjzM?si=Mg-hwTyip0chQt7W

🔗 Useful Links
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github.com/meshtastic/firmware
Meshtastic Firmware Build Configurations for XIAO nRF52840 & Wio-SX1262 Kit
github.com/meshtastic/firmware/blob/develop/variants/nrf52840/seeed_xiao_nrf52840_kit/platformio.ini
Meshtastic Firmware Pin Configurations for XIAO nRF52840 & Wio-SX1262 Kit
github.com/meshtastic/firmware/blob/develop/variants/nrf52840/seeed_xiao_nrf52840_kit/variant.h
BMP280 in Meshtastic Firmware
github.com/meshtastic/firmware/blob/develop/src/modules/Telemetry/Sensor/BMP280Sensor.cpp
XIAO nRF52840 & Wio-SX1262 Kit
wiki.seeedstudio.com/xiao_nrf52840&_wio_SX1262_kit_for_meshtastic
XIAO nRF52840 & Wio-SX1262 Kit for Meshtastic
seeedstudio.com/XIAO-nRF52840-Wio-SX1262-Kit-for-Meshtastic-p-6400.html
Getting Started with the Meshtastic Kit: XIAO nRF52840 & Wio-SX1262
anavi.org/article/334
Attaching a Mini I2C SSD1306 OLED Display to Meshtastic Kit with XIAO nRF52840 and Wio-SX1262
anavi.org/article/341


📚 Chapters
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0:00 Intro
0:46 Enable I2C
3:34 Wiring
4:54 Config
7:28 Demo
9:16 Advantages
9:31 Disadvantages
10:26 Conclusions