ET-M14
nRF52840 BLE Board
Nordic nRF52840 module with native USB-C, SWD and Qwiic
AED 29.00
Out of stockOverview
Nordic nRF52840 module with native USB-C, SWD and Qwiic
The ET-M14 is built around the Nordic nRF52840 (Ebyte E73-2G4M08S1C) — Cortex-M4F 64MHz, 1MB flash, 256KB RAM, BLE 5 / 802.15.4 / ANT, native USB.
Two Qwiic / STEMMA QT connectors let you chain it with other boards without soldering, and the 2.54 mm header fits a breadboard.
Designed in Dubai by ElectroTrical — the full schematic, BOM and design notes are published below.
Good for
- BLE wearables and keyboards
- Zephyr / nRF Connect projects
- Low-power wireless sensors
Key features
What makes it different
MCU
Nordic nRF52840 (Ebyte E73-2G4M08S1C): Cortex-M4F 64MHz, 1MB flash, 256KB RAM, BLE 5 / 802.15.4 / ANT, native USB
USB
USB-C to the nRF52840 USB device (after installing a UF2 bootloader)
I/O
14 GPIO + 8 analog-capable on the header, SWD header, Qwiic at 3.3V
Power
5V USB-C → AP2112K 3.3V; module VBUS sensed for USB detect
Qwiic / STEMMA QT
Two JST-SH connectors plus a 2.54 mm header — 3.3 V and 5 V hosts.
Open documentation
Schematic, BOM and layout notes published for every board.
Specifications
Technical specifications
| MCU | Nordic nRF52840 (Ebyte E73-2G4M08S1C): Cortex-M4F 64MHz, 1MB flash, 256KB RAM, BLE 5 / 802.15.4 / ANT, native USB |
|---|---|
| USB | USB-C to the nRF52840 USB device (after installing a UF2 bootloader) |
| I/O | 14 GPIO + 8 analog-capable on the header, SWD header, Qwiic at 3.3V |
| Power | 5V USB-C → AP2112K 3.3V; module VBUS sensed for USB detect |
| Size | 45.7 × 25.4 mm |
|---|---|
| Mounting | 4 × M2.5 holes, 2.54 mm from each corner |
| Connectors | 2 × Qwiic / STEMMA QT (JST SH 4-pin) · 20-pin 2.54 mm header · USB-C 16P receptacle (USB 2.0) — USB-C (power + native USB / bridge) |
| Main IC | E73-2G4M08S1C (LCSC C356849) |
| Revision | Rev A |
| Libraries | Arduino (Adafruit nRF52 core), CircuitPython, Zephyr / nRF Connect SDK, Rust embassy-nrf |
|---|
Performance
Power use
Pinout
Pin map and connections
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VBUS | Power | 5V from USB-C |
| 2 | 3V3 | Power | 600mA LDO |
| 3 | GND | Ground | Ground |
| 4 | RESET | Control | Reset (P0.18), active low |
| 5 | P0.02 | Signal | AIN0 |
| 6 | P0.03 | Signal | AIN1 |
| 7 | P0.04 | Signal | AIN2 |
| 8 | P0.05 | Signal | AIN3 |
| 9 | P0.28 | Signal | AIN4 |
| 10 | P0.29 | Signal | AIN5 |
| 11 | P0.30 | Signal | AIN6 |
| 12 | P0.31 | Signal | AIN7 |
| 13 | P0.06 | UART | UART TX |
| 14 | P0.08 | UART | UART RX |
| 15 | P0.13 | Signal | SPI SCK |
| 16 | P0.14 | Signal | SPI MOSI |
| 17 | P0.16 | Signal | SPI MISO |
| 18 | P0.20 | Signal | GPIO / NFC-free |
| 19 | SDA | I²C | P0.12 — I²C SDA (Qwiic) |
| 20 | SCL | I²C | P0.11 — I²C SCL (Qwiic) |
Qwiic / STEMMA QT pins: GND, VIN, SDA, SCL (same on both connectors).
Mechanical
Dimensions and what's in the box
In the box
- 1 × ET-M14 nRF52840 BLE Board (assembled)
- 1 × 20-pin 2.54 mm male header, unsoldered
Getting started
- Plug in a Qwiic / STEMMA QT cable, or solder the header and wire VIN, GND, SDA and SCL
- Libraries: Arduino (Adafruit nRF52 core), CircuitPython, Zephyr / nRF Connect SDK, Rust embassy-nrf
Compare
Which wireless board?
| nRF52840 BLE Board (this board)This board | ET-M13 ESP32-H2 Thread / Zigbee Board | ET-M17 ESP8266 Wi-Fi Board | ET-M03 ESP32-C6 Thread / Zigbee Board | |
|---|---|---|---|---|
| What it does | Nordic nRF52840 module with native USB-C, SWD and Qwiic | BLE 5 + Thread / Zigbee / Matter, no Wi-Fi, low power | ESP-12F with one-click USB-C upload and Qwiic | Wi-Fi 6, BLE and 802.15.4 (Thread, Zigbee, Matter) |
| Interface | — | — | — | — |
| Best for | BLE wearables and keyboards | Battery Zigbee sensors | Tasmota and ESPHome switches | Matter and Thread smart-home devices |
| Price | 29 AED | 29 AED | 25 AED | 28 AED |
Downloads
Documents and design files
Need a custom version of this board?
Different connector, size or sensor? We design and build custom variants.