ET-M09
ESP32-C3 Battery Dev Board
Wi-Fi/BLE board with LiPo charger, power path and battery monitor
AED 22.00
Out of stockOverview
Wi-Fi/BLE board with LiPo charger, power path and battery monitor
The ET-M09 is built around the ESP32-C3-MINI-1-N4 — RISC-V 160MHz, Wi-Fi 4, BLE 5, 4MB flash.
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
- Battery sensor nodes
- Portable BLE gadgets
- Solar-topped weather stations
Key features
What makes it different
MCU
ESP32-C3-MINI-1-N4: RISC-V 160MHz, Wi-Fi 4, BLE 5, 4MB flash
Battery
1-cell LiPo on JST-PH, MCP73831 500mA charger, charge LED
Power path
USB present: runs from USB via Schottky; battery isolated by P-MOSFET. USB absent: battery → LDO.
Monitor
Battery voltage ÷2 on IO0 (ADC)
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 | ESP32-C3-MINI-1-N4: RISC-V 160MHz, Wi-Fi 4, BLE 5, 4MB flash |
|---|---|
| Battery | 1-cell LiPo on JST-PH, MCP73831 500mA charger, charge LED |
| Power path | USB present: runs from USB via Schottky; battery isolated by P-MOSFET. USB absent: battery → LDO. |
| Monitor | Battery voltage ÷2 on IO0 (ADC) |
| Deep sleep | ≈10µA chip + ≈55µA AP2112K + divider 21µA (cut LED when battery-powered) |
| Size | 50.8 × 22.9 mm |
|---|---|
| Mounting | 4 × M2.5 holes, 2.54 mm from each corner |
| Connectors | 2 × Qwiic / STEMMA QT (JST SH 4-pin) · 15-pin 2.54 mm header · USB-C 16P receptacle (USB 2.0) — USB-C (power + native USB / bridge) · JST PH 2P R/A SMD (LiPo) — LiPo battery |
| Main IC | ESP32-C3-MINI-1-N4 (LCSC C2838502) |
| Revision | Rev A |
| Libraries | Arduino-ESP32, ESP-IDF, ESPHome (battery sensor template included) |
|---|
Performance
Battery life
Pinout
Pin map and connections
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VSYS | Power | USB 5V or battery |
| 2 | 3V3 | Power | 600mA LDO |
| 3 | GND | Ground | Ground |
| 4 | EN | Control | Reset / power-off, active low |
| 5 | VBAT | Power | LiPo + |
| 6 | IO1 | GPIO | ADC1_1 |
| 7 | IO2 | GPIO | ADC1_2, strap |
| 8 | IO3 | GPIO | ADC1_3 |
| 9 | IO4 | GPIO | ADC1_4 |
| 10 | IO5 | GPIO | ADC2 |
| 11 | SDA | I²C | IO6 — I2C SDA |
| 12 | SCL | I²C | IO7 — I2C SCL |
| 13 | IO8 | GPIO | Strap (pull-up) |
| 14 | IO20 | GPIO | RX0 |
| 15 | IO21 | GPIO | TX0 |
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-M09 ESP32-C3 Battery Dev Board (assembled)
- 1 × 15-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-ESP32, ESP-IDF, ESPHome (battery sensor template included)
Compare
Which ESP32 board?
| ESP32-C3 Battery Dev Board (this board)This board | ET-M01 ESP32-C3 Mini Dev Board | ET-M02 ESP32-S3 Dev Board | ET-M03 ESP32-C6 Thread / Zigbee Board | |
|---|---|---|---|---|
| What it does | Wi-Fi/BLE board with LiPo charger, power path and battery monitor | Wi-Fi + BLE 5 RISC-V board with native USB-C and a Qwiic port | Dual-core 240 MHz, 8 MB flash, USB OTG and Qwiic | Wi-Fi 6, BLE and 802.15.4 (Thread, Zigbee, Matter) |
| Interface | — | — | — | — |
| Best for | Battery sensor nodes | Small Wi-Fi sensors and ESPHome nodes | USB keyboards and MIDI devices (TinyUSB) | Matter and Thread smart-home devices |
| Price | 22 AED | 29 AED | 49 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.