ET-C20
CH340C USB-UART Adapter 5 V
5 V logic USB-C serial with Arduino auto-reset
AED 49.00
Out of stock✓ TestedEvery board is checked before it ships
🚚 Fast shippingUAE 1–3 days · GCC & worldwide
💬 Engineer supportQuestions answered by the designers
Overview
5 V logic USB-C serial with Arduino auto-reset
The ET-C20 is built around the WCH CH340C at 5V — TX/RX/DTR/RTS 5V logic, up to 2Mbps.
Designed in Dubai by ElectroTrical — the full schematic, BOM and design notes are published below.
Good for
- Programming Arduino Pro Mini
- Bare ATmega boards
- 5 V serial devices
Key features
What makes it different
Bridge
WCH CH340C at 5V: TX/RX/DTR/RTS 5V logic, up to 2Mbps
Arduino
FTDI-style pinout with DTR auto-reset cap — programs Pro Mini / bare ATmega boards
Power
VBUS 5V + 3.3V aux on the header
Open documentation
Schematic, BOM and layout notes published for every board.
Breadboard friendly
Standard 2.54 mm pitch and M2.5 mounting holes.
Specifications
Technical specifications
| Bridge | WCH CH340C at 5V: TX/RX/DTR/RTS 5V logic, up to 2Mbps |
|---|---|
| Arduino | FTDI-style pinout with DTR auto-reset cap — programs Pro Mini / bare ATmega boards |
| Power | VBUS 5V + 3.3V aux on the header |
| Size | 25.4 × 17.8 mm |
|---|---|
| Mounting | 2 mounting holes (M2.5) |
| Connectors | 7-pin 2.54 mm header · USB-C 16P receptacle (USB 2.0) — USB-C |
| Main IC | CH340C (LCSC C84681) |
| Revision | Rev A |
Performance
Speed
Pinout
Pin map and connections
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VBUS | Power | 5V |
| 2 | GND | Ground | Ground |
| 3 | 3V3 | Power | Aux 300mA |
| 4 | TX | UART | 5V logic |
| 5 | RX | UART | 5V logic |
| 6 | DTR | UART | Via 100nF → Pro Mini RESET |
| 7 | RTS | UART | Active low |
Mechanical
Dimensions and what's in the box
In the box
- 1 × ET-C20 CH340C USB-UART Adapter 5 V (assembled)
- 1 × 7-pin 2.54 mm male header, unsoldered
Getting started
- Wire the header: VBUS, GND, 3V3, TX, RX, DTR
Compare
Which USB adapter?
| CH340C USB-UART Adapter 5 V (this board)This board | ET-C12 USB-C to I²C / Qwiic Adapter | ET-C13 CP2102N USB-UART Adapter | ET-C03 USB-C to UART Adapter | |
|---|---|---|---|---|
| What it does | 5 V logic USB-C serial with Arduino auto-reset | Talk to Qwiic sensors from a PC — no driver needed | 3 Mbps USB-C serial adapter with flow control, 3.3 V | CH340C serial adapter with 3.3 V logic |
| Interface | — | — | — | — |
| Best for | Programming Arduino Pro Mini | Testing sensors from Python | Flashing ESP32 and STM32 | Debug consoles |
| Price | 49 AED | 20 AED | 19 AED | 27 AED |
Downloads
Documents and design files
Need a custom version of this board?
Different connector, size or sensor? We design and build custom variants.