multi-voltage dual USB UART

This is a CP2105 based dual-port USB UART.

As a very special feature, this device allows you to manually select the UART voltage levels to 1.8, 2.3, 2.5, 2.8, 3.0 or 3.3 Volts.

It is thus ideal for a lab environment, where you frequently need to interconnect with various embedded electronics devices that have UARTs at unusual voltages.

Both UART ports feature RxD/TxD/RTS/CTS signals and have TVS diodes for ESD protection.

Miscellaneous CP2105 GPIOs are available on a separate header


Design Files / Schematics / Layour

The EAGLE design files for this open hardware project are available in the osmocom-small-hardware.git repository and can be checked out using
git clone git://

PDF renderings of schematics and component placement are attached below.

schematics rendered as png


A fully assembled circuit board can be obtained from

mv-uart-front.jpg (68.2 KB) laforge, 11/25/2016 04:18 PM

mv-uart-back.jpg (59.9 KB) laforge, 11/25/2016 04:18 PM

mv-uart.pdf (35.2 KB) laforge, 11/25/2016 04:19 PM

mv-uart_brd.pdf (19.9 KB) laforge, 11/25/2016 04:19 PM

mv-uart.png - schematics rendered as png (179 KB) laforge, 11/25/2016 09:04 PM