You can buy a lot of USB-UART converters e.g. with FT232, CH340 or CP2102. Each of USB-UART converters has some advantages or disadvantages.
Some doesn’t have drivers inside kernel (linux) and/or windows. Another has a problem with faster communications.
I wanted to design own USB-UART converter and so I chose another IC for convert between USB and UART.
Broads is designed for beginners as one-sided PCB with a few jumpers.
I like IC by FTDI chip company. FT230XS.
It’s in small package (16 pin SSOP or 16 pin QFN).
Data can be transfered from 300 baud up to 3 Mbaud.
It’s only USB-UART converter, not I2C, SPI or other.
It contains configurable CBUS I/O pins.
It supports USB 2.0 Full Speed.
And it’s very cheap.
This article contains two boards for USB-UART converters. The first of them is only USB-UART converter with RX, TX pin, +3.3V from internal regulator (max 50mA, but LDO supplies indication LED – TX and RX), +5V from USB and GND on pin header.
The converter contains jumper for setting VCCIO (3.3V or 5V). It means value of logic “1” on output.
Schematic:
Component placement:
PCB (600px):
The second of them is USB-UART converter which is designed for powering external components up to 500mA.
The external +3.3V LDO regulator is supplied from +5V USB.
The converter contains jumper for setting VCCIO (3.3V or 5V). It means value of logic “1” on output.
It’s suitable for connecting e.g. ESP8266, GPS and GSM module, or another module for direct connection with laptop. You don’t need another board with another power supply.
Schematic:
Component placement:
PCB (600px):
