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Category: Electronics & Computers
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In this project I built a board around  FT232BL manufactured by FTDI Chip USB to Serial converter.

This converter is very useful when you want to communicate with a microcontroller or any other serial device using the USB port on your computer.

Now FT232 is arguably the best USB to Serial converter. When I was writing this article there was a newer version of this chip which had an integrated EEPROM to define PID and VID and some other characteristics of the device but I didn't need an EEPROM so I just went on with the old version which would be FT232BL.You can find the datasheet here.

This chip is a surface mount square shaped IC (LQFP Package) with 32 pins.

FTDI provides all the drivers and configuration tools you need to use this chip.

You can see the FT232BL chip in the middle.

Also I didn't use it I put an external EEPROM on the board which you can see at the bottom.

If you notice there's another IC at the upper side of the board. That's a MAX232 to convert the levels of 5V to 12V used by the computer RS232 ports. 

Schematics are available here

The circuit is quite straight forward and easy to understand. I used the 5V USB power. As you can see I used an LED which blinks with a rate relative to the speed of data transfer. The crystal is a 6MHz one as written in the datasheet.

It's written In the datasheet that you should use a ferrit bead to prevent any noise to get induced on the power line because of the high frequency of USB transmission.

I drew the ferrit bead in the schematics but if you notice I used only a wire on my PCB instead (because of my bad relationship with inductors!).

The other parts including the resistors,capacitors and the EEPROM are exactly in accordance to the datasheet.

You can find the PCB here.

 If you need the Altium Designer source files you can contact me and I'll send you the files.  

You can compare the board with my flash memory:

 Compare Size With Flash Memory

FTDI Chip provides different kinds of drivers for Windows and Linux.

I wanted to use the device as a virtual serial port so I installed Virtual COM Port (VCP) driver for Windows Vista.

After you install the driver anytime you connect the device to your USB port the OS recognizes it as a serial port and gives it a number like other serial ports. You can use this ID to send and receive data in any programming language. If you take a look at the software section of this site you can find a useful project in visual C++.