Circuit diagram

This USB to Serial RS232 adapter is very useful in many situations we need to connect a device with RS232 to a computer without RS232 port , but with USB port .

Using FT232BM chip manufactured by Future Technology Devices International we can make a very simple USB to Serial RS232 adapter using few external components .
 

 

This USB to RS232 adapter based on the FT232BM driver can support many operating systems ( windows , mac, linux ) .

FT232 driver main features are : Two Individually Configurable IO Channels , Integrated Power-On Reset (POR) circuit , Integrated RCCLK circuit , Integrated level converter on UART / FIFO interface and control signals , Support for Isochronous USB Transfers , Wake Up Signal Pin on each channel , Low suspend current , Programmable Receive Buffer Timeout , USB 2.0 , Extended EEPROM Support and many other.

As you can see in the schematic bellow the circuit is very simple and the voltage needed for the circuit is obtained from the USB port .

If you are using these type of USB to RS232 adapter you need to install a driver to work