UMS1: USB-Serial Converter


The best way to USB

UMS1 (now marked UMS1B) is an USB->Serial interface module based on the FT232BL chip made by FTDI. It enables very easy connection of the user's application to the PC via the USB port, without necessity of any deep knowledge about the complicated USB problematics.

On the USB side of UMS1 there are 2 signals D+ and D-, on the opposite side there are the serial port signals (in the TTL level) with full data flow control. UMS1 is capable to transfer data at speeds up to 3000 kBaud. UMS1 supports the external EEPROM (93C46) storing the ID data (VID, PID, ID string).

UMS1 is manufactured as a DIP24 device with standard pin distance of 2.54 mm (0.1"). It can be put into standard or precision DIP socket or it can be directly soldered to user application PCB. It saves time and money in small series production.

The USB connector is to be connected separately, the designer has flexibility in the PCB layout and mechanical design in comparison to modules with built-in USB connector. Also, the A-type, B-type connector or even cable can be used.

Great advantage of FTDI based USB solution is that the drivers are freely available on the Internet. The supported operating systems are Windows 98SE/ME/2K/XP, Mac and Linux. The software examples for Borland Delphi and C++ Builder and Microsoft Visual C++ and Visual Basic are available, too. There are two types of drivers - Virtual COM port (emulates the standard COM port, the accessibility is via standard COM functions) and direct drivers with functions such as FT_Open, FT_Close, FT_ResetDevice, FT_Write, FT_Read, FT_GetStatus, FT_SetBaudRate, FT_SetFlowControl, FT_SetDTR, FT_ClrDTR, ...

When starting with USB experiments, it is useful to combine UMS1 module and UDS1 development kit.


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Supported devices

  • Any microcontroller with UART interface, e.g. PIC16F62x, PIC16F87x, PIC16F7x
  • Any programmable logic device capable of implementing asynchronous serial communication function


  • Based on FTDI chip FT232BL
  • DIP24, standard pin size
  • Ideal solution for development and small series production
  • Low cost
  • Free drivers: Windows 98SE/ME/2K/XP, Mac and Linux
  • Free software examples with source code downloadable from Internet
  • RoHS compliant


  • UMS1 module


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