This serial data interface based on the FTDI USB to RS232
converter allows direct connection from a PC to an embedded processor
with logic level and polarity
compatibility. This is especially useful when debugging serial communications
directly from the target processor as well as allowing the elimination
of RS232 buffering logic where the serial interface is used only for
programming and calibration, but not intended for end user access.
- Embedded processor logic polarity: Inactive state is logic high, start bit is logic
low (RS232 from PC is inverted).
- Logic voltage range is set by the level at VIO
(Pin-10) and can range from 1.8V to 5.5V. Leave the jumper out when using an externally supplied
interface voltage.
- Internal 3.3V (10mA) and 5.0V (50mA) supplies can
be used externally and are present at VIO (Pin-10) when the jumper is
installed in one of the two positions.
- The FTDI
VCP
(Virtual Com Port) or
D2XX
(Direct Driver) drivers are available from the
FTDI website for
most operating systems. The VCP driver makes the serial interface look like a
standard COM port and is the first choice for most users. When
it enumerates, the USB driver selects the next free port number which
is keyed to the serial number of the FTDI chip and the physical port
it was plugged into, to
change the port setting to a specific one in Windows, go to the
hardware manager and force it to the number desired (Provided the new
number is actually a currently free port!).
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