| Frequently Asked Questions |
|
Q. What Baudrates
does the USB to TTL Cable support ?
A. The USB to TTL Cable supports the following baudrates (standard
windows baudrates are in bold):
300, 600, 1200, 1800, 2400, 4000,
4800, 7200, 9600, 14400, 16000, 19200, 28800,
38400, 51200, 56000, 57600, 64000, 768000, 115200,
128000, 153600, 230400, 250000, 256000, 500000, 576000, 921600
We can also provide custom Baudrates for specific
applications, however we reserve this option for quantity orders only.
Q. Can I connect the TTL Cable
to +3/+3.3v microcontrollers ?
A. Yes if the RX input of the microcontroller is +5v tolerant (please
check the absolute Max pin input level) otherwise the RX line voltage
should be reduced using a potential divider with values of 22k and 33k.
The threshold for the TX is such that +3v/+3.3v logic will have no problem
in transmitting. Q. My computer seems to 'hang'
when I using some software (e.g. Atmel FLIP)
A. Unfortunately this is true with our original batch of cables when
the PC software requires the use of 2 stop bits. Cable from bought
from us after
October 2005 has this issue fixed.
[Please note however that Atmel
have updated their software to run with 1 stop bit and therefore can be
used with all our cables!] Q. Do you have example software how we can get the number of the
com-port the USB2TTL uses (from registry? device manager list?) If
possible in MFC, C++ or even VB.
A. Click Here for some C and VB code
that searches the Registry for the assigned COM port number(s).
Q. Which COM port is my USB to TTL Cable ?
A. Click Here for details on how to
find the Com Port Number
Q. Can
I change the COM Port that Windows Assigns to my USB to TTL Cable ?
A. Yes, Click Here for details on how to change the Com Port Number.
Q.
During the installation of the device
I get the following error:
"cannot find the file specified"
A.
Windows 2000/XP has a bug that it
cannot properly detect new hardware by *.inf files, if the RunOnce
registry key is missing from the following location:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
This key is often used by installers to execute post-reboot programs, but
sometimes they accidentally delete this key.
Go to Start » Run and enter "regedit."
Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
With CurrentVersion Highlighted, go to the Edit menu and select New » Key
Name the key RunOnce, leaving everything
else about the key alone.
The RunOnce key should now exist
underneath the CurrentVersion key. |