[chbot] USB - RS232 modules.

Andrew Errington erringtona at gmail.com
Sun May 13 02:03:22 BST 2012

On Sun, 13 May 2012 07:26:34 Chris Hellyar wrote:
> Hi-ho folks...
> Anyone got a pick for a logic level USB-RS232 module with a mini-USB
> connector built in for an embedded project?
> Heaps show up on Mr Google so wondering what has already been used to
> save me some pain. :-)
> For the curious; it's to use as the PTT interface for an echolink
> interface, just using RTS and the 5V for some LED's. ref:
> http://www.echolink.org  I'm currently using a USB-serial dongle and I
> want to tidy up the cable mess to make it a permanent install rather
> than a birds-nest.
> Cheers, Chris H.

Word on the street is FTDI is the one to choose.  I have bought some of the 
shot-moulded USB->RS232 adaptors and peeled the plastic off to access the TTL 
lines on the FTDI chip.  In my meanderings so far this is the most 
cost-effective way as the 'breakout boards' are far more expensive.

What are you using for your audio in Echolink?  I did some work to utilise a 
spare I/O on the audio chip in a popular USB audio dongle.  The I/O can be 
hooked up to PTT, which eliminates the serial port (or its equivalent) 
entirely.  Code is present in the latest 'soundmodem' and 'hamlib'.



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