Re: Retrofit CAT on older QCX (serial #675) #cat

Hans Summers

Hi Bernie

Looking thru the latest QCX manual, I can not seem to find docs on the CAT pins.  What pins are RX and TX on?
Probably in the manual? Nothing on the schematic.  

Apologies for the confusion, this is in the manual but NOT the current PCB Rev 5 manual. To see the details of how to connect CAT to an older QCX see the Rev 4 manual.
And search for "CAT control"... I forget what page it is on. 

I will take this manual information and put it in a section on the main QCX page so that it is easy to find... 

I assume these are TTL levels and a RS-232 to TTL converter will do the job.

Yes they are TTL levels. RS232 levels won't work.

I just flashed the firmware to 1.05.  Attached is a pic of my old QCX with a laser cut case that I made years ago.


By the way - a reminder to everyone: all QCX firmware versions are compatible with ALL QCX PCB revisions even the earliest PCB as of the August 2017 launch. 

But in this case where you want to create a CAT serial port, if your PCB is Rev 4 or earlier, you need to add two resistors and a diode. If your PCB is Rev 5 then these components are already included on the PCB. 

73 Hans G0UPL 

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