Carl,
 
 
I have been using PP for PTT and COR, etc, works VERY well.
 
You need to have used source code, specifically app_rpt.c and chan_usbradio.c that is from after about Sept 14
 
Before that it didn't work.
 
I want to write up a cookbook process for what I did with it, just need time, like I want to put together a how to for Limey, as I had modified it, but time is a problem...
 
 
 
These are the devices that will work, you can find from running lsusb with the device plugged in:
C108_VENDOR_ID 0x0d8c
C108_PRODUCT_ID 0x000c
C108AH_PRODUCT_ID 0x013c
C119_PRODUCT_ID 0x0008
C119A_PRODUCT_ID 0x013a
 
Most common is the C108, which will display 0d8c:000c
 
In the usbradio.conf I use:
 
;
; Usbradio channel driver Configuration File
;
 
[general]
 
[usb]
 
hdwtype=0               ; Leave this set to 0 for USB sound fobs modified using
                        ; the instructions from usbfob.pdf. Use a setting of
                        ; 1 is for Dingotel/Sph interfaces.
 
rxboost=1               ; 0 = 20db attenuator inserted, 1= 20db attenuator removed
                        ; Set to 1 for additonal gain if using a low-level receiver output
 
rxctcssrelax=1          ; reduce talkoff from radios w/o CTCSS Tx HPF
                        ; Do not change this, leave this as a 1
 
txctcssdefault=114.8    ; default tx ctcss freq, any frequency permitted
rxctcssfreqs=114.8      ; rx ctcss freqs in floating point. must be in table
txctcssfreqs=114.8      ; tx ctcss freqs, any frequency permitted
rxctcssoverride=1       ; Set to 1 or yes to start out in carrier squelch mode
 
carrierfrom=ppinvert            ; no,usb,usbinvert,dsp,vox
                        ; no - no carrier detection at all
                        ; usb - from the COR line on the modified USB sound fob
                        ; usbinvert - from the inverted COR line on the modified USB sound fob
                        ; dsp - from RX noise using dsp techniques
                        ; vox - voice activated from RX audio
 
ctcssfrom=no            ; no,usb,dsp
                        ; no - CTCSS decoding, system will be carrier squelch
                        ; usb - CTCSS decoding using input from USB FOB
                        ; (currently not supported)
                        ; dsp - CTCSS decoding using RX audio in DSP.
                        ; rxdemod option must be set to flat for this to work.
 
rxdemod=speaker            ; input type from radio: no,speaker,flat
                        ; no - RX audio input not used
                        ; flat - Use RX audio from discriminator (before de-emphasis)
                        ; speaker - use de-emphasized audio
 
txprelim=no             ; Audio processing on left output channel: no,yes
                        ; no - Audio is not pre-emphasized and limited.
                        ; Suitable for use on a microphone input
                        ; yes - Audio is pre-emphasized and limited.
                        ; Suitable for direct connection to an FM modulator
 
txlimonly=yes           ; Audio limiting with no pre-emphasis on output channel: no,yes
                        ; no - Audio is not limited.
                        ; yes - Audio is  limited.
                        ; Suitable for transmitters with no limiting but with pre-emphasis.
 
txtoctype=notone        ; Transmit tone control type: no,phase,notone
                        ; no - CTCSS tone encoding with no hang time
                        ; phase - encode CTCSS and reverse phase
                        ; AKA ("reverse burst") before unkeying TX
                        ; notone - encode CTCSS and stop sending tone before unkeying TX
                        ; AKA ("chicken burst")
 
txmixa=composite        ; Left channel output: no,voice,tone,composite,auxvoice
                        ; no - Do not output anything
                        ; voice - output voice only
                        ; tone - CTCSS tone only
                        ; composite - voice and tone
                        ; auxvoice - auxiliary voice output at headphone level for monitoring
 
txmixb=composite                ; Right channel output: no,voice,tone,composite, auxvoice
                        ; See txmixa above.
 
invertptt=0             ; Invert PTT 0 = ground to transmit, 1 = open to transmit
                        ; This is the collector lead of the 2n4401 on the modified
                        ; usb sound fob.
                        ; please refer to the howto for the procedure to do this.
pp2=ptt
pp11=cor
 
duplex=0                ; Full Duplex
 
rxondelay=2             ; Uncomment and/or adjust for simplex nodes to eliminate "Ping Ponging"
                        ; or "Relay Racing".
                        ; A positive value here will instruct the usbradio driver to ignore the
                        ; COR line for a specified number of 20mSec intervals following the
                        ; release of PTT. Use this only on simplex nodes, and leave commented
                        ; out for repeaters or other full duplex nodes.
 
 
 
 
 
 
 
 
----- Original Message -----
From: Carl Davies
To: app_rpt-users@ohnosec.org
Sent: Sunday, October 02, 2011 11:09 AM
Subject: [App_rpt-users] Serial/Parallel interface

Hi Andrew, thanks for the reply, yes the problem is Blobbed epoxy chips.
Even when the vendor shows the chip type or even picture, there is no guarantee it will not be a blob, I have fallen foul of cheap Chinese imports on Ebay.

I have since found the information relating to the parallel port here,
http://ohnosec.org/drupal/node/177

Thanks,
Regards
Carl M1ELR ALLLSTAR node 27473.



On Sun, 02 Oct 2011 22:09:18 Carl Davies wrote:
> Hi group,
>
> Carl M1ELR here, I noticed in a post a few days ago there was mention of
> using the Parallel port for PTT or COR, is this possible?
>
> I currently run my node using the Centos install package from the Allstar
> site but can change to the install version from Xipar if needed.
>
> I have without success been buying sound fobs to build a new interface and
> now have a drawer full of USB fobs that I can't mod, if the I/O wasn't via
> the USB sound fob that would make life so much easier as the CM108 seems to
> be getting harder to source.

Hello,

What is the problem with those USB fobs?  Is it that they are epoxy blobbed?

If they are packaged chips, is it because they are not CM108?  What chip are 
they?  Please post the vendor ID/Product ID info.  I have been working with 
CM108 compatible chips- maybe I can contribute something useful here.

73,

Andrew
ZL3AME