Help: Getting PTT to tx with Digirig and ASL

As the title suggests, i am trying to get ASL up and running on a dedicated machine, but i cannot get simpleusb to tx. I saw an earlier post saying this was technically possible so i went for it. Digirig runs on RTS for PTT with a virtual serial port (Both serial port and the USB input are showing up in dmesg and lsusb respectivly). Cant seem to find any other info on this on the fourm. Also not hearing anything when using the simpleusb config menu to test the rx levels.

Any feedback is appreciated.

Hi have you put in all the information in your confi files?

To set up the tx you will have to put a line in the usb configuration file

Also you may be better running the Simple USB set up wizard to get the node to talk in putty ssh amd go to usb tune menu im hope im telling you right my friend as im newbi snd im trying to find out how to do it my self to be honest with you

Could you give some more details…
Pi or PC ?

Installed asl 1.01 or the 2.0beta6 or something else.

Most likely you are expecting cos and ptt to come from serial port (as in rs-232) and this is not the case for our input/output. Forgive me if I’m reading you wrong.

This is the most common way folks are doing it, unless you have a pc and can use a parallel port.
This works for all and most popular since it’s cheap.

setup software channel drivers

@Mike Some more details. Dedicated PC with asl 1.01. The way the digirig works is by sending an RTS signal over the serial port (CP2102 chip) which triggers PTT, and then sending audio out of the usb output, to the cm108 on the board, and then to the audio in to the HT. it seems that both are detected and working as per the screenshot below but i cannot get simpleusb to play nicely with it, or even get any audio in. drivers have been installed. I mean worst case senario i guess i could use it with vox if the PTT trigger wont work, but the audio in shouldnt have been a problem? Still new to this so i hope you can understand my confusion here.

@M6RWW.John as far as i know, yes i have configured it properly, but when doing the flash test in the simpleusb menu im not getting any audio in/out.

I’m sorry, I can’t concern myself to much with fldigi itself.
What are you using for inputs to the asl server ? cos / ptt

So we can try to match that with what you have in output from fldigi in some way.
or are both softwares in the same box ?

I can say that a common error is not having the correct description of the simpleUSB

rxchannel = SimpleUSB/usb_29285

and in simpleusb.conf

I will wait for additional.

ASL asserts a logic change on GPIO3 to create PTT. You may be able to assign code to make Serial commands work - but commonly PTT is derived from pin 13 on the C-Media chip. This pin (13) doesn’t connect to anything except a convenience pad in a Digirig - so you’ll need to do some work to complete the circuitry from that pin, possibly through some keying element (transistor), to the outside world (radio connector).

Additionally - you don’t have any receive audio - because, without further modification, there’s no way the DigiRig can tell the ASL application that the receiver is active. This is done minimally by connecting a logic low signal to the VOL DOWN pin (48) of the C-Media chip through a protection diode. A Schottky diode is commonly used (as opposed to a Silicon diode) to prevent an increase of voltage drop. In a Digirig, pin 48 doesn’t have anything connected to it except a convenience pad, so you’ll need to add this circuitry and connect it to the outside world (radio connector) to make it work. It’s ill-advised to not use a protection diode to protect the CM chip - here’s why:

The schematic is freely available for the Digirig and you can compare it to other “made for ASL radio interfaces” to evaluate and compare the differences. Digirig Mobile Rev 1.9 – digirig

For comparison - a list of ASL specific interfaces is available from the following page on my site:

While it’s certainly possible to connect and use a Digirig for ASL - it’s going to require some work.

Hope this helps…
Kevin W3KKC

Why not just run a second modified sound fob and define it as such ?