Linux PTT issue with Hardware PTT.

Custom Products for the Digital Radio Amateur Enthusiast

Linux PTT issues with Hardware PTT.

There are two help sections in this article.
Both deal with PTT assertion of Linux programs. The first deals with Direwolf and the second with ARDOPC.

HTML by Kevin W3KKC

Background:
I had a PTT problem when using the DRA-36 as a TX Only interface under Linux. The DRA-36 was assigned by Direwolf to take control of the PTT via GPIO 3. After the first frame was sent out ufb, the green LED stopped flashing and thereupon the blue LED went out - keeping the DRA from asserting the PTT. All following frames were sent out at different lengths in time - - varying sometimes even to almost zero.

A solution to which I stumbled across is just to let pavucontrol (PulseAudio Volume Control) running beside Direwolf. pavucontrol keeps the green LED flashing and thereupon the blue LED lit solidly and PTT works fine all the time.

The problem doesn't occur when using the DRA for both RX and TX.

73
Daniel, DL7NDR

The following comes from Ger Koper.

Dear Kevin.

I am trying to get Winlink going via my Raspberry Pi connected to the DRA. The first method I tried is using ardopc, see this document.

To add PTT control the device name needed is "/dev/hidraw0", so "-p /dev/hidraw0" is to be added to the command line.

But that is not all. Permission has to be given by adding the line
KERNEL=="hidraw*", SUBSYSTEM=="hidraw", MODE="0666"
to the file /etc/udev/rules.d/99-com.rules and restart.