AIOC and SVXLINK

[F8ASB]

Hello all,

I'm trying AIOC with Svxlink repeater software,
AIOC is detected and audio level on alsamixer are available and /dev/hidraw0 is present on my Raspberry Pi.

For RX config is for a CM108 and SQUELCH(COS) detection on VOL_DW pin 48.
HID_DEVICE=/dev/hidraw0
HID_SQL_PIN=VOL_DN
SQL_DET=HIDRAW

For TX config:
PTT_TYPE=Hidraw
HID_DEVICE=/dev/hidraw0
HID_PTT_PIN=GPIO3

I have this error:
Wed Sep 11 10:04:09 2024: *** ERROR: unknown/unsupported sound chip detected...
Wed Sep 11 10:04:09 2024: *** ERROR: Squelch detector initialization failed for RX "Rx1"
Wed Sep 11 10:04:09 2024: *** ERROR: Could not initialize RX "Rx1"
Wed Sep 11 10:04:09 2024: *** ERROR: Could not initialize Logic object "SimplexLogic". Skipping...

Have you an idea to resolve this problem?

Maybe HID_SQL_PIN=VOL_DN isn't correct for AIOC.

[skuep]

Hi!
I am not familiar with the software. From what I can tell, I would guess that the last 3 errors are a result of the first error. And the first error is probably related to the fact that SVXLINK checks VID/PID of the given hidraw device, to detect what driver it needs to use (e.g. CM108). It doesn't recognize the AIOC's own VID/PID although the AIOC would be compatible to the CM108 chipset.

Currently, there are two ways to solve this particular problem. Either use the preview release and a python script to configure the AIOC for a different VID/PID. However this does currently not work on Windows.
#46

The second way is to use the firmware of G1LRO, that has baked these changes into the firmware.
#61
https://g1lro.uk/?p=676

In both cases, the VID/PID pair of the AIOC is changed so that it looks (almost) like a genuine CM108 chip to the computer. So it comes with all the caveats that you can read in those issues.

[F8ASB]

Hi!,

Thanks for your reply.

I'll try and report back on this thread.

[tomaz1]

Hi,

I have AIOC on SvxLink, and I can confirm the solution from G1LRO works.
I have also tried aioc-fw-1.3.0-rc.2.bin and setting the VID and PID to "Bus 001 Device 006: ID 0d8c:000c C-Media Electronics, Inc. Audio Adapter" with the Python script provided in the release notes: write(aioc, Register.USBID, (0x0d8c << 0) | (0x000c << 16)) also works!

Thanks @F8ASB for the settings provided:

Rx settings:
HID_DEVICE=/dev/hidraw0
HID_SQL_PIN=VOL_DN
SQL_DET=HIDRAW

Tx settings:
PTT_TYPE=Hidraw
HID_DEVICE=/dev/hidraw0
HID_PTT_PIN=GPIO3

It works, but with both solutions, when the station stops transmitting, I get Rx triggered after approximately 500ms, and the signal (silence) lasts around 300ms. (Rx is sending a short silence to SvxLink, and the AIOC green light is brighter, indicating it is receiving something.)

Why is Rx getting triggered (immediately) after Tx?

My current, not-so-good workaround/solution is to have two Rx settings and use "Voter" where I can set VOTING_DELAY=600.

P.S.: SvxLink runs in userspace as the user "svxlink", so it needed permissions to use /dev/hidraw0, like this:

cat /etc/udev/rules.d/99-hidraw.rules
KERNEL=="hidraw*", SUBSYSTEM=="hidraw", MODE="0660", GROUP="plugdev"
#Or if I would allow only (ID 0d8c:000c)
#KERNEL=="hidraw*", SUBSYSTEM=="hidraw", ATTRS{idVendor}=="0d8c", ATTRS{idProduct}=="000c", MODE="0660", GROUP="plugdev"

sudo usermod -aG plugdev svxlink

sudo udevadm control --reload-rules
sudo udevadm trigger

Edit:
I'm happy with aioc-fw-1.3.0-rc.2.bin and this settings on SvxLin (and ModuleFRN):

[Rx1]
...
AUDIO_DEV=alsa:plughw:2
AUDIO_CHANNEL=0
HID_DEVICE=/dev/hidraw0
HID_SQL_PIN=VOL_DN
SQL_DET=HIDRAW
SQL_START_DELAY=500
SQL_HANGTIME=1500
SQL_DELAY=1500

[Tx1]
...
PTT_TYPE=SerialPin
PTT_PORT=/dev/ttyACM0
PTT_PIN=DTR!RTS
TIMEOUT=240
TX_DELAY=100

[skuep]

I suspect you are using the VCOS for detecting incoming audio correct? From what I have heard about VCOS it tends to have issues with spurious activations. In current versions it will be possible to hardware a pin on the AIOC (e.g. unused PTT2) as input so you can tap a COS signal off the radio and connect it with the AIOC for this purpose.

For now I am closing this issue, but I thank you for sharing your experiences