New to AllStar, Asterisk, and HAM in general but no stranger to technology. I’m designing a simplex node with a graphical, multi-touch interface and digging in deep under the hood.
My setup is as follows:
Raspberry Pi 4 w/ ASL 2.0 Beta image
PIRIM radio interface Hat for RPi w/ SA818 VHF transceiver module
DFRobot 5" multi-touch TFT display (800x480)
The node is successfully transmitting received voice and telemetry tones over the air to my HT but but I am having a bit of an issue with received audio when the COS line is active (COS comes from the SA818’s Audio ON pin; according to the datasheet it is active low and it is connected to the VOL DN pin on the CM108B). It seems no matter how I configure simpleusb.conf, I cannot get both audio and keying to work simultaneously.
In order to get COS to function properly, I have to change the carrier source in simpleusb.conf from the default of USBINVERT to USB. However, doing this prevents any audio from being detected by ASL in simple-usb-tune menu option #2. I’ve confirmed the same with a fellow HAM who also has an AllStarNode. He sees me keying his node but cannot hear my audio.
The opposite is also true: If I change the carrier source back to USBINVERT, ASL is able to receive audio from the CM108B, but the carrier is not detected (the COS LED on the PIRIM module does not light up) so nothing is transmitted to connected nodes.
It’s almost as if the MIC IN on the CM108B is being pulled down (grounded) when COS is active. I’m 100% sure the CM108B device is properly capturing audio when COS is not active because I killed asterisk and did a test recording on the Pi using ALSA’s arecord utility. I used the command arecord -f S16_LE -D hw:2,0,0 and was able to capture my voice when talking into my HT.
Well, that’s the extent of the issue. I’m heavily invested in this project time-wise, money-wise, and emotionally so any help troubleshooting would be greatly appreciated!
Looks very cool. Please note however I am just starting to get my first ASL node on line. Having issues and have a lot more to watch on YouTube or read other places. James KD8AJC
On the surface James, I would say your cos logic is inverted.
Or active low is switching to ‘ground’ not 0v (you can test for that)
Not familiar with the module but if it is gating audio,
You might try a transistor buffer and convert it to active high.
That is just some guessing around.
False alarm. The active LED I was seeing on the PIRIM board was actually the PTT LED, not the COS LED! Immediately after this discovery everything made perfect sense. The node was activating PTT upon receiving audio from my HT and thus blocking any received audio as the SA818 is a simplex transceiver and can’t transmit and receive at the same time.
This was a cause for another concern and begged the question of why my node was in repeater mode. I was certain I set the duplex parameter in rpt.conf to ‘1’. I changed it to ‘3’ just to see what would happen and restarted the node. No dice. I changed it back to ‘1’ and again restarted the node. Voila. Everything worked. Doesn’t make sense but I’ll take it!
Now, if only I could convince those AllStar sorcerers to conjure up the app_jack module in the next release.
Currently there is no way to get the RX and TX audio stream since the simpleusb channel driver hogs the CM108B. This is a huge limitation in my opinion. It would be nice if simpleusb at least allowed specifying an alternate TX and RX audio device so I could create a dmix and dsnoop device in ALSA that would allow sharing the stream with other applications. This would allow me to do all kinds of neat processing on the audio and make better, less laggy visual elements like VU meters and such. As you can see from the video, using outstreamcommand to pipe the audio is super laggy.
