My homemade RF node has no receive! Help!

Hello! I am working on building a Allstar RF node using a Raspberry Pi 3B, a cm108 sound card, and a baofeng bf888s. I saw a few guides on how to build one so I got the parts and started working. I have it all set up and running but there is a problem.

When the BF888s gets the signal coming from my HT it doesn’t key up allstar. I can do *70 when connected to the node over DVSwitch and it will recite the node information over RF and I can hear that. So it’s activating TX on the 888s with no problems, but RX doesn’t work. I checked the COS wire so many times and it’s correctly connected, and it does go HIGH on RX like it’s supposed to. I changed carrierfrom = usbinvert to carrierfrom = usb but it had no effect.

I may have a defective cm108 sound card so I did order a new one that will be here soon. On the chance that that’s not the case, something else may be wrong. I used these two guides to build it: CM108 Sound Fob Modification and this: Baofeng BF888 Modification. If you need any more info I’m happy to give it, because I’m stumped right now. I checked everything so many times but I can’t find the issue. The wiring must be correct. All that’s left to do now is desolder all my connections and redo the whole thing from the start.

Could you test this live and running at your COS on the sound fob for voltage when active.
What is the voltage active?
Voltage inactive ?

From a command line,
you can watch the live verbose of asterisk,

asterisk -rvvv

Perhaps it is triggering so watch that output for a check and tell us if you see action in the software on cos true.

I was redoing everything from scratch and I accidentally destroyed 3 of the pins on the cm108 chip. I have a new one that I’ll be working on today. I think the COS line was putting out something like 2-3v when a signal was present.

Update: After getting a new CM108 sound fob and trying again, IT WORKS! I had to put an external antenna on the bf888s because when it keyed up (in response to me transmitting), it would keep itself in a loop of waiting 5 seconds, doing the curtesy tone, then waiting 5 secs and beeping again. My guess is having the TX antenna so close to the wiring was causing a voltage to appear. Switched to a better antenna and the problem is solved!