AllStarLink :: RFless Node Mk I

I've wanted to build a radio-less node because sometimes it's easier and makes more sense than a radio-based node. Also, sometimes iaxRpt is a pain (e.g. fails to register with Asterisk, network latency issues, etc). But I wanted to make it look as much like a radio as possible.

This build is a bit more complicated than the super awesome and super simple MPow-071 Headphone hack. I love that hack and want to build a "radio" based on that at some point. This project is not that... because I wanted to manipulate Asterisk is direct and different ways.

Fob modification is for fools. Most importantly I wanted to avoid modifying the sound fob because the Pi has GPIO pins for a good reason: they are to be used. If you want to solder small wires to small chips on the fob, have at it. I still think it's a needless and clumsy workaround.

The radio carcass

I picked up this "for parts only" Motorola radio on Ebay for cheap. I was hoping there would be enough room to shoehorn the Pi and needed extra hardware and wiring. I lucked out! I was able to remove all of the radio's boards and that left all of the inside space for installing hardware.

(images of gutted radio)

Parts is parts

With the radio gutted, we could start installing the needed boards for the system:

• RaspberryPi 3A+ -- most favorite Pi board aside from the PiZero. Does the job of the 3B+ without the latter's crappy power management issues and with only the single USB port needed.
  
  
• Syba Sound fob CM119 chipset UNMODIFIED -- plug this into the Pi running HamVoIP and audio is piped out by default. That's a great sign. Is audio in on by default?? Amazon Link (2021-09)
• Microphone -- for that talkie talkie. Pick one you love. It will probably need modification.
• Audio amplifier board -- the Pi Audio out will not drive the radio's built-in 4ohm speaker. You could replace the oval speaker in the faceplate. But it seems better to drive the audio into a louder amplified speaker for noisy environments.

Hardware Assembly

Software Assembly

1. Configure rpt.conf events stanza

   stuff

   ; EVENTS ; replace with your node number, obvs [events514262] ; Commands for FOB COS indicator when available ; For this to work you must also add - gpio4 = out,0 - to simpleusb.conf ; Uncomment (remove ;) on next two lines to activate ;cop,62,GPIO4:1 = c|t|RPT_RXKEYED ;cop,62,GPIO4:0 = c|f|RPT_RXKEYED ; these will operate a front-face light to show radio is receiving voice from internet /var/local/sbin/gpio-4-high = s|t|RPT_TXKEYED /var/local/sbin/gpio-4-low = s|f|RPT_TXKEYED ; these will write the tranmit status of your node to a temporary file so that the PTT ; script knows whether to dis/engage the PTT/COS correctly ; write 1 to temp file = s|t|RPT_TXKEYED ; write 0 to temp file = s|f|RPT_TXKEYED ; these will operate a front-face light to show radio is transmitting your voice into internet /var/local/sbin/gpio-5-high = s|t|RPT_RXKEYED /var/local/sbin/gpio-5-low = s|f|RPT_RXKEYED
2. OPTIONAL Modify Supermon... for fun

   This quick modification to Supermon's link.php file allows you to PTT from the Supermon web page.

   // BEGIN KB9IQX print "

   "; if(isset($_POST['ptt_down'])) { echo "

   TRANSMITTING

   "; shell_exec("sudo asterisk -rx 'susb tune menu-support K'"); } else { echo "

   READY

   "; shell_exec("sudo asterisk -rx 'susb tune menu-support k'"); } // END KB9IQX
3. Install script for handling Mic Control

   stuff

References

• ref1
• ref2