AIOC

This is the Ham Radio All-in-one-Cable.

What does it do?

The AIOC is a small adapter with a USB-C connector that enumerates itself as a sound-card (e.g. for APRS purposes) and a virtual tty ("COM Port") for programming and asserting the PTT (Push-To-Talk).

Features

Digital mode interface (similar to digirig)
Programming Cable Function via virtual Serial Port
Compact form-factor (DIY molded enclosure TBD)
Based on easy-to-hack STM32F302 with internal ADC/DAC (Programmable via USB bootloader using DFU)
Tested with Wouxun UV-9D Mate and Baofeng UV-5R
Works with Direwolf (Notes on APRSdroid below)

Future Work

Enclosure (DIY using 3D-Printed mold and Resin)
Maybe integrate a TNC Modem with KISS interface? (I am not sure if that is worth the effort)
Maybe change the USB-C connector type due to sporadic connection issues with JLCPCB's SMT reflow process

How To Fab

Go to JLCPCB.com and upload the GERBER-k1-aioc.zip package (under kicad/k1-aioc/jlcpcb)
- Select PCB Thickness 1.2mm (that is what I recommend with the TRS connectors I used)
- You may want to select LeadFree HASL
- Select Silkscreen/Soldermask color to your liking
Check "PCB Assembly"
- PCBA Type "Economic"
- Assembly Side "Top Side"
- Tooling Holes "Added by Customer"
- Press Confirm
- Click "Add BOM File" and upload BOM-k1-aioc.csv
- Click "Add CPL File" and upload POS-k1-aioc.csv
- Press Next
- Look Through components, see if something is missing or problematic and press Next
- Check everything looks good and Save to Cart

How To Build

You need to use Monacor PG-204P and PG-203P or compatible TRS connectors (2 solder lugs and a big tab for the sleeve connection)
Cut the 2.5mm and 3.5mm TRS sleeve tab where the hole is located
Put both TRS connectors into the solder guide (or a cheap HT that you don't mind potentially damaging). Make sure, that they are seated all the way in
Solder sleeve tab on the back side for both TRS connectors first
Turn around PCB and solder remaining solder lugs

How To Program

Short outermost pins on the programming header. This will set the device into bootloader mode in the next step.
Connect USB-C cable to the AIOC PCB
Use a tool like dfu-util to program the Release Binary like this:
```
dfu-util -a 0 -s 0x08000000 -D aioc-fw.bin
```
Note that a libusb driver is required for this. On Windows there are additional steps required as shown here (DFuSe Utility and dfu-util). On other operating systems (e.g. Linux, MacOS), this just works ™ (provided libusb is installed on your system).
Remove short from first step, unplug and replug the device, it should now enumerate as the AIOC device

How To use with Direwolf for APRS

Follow the regular setup guide with direwolf to determine the correct audio device to use

Configure the device as follows

[...]
ADEVICE  plughw:<x>,0
ARATE 48000
[...]
PTT /dev/ttyACM0 RTS -DTR
[...]

How To use with CHIRP for programming

Start CHIRP
Select Radio->Download from Radio
Select the new COM/ttyACM port and start

Notes on APRSdroid

Although theoretically not an issue, currently APRSdroid is not supported due to the following two issues:

According to ge0rg/aprsdroid#156 the sample-rate is fixed to 22050 Hz. Currently, only 48000 Hz is supported by the AIOC (and 24000 Hz or 12000 Hz would be possible to implement). However it should be possible to also support 22050 Hz although with an approximate frequency error of 90ppm (which however should be fine for APRS)
Currently APRSdroid does not support any PTT control via a serial interface. See ge0rg/aprsdroid#324 However my previous experience is, that the Android kernel brings support for ttyACM devices (which is perfect) so implementing this feature should be no problem.

nanderoo / AIOC