A 3D Case for the TNC-Pi

TNC-Pi Printed Enclosure
TNC-Pi Printed Enclosure

In my last post, one of the things I mentioned was that I built a TNC-Pi shield for my Raspberry Pi, that allows be take part in packet radio. One of the things I didn’t like so much was that I had nothing to put it in to protect the circuits from dust or a misplaced screwdriver shorting out the board.

I was therefore pretty happy to receive as a birthday gift a 3D Printed enclosure designed to hold the Raspberry Pi and TNC from Scott VK7LXX. I’d pointed out the design about a week earlier when looking around, but lacked access to a 3D printer and spare time needed to print.

As you can see in the image to the left and above, it makes quite a comfortable fit. I used a bit of foam to sandwich between the Pi-TNC and the USB ports of the Pi just to prevent any contact of soldered joints with the metal casing around the USB connectors.

Scott tells me this printing was done at a “coarse” level, to speed up the print process and took around 3 hours to print. Those who are eagle eyed will notice that cases bottom is slightly rounded due to an imperfection in the print process – I’m not worried by this because the objective is to protect whats inside, not necessarily be pretty.

3-6 months ago, I was mocking the idea of needing a 3D printer, but I’m not laughing now. I can definitely see myself using a 3D printer to make custom parts in the shack!

Rig Control with RUMlogNG

My workspace for my radio gear is pretty limited, therefore space is at a premium. The Toshiba Tecra M2 which I used as my station computer for many years finally reached the end of its life, with none of the major operating systems supporting non-PAE chipsets. Not ready to purchase a laptop just for radio operations, I was hoping that I could use a more contemporary platform for operations Рan iPad.

A quick search around and I came across RUMlogNG, which is easily the best logging interface I have seen in a ham radio iPad app that is modestly priced.

RUMlogNG Logging Page

One of the more interesting features was that basic interaction with your radio was possible (reading of frequency, mode), with the suggestion to use one of Pignology’s Piglets. Reading the specifications of the piglet, it became apparent that what it was doing was taking the serial CAT interface of the rig control, and making it accessible over wifi network to connected devices by streaming the serial data out of a TCP port.

Armed with this information, went looking for alternative ways to connect serial interfaces to RUMlog, and happened across this forum post, talking about an app called remserial. After attaching a Serial to USB Converter to a Raspberry Pi, I was able to run the below command as root:

pi@raspberrypi ~/remserial-1.4 $ ./remserial  -p 7373 -s "9600 raw" /dev/ttyUSB0

The app did not crash when I tried this, so I assumed it was running, and then configured RUMlogNG to connect to the Raspberry Pi on port 7373. Success! RUMlog did not throw any errors and back on the logging screen, I saw that frequency and mode was being updated off the radio.

Rig Control with RUMlog