MMDVM Hotspot with ZUMspot Pi

So I’ve entered the relatively new digital modes (for me anyway) of DMR & YSF. This requires either a digital repeater or personal hotspot to access. The popular way to do this is with a software suite called MMDVM and currently there’s two Raspberry Pi images available that take care of having to build everything yourself. The first is PiStar and the other is by KB5RAB

I’m using the Pi-star image as it’s headless (meaning it doesn’t require a keyboard & monitor to run)and uses a webui to configure and uses a read-only file system once everything is loaded, whereas the KB5RAB is a full Raspbian desktop.  As you can see from the pictures I’m using a Raspberry Pi2 and the ZUMSpot Pi and a dual colour OLED.

When portable I have 10000 (mAh) 5v power pack that is about the same size as the case I’m using for the Pi2, so a few rubber bands double looped holds it all together rather nicely! The ZUMSpot Pi hat is the perfect size for fitting the OLED screen inside the case using some double sided foam tape stuck to the HDMI socket and the very top edge of OLED is resting on the CPU heat sink. Initially I was going to attach the I2C ribbon cable to the bottom of the Raspberry Pi, but if I ever want to swap the ZUMSpot out I’d be without the OLED so instead I attached it to the ZUMSpot hat.


Finally links to items…

Pi-Star by Andy Taylor

ZUMSpot Pi by Bruce Given

Generic OLED screen

Generic Nextion screen


Raspberry Pi SSTV

Here’s an article for using your Raspberry Pi as a SSTV transmitter! (similar to the Raspberry PiFM project)

As mentioned in the article above the source can be downloaded from GitHub

Meadowbank Fire activates Cambridge IMT

I got a phone call at around 17:45 to ask me what I had planned for the evening! I was just a little non committal at first, but after I phoned the contact from the IMT the picture was looking pretty grim so I put aside my reluctance and headed to Cambridge.


This is the site of the fire…


This is the temporary radio room…

The TFS details of this fire can be found at

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T2TAS First Birthday

Oh I overlooked T2TAS first birthday!

Back in December 2010 I applied to become part of the T2 server network. It’s now just a little over a year since then and for me I believe that it was a good decision to pursue. At the time of applying there was only two T2 servers located in Australia, they being T2AUST & T2SYDNEY. Now just a year on and there’s now 5. This has certainly improved the user experience within AU as this provides some more redundancy to the network.

Status pages can be viewed on…



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TinyTrak4 & Bluetooth

I was recently contacted by Byon (the developer of the TinyTrak) asking me if I was a user of APRSdroid. As I have an Android phone (HTC Desire A8183) I certainly do use APRSdroid! so I was asked to test out a serial bluetooth device for use with the TinyTrak4.

Here’s an image is of the TT4BT (the name as appears via Bluetooth) The unit draws power from the TinyTrak4 including voltage pass through so you can supply power for your GPS. For my testing I’m using the Byonics GPS2, the Bluetooth adapter is using the HC-05 module, I’m not going to cover the specifics of this module, but to say that Byon has set it for a serial speed of 19200 baud (factory default is 9600 baud) You won’t be needing to make any adjustments to this module!

The setup within APRSdroid is fairly straight forward, The only thing I altered was the channel number used from no entry (auto detect) to channel 1 although because of only having the one device this wasn’t essential. Included below is a rough pictorial guide on how to set up APRSdroid with Bluetooth.

The settings required for your TinyTrak4 (using firmware 0.67) is to simply set AMODE to KISS and ABAUD to 19200 baud. As you will be using APRSdroid to generate your position you’re not required to have a GPS connected to your TinyTrak4 (as APRSdroid is using your phones internal one!)

You can contact the author of APRSdroid via GitHub or on the IRC channel #aprsdroid on the FreeNode network.

Further details on the TinyTrak4 you can contact Byon on the following link

 I’ve purposely kept this brief as there are other resources that cover the specifics of these two devices from their respective developers, I didn’t see the need to recreate their content! 😉