Metal case for duplex hotspot

posted in: DMR, Ham radio | 2

Unlike the “Jumbospot” most duplex MMDVM hotspots are not sold in a case.  You simply get the “modem” board and normally need to buy a Raspberry Pi and case separately.   I’ve tried making my own case from laser cut perspex, but it ended up being quite bulky, and I prefer to put RF devices into metal boxes, so I started to look for a suitable case which could be modified and eventually found … Read More

Non-invasive GD-77 debugger connections

posted in: DMR, Ham radio | 3

I wanted to connect a hardware debugger into another of my Radioddity GD-77s, but didn’t want to drill a hole in the side like I did on one of the radios…   But I then realised that the rubber protector that goes over the 2 jack sockets in the side of the radio, can be removed, and this gives a handy hole, through which I can feed the Serial Wire Debug wires.   Inside … Read More


posted in: Development, DMR | 17

m22_ghidra_psoec gd_77_ramdumpI suspect a lot of you are thinking, what on earth is Ghidra Well, that was my thought 2 days ago, when I was informed by Kai, DG4KLU that a open source reverse engineering tool, developed by the NSA had just been released to the public. For more details visit   This is great news in relation with reverse engineering the GD-77 firmware, because Ghidra has a lot of the features, previously … Read More

MMDVM hotspot – hardware network switch

posted in: DMR, Ham radio | 30

Several months ago, John VK4JWT asked me if I knew of a way to switch his JumbSpot between Brandmeister and DMR Marc using some sort of physical switch. John was interested in this feature, because he does a lot of mobile operation and it would be much easier to be able to flick a switch on the hotspot, when driving along in he car, than it would be to mess around with different channels … Read More