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

Ghidra

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 https://ghidra-sre.org/   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