{"id":257,"date":"2026-05-26T06:28:43","date_gmt":"2026-05-26T10:28:43","guid":{"rendered":"https:\/\/www.thezoo2.com\/?p=257"},"modified":"2026-05-30T00:49:19","modified_gmt":"2026-05-30T04:49:19","slug":"the-pi-star-stack","status":"publish","type":"post","link":"https:\/\/www.thezoo2.com\/?p=257","title":{"rendered":"The ‘Pi-Star’ Stack"},"content":{"rendered":"
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Starting out with Pi-Star is a fairly common task these days, but in the early days of Pi-Star and DMR radio, we had to figure some things out the hard way, and on our own. I hope that this task is made simpler for you by posting this in our educational series.<\/p>\n\n\n\n

Basically, for DMR to work, there must be a repeater built that will allow us to put the digital mode into the repeater, have the repeater receive that mode, and then transfer it via both RF and the internet to connected repeaters around the world. Building repeaters used to be highly expensive and prohibitive until the advent of the MMDVM board, paired with a Raspberry Pi. <\/p>\n\n\n\n

Early on, a Raspberry Pi Zero was used with a small ‘hat’ that made up the MMDVM board. In those days, the MMDVM board was SIMPLEX in nature, and could only receive or broadcast at a given time. As developments came, the duplex MMDVM boards became available, and at the time of this writing, they are on version 1.5 or so, meaning there have been quite a few revisions bringing us more and more capabilities in the smaller boards. <\/p>\n\n\n\n

With the advent of the MMDVM board, we no longer need a repeater, as the MMDVM board is<\/strong> the repeater, handling receiving, broadcasting, and internet communications via the Raspberry Pi computer. <\/p>\n\n\n\n

Currently, we at The Zoo 2 are using variants amongst us of the same types of setups, but with different operating systems, but have basically the same hardware. This setup stack is as follows: <\/p>\n\n\n\n