AURSINC MMDVM Duplex Hotspot Module Dual Hat V1.3 Support P25 DMR YSF NXDN DMR Slot 1 + Slot 2 for Raspberry pi with USB Port (Without OLED)

If you arent familiar with hotspots or Pi-Star or Raspberry Pi in general, youre going to have to do some research. This does work on a Pi 4. The description was likely created before Pi-Star was updated to support Pi 4. Some complained of the screen not working - you have to configure that in Pi-Star. Some said it didnt work at all - you have to configure the correct modem type in Pi-Star (STM320DVM / MMDVM_HS - Raspberry Pi Hat GPIO - On the instructions). There are I believe 2 other types that will work but as suggested by the Pi-Star forums, use the one above. If you already have a Pi, this is one of the cheapest ways to get on Pi-Star. If you dont have a Pi and want a full blown case with large screen, its not much more to just buy a 250$ prebuilt and a lot less hassle if you arent familiar with any of this stuff. I have 0 issues with sound quality or BER from mine using either an FT5D or IC9700 on either Fusion or DStar. It runs perfectly fine wirelessly or even off of my cell phone hotspot in the truck. Dont worry about heat if using a Pi 4. It averages 138' or 127' with a Pimoroni Fan Shim which isnt necessary. The Pi will never over heat it throttles down first and wont even throttle down until it hits 176'. Pi4 is overkill - Pi3 is actually overkill to run one of these so dont think you need a Pi4 for best results even given the better WiFi performance, the Pi3 is more than adequate. I had a spare Pi4 so thats what I used. The instructions that came with it are minimal. To be honest, they provide exactly the information needed to setup Pi-Star with the modem and how to update the firmware of the modem. If you dont understand Pi, they will seem like they are useless. Not to be rude but thats what they are. If you are not familiar with any of it, you can set this up with no problems if you do a bit of research first into Pi-Star and MMDVMs in general. They are all about the same. Check out the Pi-Star forums for a lot of answers. If youre looking to DIY a hotspot (and you should because the mark up on most of the others is pretty ridiculous) this is a perfectly fine MMDVM board. One thing to mention is that you need a radio capable of DStar or Fusion or DMR etc to use this. This will not allow you to use an FM radio to transcode the digital modes. This will transcode from DMR to Fusion or Fusion to DMR as an example but will not do DStar to Fusion. I know of one hotspot in the 400$ range that will transcode DStar to Fusion. The RF power on this thing is also impressive. Default settings using 100% power, I was able to hear from about 200 yards away while the unit sat inside my house in the basement and I was in my truck. I have since turned it down to 10% power since it sits 3 feet from my radio(s). Bottom line - this works perfectly fine and works well if you are able to configure everything. If you get stuck, forums exist with answers to your questions already. 73

I was trying to find a well made MMDVM duplex board and I spent over a week doing research, the popular auction site had hundreds of them, some for half the price as this, but those boards looked cheaply made and did not specify any specifications or instructions. I wasn't going to waste my time waiting weeks for a board to arrive from China and up getting something that might not work. This board works quite well with a Pi 3 B+, which is what I recommend using since it has the horsepower to process everything. With that said, once you get to the point where you upgrade the firmware on this board, you can easily do so without soldering anything. Take an alligator/crocodile clip and file the teeth down on one side of the clip, making it flat, then for the other side of the clip, take some heat shrink tubing and slip it over and heat it up. Do this 2 or 3 times. (electrical tape should work too) Needless to say, you take the clip and clamp it on the board where the flash jumper traces are. This is much better than soldering. Boot it up, use SSH to issue the firmware upgrade commands, power down, remove the clip and then power it back on again. Done!

I received the MMDVM board today, The promised date was one day ago, I will rate 4 out of 5 stars. Minus .5 star for missing a the promised delivery date. And another .5 star subtracted because this is more expensive by $20 to $30,00 than others that are similar. But the others were not in stock and delivery would be many weeks away. I guess if you have it when others don’t you charge what you want.I give 4 stars because the product works out of the box as expected. I have the latest version of Pistar running on the pi 3B and the MMDVM board. I can use it with DMR Brandmeister and DMR + networks and my Anytone 878UV +.Thanks for getting it here in good shape.

This hat just works. It works right out of the package. It works on a RPI 4B 8meg PIE. It even works without a firmware flash. comes with 1.4.7 and flash to 1.5.2. Did i mention that this is my second hat in one week and everything just works. SHY Store is the place to buy from on Amazon. They have treated me well and I will buy from them without worry. The temp in my RPI 4B is 38c/100f. That works for me.If i had known that these duplex MMDVM boards worked on RPI 4b with 8 meg I would have not purchased the 3b+ I have for the first one.And this MMDVM Duplex hat has connectors for Nextion screens and a few more ports.Both my MMDVM Duplex setups have been rock solid with Brandmister and TGIF, not one problem.Did i mention that it says it doesnt work with Raspberry pie 4B, but it does.If your board is hard to flash follow the picture. jumper-0=1 means just that. add a loop of solder into the holes of jumper 0.

This Duplex MMDVM Rf board is an earlier production date 06/2018. It must have been replaced by a correctly designed board dated 09/2018. I have 5 of those RF Duplex boards. All work as they should without issue. This board simply doesn't. It appears there was a design error that left off some connections going back to the Raspberry Pi computer that are used to send operating parameters of the duplex RF board to the computer. Without these connections providing necessary feedback to the computer operation is erratic at best and limits it's operation. It manifest the problem by the computer not being able to command the duplex RF board properly. Display feedback is missing or erroneously display if at all when using a large display screen. In testing I replace a known correctly working duplex RF board in two different units and had them both fail to operate as they should. I do not in any way recommend this item.