AURSINC MMDVM Duplex Hotspot Module Dual Hat V1.5.2 with 0.96 OLED Display Support P25 DMR YSF NXDN DMR Slot 1 + Slot 2 for R Pi 1, 2/2b, 3/3b/3b+, 4/4b, Pi Zero, Zero 2W with USB Port (with OLED)

I saw some bad reviews on here so I wanted to say it's working great for me in duplex mode after upgrading the firmware. I'm using it with a Raspberry Pi 3B+. I was able to get the firmware upgraded using "pistar-modemupgrade hs_dual_hat" on PiStar after soldering the JP1 pads together and it upgraded to the latest firmware no issues.

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!

These boards are locked with v1.3.3 so you will not be able to use the newer digital radio options that are available. I have 3 other nodes running different MMDVM boards that are on 1.6.1 and 1.5.2 and work perfectly! I tried the customer support suggestions and now the board does not even work and the Raspberry Pi will not even make contact with the board any longer. I have tried it on different Pi versions as well as the primary hosts of Pi-Star and WSPD. The WSPD website even posted a request on their site asking vendors and manufacturers to NOT lock the boards so they could be updated when needed.

I purchased this to get into DMR. It matched nicely with my pi-star 4 which I also purchased on Amazon.The issues I have are that using the WPSD software, I could not get the firmware to upgrade. After numerous attempts and research, it was determined that you need to bridge the pads JP1. This pad is located on the bottom left corner. After doing a little soldering, I was able to get it to update to 1.6.1.No where in the instructions is this mentioned. Speaking of instructions...not so good. Good thing us HAMs are a crafty bunch. After lots of research I was able to get a few contacts in the log.The other issue I have is that I'am unsure whether the duplex portion of the board actually is working.To solve that I just switched everything to simplex. Problem solved.In retrospect, I probably should have purchased a simplex board.

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.

The Hotspot Module works as expected and advertised. The parts needed to fit it in various cases are included. Soldering the headers for use on a Raspberry Pi are covered in the instructions. Beyond that you will need to research how to configure it based on your end purpose.I paired mine with a Raspberry Pi 3B+ and a Nextion 3.5" screen in a custom plexiglass case. Any issues I had were due to configuring the software and are independent of the hardware.

So I have spent countless hours trying to get this to work on WPSD or the Pi-Star and tried multiple various combinations within the software. It will simply NOT work in duplex. It works very well in simplex so just be aware. I have also upgraded to 1.6 firmware and still had the same result. With that said, just be forewarned. I have also tried it with the Nextion and works very well in that regard. Just make sure you are on simplex.

I bought this because it is partially assembled. I'm glad I did.