I got a newer duplex board several months ago from the German group building them. It was supposed to be an update of the Bi7jta I got last year. I am not so sure it is much different other than it does have a different crystal but otherwise , so far, it works about the same for me. I am sure I need to give it a better test than monitoring several talk groups… ha!
My issues was that none of these come with big screens for old eye viewing. Most of them do not come with a decent case for the Raspberry Pi and or the MMDVM modem hat added to it. So I have been searching for adequate fixtures for making it a big more solid, presentable and able to stand on it’s own on the shelf. I have hit upon the following for my home based hotspot…
1. mount the raspberry pi in this case….https://www.amazon.com/gp/product/B073W5MQGB/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
This case puts a fan above the PI and below the mmdvm modem for cooling and so far it is working great… previously some of my boxes, cases, etc. would allow the Pi to run from 115 deg to 125 degrees but this one is running under 110 even under sustained radio use…
I also got a 7 inch Nextion enhanced screen several months ago and had it working for a long time but it did not have a frame, case or anything stable it was just held up by a frame and a back board on the screen… but I found this:https://www.ebay.com/itm/183607764452
It holds the screen on both sides, and by putting in a couple of spacers for the back plate… it will stand on it’s own…I had to do that anyway as the back plate of course was not exactly the same as the back of the nextion? but then… I used the bottom piece of the above pi case for a template and put holes in the back plate and mounted the pi case on the back of the screen to add weight, and make the stand a lot more solid as well…
I am using the USB to TTL here and need to get the right plug end for the nextion and shorten the cable a bunch so it all lays in much better but that is something I am working on.
Next I got some GPIO standoff pieces that raised the GPIO pins out so the MMDVM modem could be mounted outside the pi case, above the fan, and where if I want I can swap it out at any time with another version… but seeing that the modem was now outside the case and open to … mis-placed figures I cut a small pieces of acrylic to cover the modem, and protect it… added a few more standoffs and plastic spacers to keep it all solid and the back side now is:
Very stable on the shelf, solid, covered parts, boards , and adequate cooling…
I now need to write up an early project of putting to smaller units into a carry box with battery power… but that is something to work on …
WD0AJG
WD0AJG - Hamming for over 40 years 