Behind the scenes, work continues

So life gets in the way a little, thats normal. So goes it when you are working on projects. For me it seems I get started, then have to put it away for a while, and come back, such is the life story of the Repeater Controller.

So I had the prototype working, and it was ok, the boards I designed worked, but there is always room for improvement. I petitioned the University I work for to start a Maker/Radio Club, and asked if the repeater could be located on campus. Initial indications were that it was going to move forward. They asked me questions about the installation, my network needs, and initially rejected my request for space on the old club tower. I replied with a new location on the same building, and told them I would reduce power, and monitor for interference. If any occurred, I was already prepared to deal with it. All indications were they committee was happy, and then the President retired, a new one was sought out, hired, and everything fell through. Its been 5 months now and I havent heard anything from the committee. Im thinking, my request has been scraped. Its ok, Ill move forward, I still have a couple of options, back in the town I live in, that havent been explored. The University location would have covered both cities with minimal power, and ease, but I will now have to look into other avenues to cover the area I want.

Old Board, New Clothes:

The old design hinged on the use of the main computers parallel port. While this worked I did discover that parallel ports are tricky, especially if you accidentally send it a wrong signal, or in my case cross a wire. On the old computer I was using, I did this while wiring up a header connector, hence I lost that input on the parallel port. Not really a huge thing, but got me to thinking. I was using alot, I mean a lot of header connectors. I decided since the committee, was dragging their feet, or just plan quit on me, it was time I addressed that problem. Hence the next generation of boards. What started as fixing just a connector problem, blossomed into a full blown rework.

New Main Board

Old Main Board

The old board had everything external to it. There was the radio interface board, and the computer interface and tons of just boards, and more boards. What I did was reduce the clutter, and take those boards and incorporate them into just one board, complete with its own controller, and computer interface. As you can see by the top  picture, at the top of the board,  there is a radio interface port. This takes the old radio card, and puts it on the main board, its just plug and play. I also dropped all the extra channels. There is a interface for the repeater itseld, and just one other radio, whether it be a control link, for split site operation, or just another remote base, but the two additional radio ports were dropped. If I am having trouble getting a site for just the repeater, Lord knows I am not going to get a site thats going to allow 2,3 or even 4 additional receiver/transmitters.

All of the radio headers are now reworked and use the DB9 connectors at the bottom. All of the signals are routed through here ( COS, PTT, even a 5Vdc and a Ground, should an external key signal be needed. This removed 4 multiple pin header connector from the original design. Power supplies were removed and added externally to this new design. I reused the old supplies from my car project, just ordering more boards, and parts thus saving a ton of space.

Also I switched computers I am using. The new design uses the BeagleBoneBlack Version C as the brains of the controller as opposed to a full blown PC board. This saved space, and allowed the use of USB for signalling which Ill discuss in another blog. By doing this I saved power, space and time. Also by using the BBB VerC, I was able to get rid of some of the signaling ICs, and allow the computer more control, instead of having the computer tell the Arduino what to do. I still use the arduino to control some functions, which Ill get to later, but the use of the BBB really streamlined things! With all of this, cost was also reduced. Original boards for the old system were over 30 dollars for 3, making them a little over 10 bucks a piece, the new boards were just 15 dollars for 3 and cost 5 dollars per board, a 50% savings.....not big bucks, but hey I can buy more parts now.

Thats about it for the new main board design. Its working like a charm, and has added features as well which Ill outline in another blog as well. So work is continuing, and coming along nicely.

Happy Coding!