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Forum Index : Microcontroller and PC projects : Ideas for Generic I/O Prototyping Board.
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donmck Guru  Joined: 09/06/2011 Location: AustraliaPosts: 1313 |
I should do this more often. I kick around ideas in a very small forum of colleagues, when I have a whole bunch of Maximiteers right here to give me feed back. The other edge of the sword is that design by committee can be very bloody difficult at times. But we will give it a go. After all, we are Maximiteers. Here is the current picture. We have an external prototyping board that has a female R/A header on the input end of things. I have sorted out what I feel is a simple signal I/O pin addressing system, but as it isn't finalized, I won't enlarge on this just yet. We then have provision for four LEDs and four switches. These can be isolated from the main bus. These are at the start of the board, near the input header. The first thing everyone wants to try with a micro, is to flash a LED, and read a switch. We have it set up so any LED or Switch, can be connected to any pin on the bus. By the same token, it can be fully isolated too. The board will be bare, and all "though hole" design, and not SMD, so that you buy a reasonably cheap board, and populate it from your junk box, or pick up a few parts from Jaycar or similar. It is what comes after the LEDs and switches which raises the questions. We could add a real breadboard, but this adds to the simplicity and cost of the design of the board. I guess at the very end of the board, we could have another 26 pin header that carries the bus signals through to another board. You could solder a straight, or R/A male into this. And carry that though to a breadboard for that matter. This is what Richard had to say: [code]Often the IO hardware will be some custom hardware setup by the user, eg some relays, and/ or some sensors. A generic prototyping board, with pin headers and space for transistors and relays and solder pads, I think this would be useful. [/code] Do we simply have strings of holes? What do users think? Cheers Don... https://www.dontronics.com |
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stuarts Senior Member  Joined: 15/06/2011 Location: AustraliaPosts: 199 |
I think I like the idea of strings of holes for the jumpers, you then have the option if soldering in pins and using plug on jumpers, or for a more permanent version, you could solder wirewrap wire for the jumpers. Or even use the wirewrap wire the way it was designed to be used by wrapping it around the pins. I feel that there should be a connector on the input and output side that allows daisy chaining of I/O boards. Stuart Time is nature's way of keeping everything from happening all at once. |
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| donmck Guru Joined: 09/06/2011 Location: AustraliaPosts: 1313 |
Thanks Stuart, I know exactly what you mean. Wire wrap? 
I did years of that. It's quick and neat, but I'll bet I can't find my gear in a hurry. You would know the semi-trailers we had the the DEC PDP 11/40s and 11/34's in. A lot of the back planes and gear was wire wrapped, and we drove it everywhere without any real problems. Not too many computers of that size, that were in the back of a big Mack. The USAF was interested in how we did it, as they wanted to fly the same computers. Don't know why I pulled that face, it was good actually, but for people not familiar, I think plug on jumpers, or solder. But if you solder, you can't easily re-use the pin for say a header pin, or header cable later, unless you really clean it up. But plenty of options. Cheers Don... https://www.dontronics.com |
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| stuarts Senior Member Joined: 15/06/2011 Location: AustraliaPosts: 199 |
I still find wirewrap wire great for soldered links Time is nature's way of keeping everything from happening all at once. |
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| Gadget Regular Member  Joined: 22/06/2011 Location: AustraliaPosts: 70 |
Me too |
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| donmck Guru Joined: 09/06/2011 Location: AustraliaPosts: 1313 |
I haven't done a wire wrap for 20 years, but I did enjoy it, and with the age group we are talking about in the Maximite forum, best I put wire wrap on the list of options in the way to configure the I/O selects. We have 3 methods then. 1) Solder (Soder for Capn't Bill and his two US buddies) 2) Wire wrap. 3) Little .025" jumper or header cables, 50mm for what we need. Cheers Don... https://www.dontronics.com |
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VK6MRG Guru Joined: 08/06/2011 Location: AustraliaPosts: 347 |
I think the plug on jumpers on header pins is the go for a prototype board, as it is a prototype board after all and should be designed for reuse. Also, the Maximite is a platform for beginners to have a play with as well as those with decades of experience. So something simple to modify as well as cost effective is the best bet. 
Its easier to ask forgiveness than to seek permission! ............VK6MRG.............VK3MGR............ |
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| donmck Guru Joined: 09/06/2011 Location: AustraliaPosts: 1313 |
Thanks I am about to post a new message on this issue of board addressing, so I'll start a new thread, as I want it as a new heading. Cheers Don... https://www.dontronics.com |
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| stuarts Senior Member Joined: 15/06/2011 Location: AustraliaPosts: 199 |
Don, do you ever sleep. I cant find a time of day that you dont post messages.... Time is nature's way of keeping everything from happening all at once. |
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| donmck Guru Joined: 09/06/2011 Location: AustraliaPosts: 1313 |
I did that once, and found it overrated Stuart. 
Re the board addressing thing, I posted the details in a new thread, and the item in full at: http://www.themaximitecomputer.com/maximite-io-board-address ing-for-bus-cable-interfacing/ And am eagerly awaiting feed back. Drawing is rubbish, but I hope the principle isn't. Cheers Don... https://www.dontronics.com |
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| Dave Everett Regular Member Joined: 24/06/2011 Location: AustraliaPosts: 43 |
While I haven't written a single line of code on my Maximite yet, the ability to 'compile' basic programs could be useful, it would speed up their execution once debugged. Dave |
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sparkey Senior Member Joined: 15/06/2011 Location: AustraliaPosts: 819 |
put me down for one of those boards don regards sparkey..thank you//please technicians do it with least resistance |
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| Ray B Senior Member Joined: 16/02/2007 Location: AustraliaPosts: 219 |
Don I think it would be essential to have a LCD Display Header using the same data lines as on Geoff's original LCD connection example. Maintaining consistance is important. With 6 lines for an LCD (when plugged in) this still gives a lot left over for general I/O ports. Cheers RayB from Perth WA |
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| donmck Guru Joined: 09/06/2011 Location: AustraliaPosts: 1313 |
Sure it does Ray, but as virtually any pin can be changed in BASIC code, it isn't a big job to use other pins. I am heading in the direction of the Arduino Shields. Google "arduino shield lcd" first hit: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1206025987 I didn't even look at the specs, but I know you can buy this sort of stuff on ebay for $16 inc postage. My DonDuino Cross will handle this sort of thing: http://www.themaximitecomputer.com/the-donduino-cross/ It can also be fitted to the new EV board.
Cheers Don... https://www.dontronics.com |
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