Hi Sam,
Nice job. I especially like your keypad. How did you go about making that up?
Joe
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Hi Sam,
Nice job. I especially like your keypad. How did you go about making that up?
Joe
how much to cut me one of those boards and point me to the correct parts list. including display
Thank You
archie =) =) =)
P.S. I have an older circuit card that I cannot see well enough to drill and other issues lol
keyboard is from ebay, just put labels under caps.
1x White Keyboard 4x4 keys 16 keys Metal Panel, combined type keyboard | eBay
Display is also from ebay.
HD44780 2004 20x4 White Characters LCD Display Module | eBay
I just made the board on my cnc mill, I just do it as a hobby sorry. You can see if someone else can make the board for you.
Sam
Hi Archie,
I can't cut a board for you (I do have a spare but am in the UK) but the correct parts list with display details are in the file attached to the first post on this thread (by Kwackers - aka Steve) I found that Lucas' design (page 29 post No 346) is easy to produce using the toner transfer method for pcb'
Best regards,
Terry
Hi Sam,
I've now obtained the keypad type you used and I certainly like the tactile feel and the ease with which I'll be able to apply lettering — see pics below:
http://i923.photobucket.com/albums/a...ib/Keypad1.jpg
http://i923.photobucket.com/albums/a...ib/Keypad2.jpg
One thing surprised me though — the keypad is simply a 4 x 4 array of switches with no circuitry or wiring between the contacts. Can you explain how you handled this please — did you make a PCB or a matrix of wiring?
Joe
Hi Joe, did you figure out how to wire your keypad?
Hi Steve,
Only up to a point. In terms of literal hardwiring it's easy enough — two sets of 4 wires arranged at right angles, one set being being soldered to the 'row' pins, the other set to the 'column' pins, ensuring that the physical crossover points of the two sets of wires are insulated from one another. Then connect the tails from each set of wires to the control PCB as per the circuit diagram.
Ideally, though, I'd like to do this using a PCB. I've looked at some of the PCB layouts posted by other members who've made up keyboards based on loose key switches. Trouble is, the loose switches commonly incorporate active pins plus 'structural' pins, the latter not doing anything electrical but only providing additional support on the PCB. So, in looking at other peoples' PCBs I'm having trouble sorting out which solder pads are doing the active work and which are only along for the ride. In the case of my unit, of course, I only need 2 pads per key switch. Anyway, I'll soldier on or call out for help. If I work it out I'll post the solution.
Thanks
Joe
Hi Joe, I do apologise if the following is trying to 'teach granny to suck eggs' The 4 pin pcb tactile switches have two sets of pins connected internally as in the diagram here. A is connected to A1 internally and the same is the case with B and B1: -
http://i1044.photobucket.com/albums/...ps64091d9a.jpg
I have just edited this post and added a modified switch diagram which I pray shows the internal wiring of the switch and I hope helps to explain the concept of using it to produce a matrix keyboard, I do hope that i'm not insulting anyones intelligence :
http://i1044.photobucket.com/albums/...ps1a32a732.jpg
The internal connections create the horizontal rail in conjunction with the tracks on the pcb (below). An example is shown in red as if all the switches on that track were mounted. When the switch is pressed it connects the horizontal rail to the vertical through the A-B and A1-B1 connections. Hope this explains the pcb layouts published on this site.
http://i1044.photobucket.com/albums/...ps8493f804.jpg
Best regards
Terry
First of all let me thank Steve for great design. I also would like to thank everybody who posted to this topic.
My indexer does not start if crystal frequency is above 4 MHz. It just lit the first digit of LCD and freezes. At 4 MHz it works normally. PIC18F452, tested with 2.12 and 2.12c software.
What could be the reason for that?
Thanks!
Konstantin
Hi Konstantin,
check the layout around the crystal and associated caps - is there anything that could introduce extra capacitance? Make sure the joints are soldered properly for these components too.
Have you've tried different crystals? Have you tried replacing the two capacitors around the crystals? Finally a different 452?
Off the top of my head I would say it has to be one of those....
Cheers.
Steve.
Steve, yes I've tried with several crystals, the capacitors and connections also seems to be ok. Will try with another PIC. Can fuse bits settings be the reason?
Konstantin