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Absolute Newbie needing help


Guest asciifish

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Guest asciifish

Ok, I'm an absolute newbie at electronics (not quite, I know basic parts, how to soldier, ohms law, etc) and for some bizzare reason, I've decided to try making my own MIDI keyboard. The schematics (http://www.geocities.com/JDPetkov/Hardware/midikeyb/midikeyb.htm) for this which I've found and like invovle a 16F84 PIC so I need to make a card to program the chip. I found the handy project for the card on this wonderful site and decided to go for it. This is probably not the wisest thing for me to do, but I've already invested in all the parts so I'm pretty much commited :-[. Anyway, I have three questions:

1)So far I've tried and failed twice to make a PCB for the programmer. Both attempts were with a sharpie and ferride chloride. I can't afford/find the supplies to the UV etching and I'm a little stumped on how to do it with my printer. Does anyone know of a method that uses an inkjet? Or failing that, I've seen a number of different ways to use an laserjet. Do overhead transparencies really work? TIME magazine sheets? Any other pointers on this subject?

2)I've noticed that a lot of the software seems to either have issues with XP and/or the parallel port. Does anyone know of a program that works with XP through the parallel port or any other solutions to communicate with the programmer?

3)Finally, and good general tips or pointers?

Thanks in advance!

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1)So far I've tried and failed twice to make a PCB for the programmer. Both attempts were with a sharpie and ferride chloride. I can't afford/find the supplies to the UV etching and I'm a little stumped on how to do it with my printer. Does anyone know of a method that uses an inkjet? Or failing that, I've seen a number of different ways to use an laserjet. Do overhead transparencies really work? TIME magazine sheets? Any other pointers on this subject?

I've done quite a few boards in a way that sounds similar to what you're trying. The Sharpie brand markers won't stand up to Ferric Chloride for an etching, but the markers I used usually do: Staedtler's "Lumocolor" series markers. I think they're supposed to be overhead transparency markers, but if you clean the copperclad with a good liquid cleaner, then draw your circuit traces/pads onto the copper with these markers, avoid getting fingerprints/dust/dirt/etc. on the board, and give the ink half an hour or so to be sure it's thoroughly dry, you can etch the board pretty well without any trouble with the etchant eating away at the copper under your traces or the ink actually coming off and etching off your traces. After etching, you can get the ink off your PCB with some very light use of 0000 steel wool.

As for upgrading to a computer generated, printed pattern, you can avoid most of the cost of the equipment by building your own exposure box (basically a wooden box with a 300W bulb at the bottom, with air circulation to vent heat), and using pre-sensitized positive exposure circuit boards. The box allows the light to shine through a glass plate, over your printed pattern, and hit the copperclad. The dark lines/circles in your pattern end up as traces/pads on the board. The glass, pattern, and copperclad are kept in place in a 'rack' which is supported inside the exposure box. There are plans for boxes on the Internet and in books related to making your own PCBs.

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Actually, if you use a "black Light" bulb, it will take less time and not generate the heat requiring a fan. The heat actually impedes the imaging process with the photo etch chemicals. My system uses 4 18" tubes and can produce a 12" x 12" board in a very short period of time.

If you only need a small light box, you can find the round bulb and use that. It will cut down your time, lessen the fire hazard, and give better photographic results.
Hope this tip is helpful.


MP

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In order to program the parallel port under Windows 2k/XP you will need a special driver because these operating systems do not provide direct access to the parallel port (as it was done by the OUT command in Win95/98/Me).

I have found this excellent component for Delphi, which I have tested and it works perfectly.

Another solution is the PortTalk driver (http://www.beyondlogic.org/porttalk/porttalk.htm)
if you prefer to program in C, but it is more complicated.

I can also give you the source code of a simple project I have made in Delphi that controls eight leds from the parallel port.
The schematic is trivial : pins Data0 to Data 7 connected to a ULN2803 darlington transistor array, then to current limiting resistors of 220-300 ohms and then to the positive leg of each led. Negative legs alltogether to ground.


ParallelPort.zip

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  • 1 year later...

this is the way it works for me, go down to the stationary store and buy some photocopier(ie laser) hp photo paper copy your design onto this remembering orientation of board(you might have to mirror the copy) make the copy as dark as possible once satisfied with the copy lay it ontop of the copper with the printed surface facing the copper. using your steam iron press firmly on the back of the photo paper ironing all around the circuit print once satisfied with this using hot water and a tooth brush wash the paper backing away carefully this will leave the copy on the copper ready for etching simple hey

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  • 2 weeks later...


Another solution is the PortTalk driver (http://www.beyondlogic.org/porttalk/porttalk.htm)
if you prefer to program in C, but it is more complicated.



If not done right the port talk program can repeatedly crash you system.

The program I use with my JDM (kit built cheap!!) is IC-prog. www.ic-prog.com

you dont need any prot access programs if you select the windows API option. Its a little slow but works.

This program also has an inbuilt program to use the prots but it can create "privilaged" errors. So I steer clear.

If you already have the parts and dont want to buy a whole kit, Often you can get just a PCB you will find many of the components needed are the same as what you already have.
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