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Topic: Perfboard for a noob. (Read 7522 times) previous topic - next topic

Panici

Dec 30, 2011, 05:14 am Last Edit: Dec 30, 2011, 05:16 am by Panici Reason: 1
Hello Everyone,
I've just written this post, but my session timed out and I lost it.   :0
Here we go again..

Anyways, I'm wiring up this circuit, with 2 shift registers (I may expand upto 5) and 4 displays (may expand upto 9).



I need 8 common buses for the 7 display segments, and the decimal point. These will go to all of the displays.
I also need 2 common buses for Shift Clock and Latch Clock, which will go to all of the shift registers.

There's 4 Common Cathodes per display, that go to the shift registers.


I've got a sheet of blank perfboard, and a sheet with individual solder pads.
What's the best way to make buses on perfboard? Also, any tips laying this circuit out before I start soldering?

I've also got IC sockets for the shift registers and headers for the displays, so I don't burn anything out with my noobie soldering skills.

Thanks in advanced!
Electrical Engineering Student

CrossRoads

Download the software from expresspb.com, really easy to use the pcb software to layout the chips and play with placement.

Bunch of "island of holes" boards here, copy the dimensions into expresspcb and start working the layout.
http://www.futurlec.com/ProtoBoards.shtml#PRBRDLG

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

CrossRoads

I find wirewrapping digital circuits with lots of connections is a great way to go as well. Line up the parts with shared connections, and just go pin to pin to pin, highlighting them on a paper schematic as you go.

Socket pins like these for each chip
http://www.king-cart.com/cgi-bin/cart.cgi?store=phoenixent&product_name=HWS15765

and an Oki Industries wirewrap tool
My tool of choice is the WSU-30 & 30 guage wirewrap wire.
http://www.jonard.com/jonard-ecommerce/control/product/~category_id=HAND_WRAP_TOOLS_1/~product_id=10021
but others have had okay experience with the Radio Shack version as well. I find it clunky myself.

Once you have a layout you like, solder the end pins down on a socket, maybe 1 in the middle if it is a long strip.
Connect all the grounds, and power pins, using mostly a star configuration.
Then add the signal connections.
I like 3 different colors if possible, power, ground, signal.
Don't forget 0.1uF decoupling caps on all the ICs between power & ground.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Panici


Download the software from expresspb.com, really easy to use the pcb software to layout the chips and play with placement.


I'm most concerned with setting up buses and wiring everything. Can expresspb do that?


I find wirewrapping digital circuits with lots of connections is a great way to go as well. Line up the parts with shared connections, and just go pin to pin to pin, highlighting them on a paper schematic as you go.


Looks like an interesting prospect. I've got all the parts right now to solder though. So I might as well go that route.

Electrical Engineering Student

Grumpy_Mike

Quote
I'm most concerned with setting up buses and wiring everything.

Don't be, just treat them as point to point connections there is nothing special about it.
Lay out the major components and if the strips make the connections then it's a bonus, otherwise wire up the connections point to point with wires.

Panici


Quote
I'm most concerned with setting up buses and wiring everything.

Don't be, just treat them as point to point connections there is nothing special about it.
Lay out the major components and if the strips make the connections then it's a bonus, otherwise wire up the connections point to point with wires.


So I solder the components to the board first, and then heat that solder up again and attach the wires? What gauge is usually used?

Electrical Engineering Student

Grumpy_Mike

What I do is to fix the IC socket by just soldering opposite corners. Then solder it when I do the wires. However if you need to add a wire then you can do by remelting the joints.
I leave two holes free to each side of every IC connector, that way you can always track back and add another wire to any node. I use wire as thin as you can get 0.2mm is good. For a prototype board I use solid strand wire but if a cable has to flex at all then I use multi stranded.

dc42

As an alternative to perfboard you can use stripboard, which has buses already. There are programs such as VeroDes that you can use to design the layout.
Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

ajofscott

wire wrap wire avail in a variety of colors is thin flexible and strips easily. Who says you can't solder it! Use a 25W or less iron until you get really good at soldering. Solder in a moderate temp room ie 70ish F, have a clean damp rubber sponge, not an acrylic sponge, the latter will melt thus defeating the purpose of dabbing the iron tip.

Techone

@dc42

Thank for the tip. I search for "VeroDes", and I have download the instalation program. A "vero" can be easilly made by making a DYI PCB in a "vero" design.

@Panici

I know one thing... it is not going to be an easy job to solder/wire. You just simply need to be patience and methodical about it.

Panici


Download the software from expresspb.com, really easy to use the pcb software to layout the chips and play with placement.


Easier to use then EagleCAD? I've started messing around with it EagleCAD a little.


Don't be, just treat them as point to point connections there is nothing special about it.
Lay out the major components and if the strips make the connections then it's a bonus, otherwise wire up the connections point to point with wires.

Gotcha.

So I should grab some 30awg wire then? Anyone have a good source for cheap wire? I'd like to get a bunch of different colors, and I don't need that much length of each.
Electrical Engineering Student

CrossRoads

For layouts of hand assembled boards, I think yes. Count the number of holes you have available and drag the corners to match.
Drop in the parts for the sizes you will use, put the pins on the dots. No need to hunt all thru eagle to find the right part - just drop in a generic package.  Can have the parts layed out in no time, print it, and start wiring.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Panici


For layouts of hand assembled boards, I think yes. Count the number of holes you have available and drag the corners to match.
Drop in the parts for the sizes you will use, put the pins on the dots. No need to hunt all thru eagle to find the right part - just drop in a generic package.  Can have the parts layed out in no time, print it, and start wiring.


Ok, i'll give it a shot!


So I should grab some 30awg wire then? Anyone have a good source for cheap wire? I'd like to get a bunch of different colors, and I don't need that much length of each.
Electrical Engineering Student

CrossRoads

Hmm, never tried soldering 30 guage, only wirewrapped that small. Not sure how the insulation would hold up with heat when there is so little of it.

This might work, look around see if you have similar handy.

http://www.dipmicro.com/store/WIRE24
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

winner10920

For small wire like that you are probably better off getting stranded wire not solid, solid wire has a tendency to break at the ends easily, and its a pain to have to resolder it back on
stranded is more flexible which I find easier to route around, and it wont break so long as you strip it fine without nicking the wires,

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