4
\$\begingroup\$

N.B: I'm still a 14 years old boy that is just a beginner in electrical engineering.

I started a project with my Dad which was a "matrix clock ." We used 3 red led matrixes which are driven by several 74HC595n shift registers.

We made the code, uploaded it to a micro-controller, tested it on a bread board and it works sucssesfuly.

When we started designing the single sided PCB we decided that we would just do a module of three led matrixes aligned together connected to shift registers, so that we can use it as a screen for any thing, not just for the clock.

We used Easyeda as it is the most famous online schematic & PCB designer.

I made a schematic and converted it into PCB, layed out the parts properly (as I think) and started auto-routing (as it is very hard for me to route each connection manually.)

Remember that : I am using single sided pcb.

Every time the auto-router fails to route, even when we changed the layout of the elements.

At this point we got stuck, and we don't know what to do.

Does anyone have any suggestions?

Edit in Question : If there is any components required like jumbers,sockets,wires It will be nice to tell me how to use them.

This is my Schematic.

Very bad. I'm sorry, still learning.

enter image description here

Edit in Question : This is another Schematic I done today, no difference in connection but the difference in arrangement, color and in the Data header (I hope you understand me more clearly via this image):

enter image description here

This is one of my PCB layouts:

enter image description here

If there are any suggestions please tell me.

Links :

N.B: Sorry again if the homepage isn't properly setup because I don't know yet how to use Easyeda.

Here some project links on the website so that you can access the PCB & the Schematics and see them lively:

Links : (Edited due to some changes)

\$\endgroup\$
  • 3
    \$\begingroup\$ Auto routers are usually harder to use than just routing manually. Single sided boards with many components are hard to route in any case. You will get better results routing by hand, and just might not be possible without using jumpers. \$\endgroup\$ – JRE May 27 '18 at 12:51
  • 6
    \$\begingroup\$ Your schematics look better than many others that have been posted here. \$\endgroup\$ – JRE May 27 '18 at 12:59
  • 2
    \$\begingroup\$ Use a double-sided board, it will be much easier to route and will cost about the same to have made. \$\endgroup\$ – Leon Heller May 27 '18 at 13:28
  • 2
    \$\begingroup\$ The green wires might not be too bad but the blues have many cross-overs. I don't know if it is possible with the chips you have chosen but one trick is to rewire the blue wires in an order that suits the PCB. You then need to "rewire the code" for the data that is being sent to the displays. For example, if the columns were 'abcdefgh' but you wired them 'abcdhgfe' then your code would need to reverse the last four bits so that the display is correct. \$\endgroup\$ – Transistor May 27 '18 at 14:10
  • 2
    \$\begingroup\$ 2/2 For a 2-layer board, lay the power pins out first (high currents! pay attention to current flows!) and run the traces in a grid, mostly horizontal on one side, and mostly vertical on the other. DON'T forget to add bypass capacitors for each chip, and I suggest leaving some pads for an RC on each clock where it enters the board. Because of transients. \$\endgroup\$ – Spehro Pefhany May 27 '18 at 15:26
1
\$\begingroup\$

I do not think you can do this with a single sided board.

If it is at all possible on a single sided board, then you will have to use jumpers.

A jumper is a piece of wire that you solder in place like a resistor. It allows you to "jump over" (hence the name) other traces.

So, you would route as many traces as possible.

Then you see if you can route the remaining traces by using jumpers.

If you can do it at all, you will need a lot of jumpers on a single sided board.

If you could switch to a double sided board, it will be much easier to route - though I think you will probably need a few jumpers even on a double sided board.

As mentioned in the comments, a doubled sided board costs about the same as a single sided if you have it manufactured.


If you make it yourself at home, then you will probably have to stick with single sided. You will have a lot of holes to drill - for each IC pin and connector and every jumper.

The solder pads will have to be a bit larger than usual to allow you to drill the holes.

You will need very small drill bits, and a drill that rotates smoothly. A drill press like you would use for metal or wood working with typical drill bits (1mm and larger) typically wobbles a good bit - often times, the wobble will be as large as the diameter of the drill bits you would use to drill holes in a PCB. That would cause the drill press to break the bits.

You will also need to make the board somewhat larger to have space for the jumpers.


A board with jumpers looks like this:

enter image description here

Image borrowed from this other question.


As for how to accomplish a single sided board with jumpers, I think Peter Bennett has the best idea:

Route the board double sided, and arrange all the top side traces to be short, in groups, and in easy to reach spaces.

That automatically sets the vias and the drill holes where you need them.

Basically, you route a double sided board, but don't print or etch the top side.

All of the top side traces are replaced with wires.

With a little care, you can make it look nice and neat - and, more importantly, be easy to finish when soldering in your short wires on the top side. Neat doesn't just look good. It also helps with "easy to build."

\$\endgroup\$
  • \$\begingroup\$ I appreciate your answer but good to know that actually when i auto-route with double face PCB to see how it will end up if i used double sided PCB it routed successfully in less than a minute , but in the single side PCB it routed 80%> in 10 mins< ,then a message with "Time out" is shown on the screen.A comment on "- though I think you will probably need a few jumpers even on a double sided board." \$\endgroup\$ – Shams El-Deen May 27 '18 at 14:22
  • \$\begingroup\$ JRE,Could you tell me how to use jumpers its new for me I know only jumber wires. ? (describe it as a part of your answer). it can solve my problems. \$\endgroup\$ – Shams El-Deen May 27 '18 at 15:36
  • 1
    \$\begingroup\$ @ShamsEl-Deen: to make a single-side board with jumpers, as JRE shows, I would design it as a double-sided board with the tracks on the non-copper side side arranged as short straight segments, like the jumper wires in JRE's photo. That way the PCB program will place pads for you to solder the jumpers to without you having to modify the schematic to get the extra pads. \$\endgroup\$ – Peter Bennett May 27 '18 at 15:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.