8-LED Display For Breadboarding

8-LED Display For Breadboarding

Postby Joseph Watson » Wed Apr 15, 2015 5:15 am

I think that just about every 28-pin PIC chip that is available in DIP form has an 8-bit port with the 8 associated pins all in a row. Typically, it is port B. The larger 40-pin models have such ports as well. If you are experimenting with such PIC chips in a solderless breadboard, here is a simple gadget you can make that creates an 8-LED display for such ports. It is one of those obvious things once you see it.

When a PIC chip has been plugged into a breadboard (or in many cases, when a small development board is plugged into a breadboard), this gizmo can be plugged in right along side it and the black wire pushed into a ground bus, saving all the fiddling with the individual resistors and LEDs.
8-LED Display front.jpg
8-LED Display front.jpg (42.79 KiB) Viewed 2955 times
8-LED Display back.jpg
8-LED Display back.jpg (31.43 KiB) Viewed 2955 times
NCR once refused to hire me because I was too short. I'm still waiting on my growth spurt.
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Re: 8-LED Display For Breadboarding

Postby Trevor » Mon Apr 01, 2019 12:58 pm

I bought a few of these from Tindie.

16_LEDs_PCB.jpg (40.54 KiB) Viewed 1878 times

https://www.tindie.com/products/madworm ... indicator/

As variation on the theme, I used different colour LEDs in the top and bottom rows. Why 2 rows of LEDs for only 8 channels? Simple! If you use the common-anode configuration, one row lights up. If you use the common-cathode configuration, the other row lights up.

Assembling this from parts was a little challenging - the 0805 LEDs were OK, it was the two 1206 resistor arrays on the back of the PCB with 4 pins either side which were a pain to hand solder.
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Re: 8-LED Display For Breadboarding

Postby t1d » Mon Sep 16, 2019 2:23 am

This is a good tip! I have made up several plug in breadboard devices... 10K pot, piezo speaker, DIY inductors, single LED/resistor combo, 9v battery clip, etc...

By being ready to go, the devices save time, of course, but they also eliminate the need to proof new components before employing them. I have a whole bunch of resistors that I only use with the bread board, because I know that they are working. And, bread boarding mistakes can stress components, so I don't use the bread board components in the final design, if I can help it. Economics come into play, here. After a design is proven on the bread board, I proof the new components that will go into the actual circuit.
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