Friday, September 29, 2017

Charlieplexing 3 - hardware

This is the third installment about Charlieplexing.

After my first two stories which you can find by clicking here: and here: I got some questions about wiring this all up.

First lets look at the schematics again:

So we are looking at 5 pins from an Attiny85 or Arduino. At trhese 5 pins we will be soldering 20 leds !!! Now that sounds complicated but in real life isn't. So what's the trick.

Well I solder all to a stripboard like this:

Now look closely:

And it's obvious isn't it. The stripboard I am using and that I can strongly advise has long leads just like we need to solder all leds to. It resembles the schematics closely, which makes it easy to follow. The brand name is Velleman and their article number is 3164 however it can also easily be found at our favorite chinese suppliers.
We will solder one pin of the arduino to one end of a strip and another pin to another end of a strip.

Next we will have 5 lanes on which we can solder the leds accoriding to the schematic. Really a piece of cake.

As the stripboard is long enough we can easily use this for attaching 20 leds to an Attint85.
This will get more complicated if you want to make your project as compact as possible. But for the projects I am going to describe this setup is more as sufficient.

Next time I will give you a real project using this technique complete with a 3D printed housing.
So until then start soldering and make a prototype and start playing with the software to see what you can get out of this.

Till next time.
Have fun

Luc Volders