Recently, I was going through the pile of old projects which I had made when I had just got into electronics. I found a 24 x 6 LED matrix which was my first ‘complete’ project. A lot of messy wiring, not perfect but it still works fine. At the time I made this project, I never thought about the components which were used, how did they work, etc. I just wanted to complete it as soon as possible and have some fun. And I’m sure there are many like me.
One such component used in the LED matrix was 74HC595 which is a Shift Register. Yet another popular device which is used when you run out of output pins. There are 24 columns which need to be controlled individually which means that you need 24 output pins on the Arduino (or any other microcontroller) which is a lot and makes the wiring messy. That is why shift registers are used. Now we can control 24 rows (or more) by using just 5 pins on the Arduino. Clever, isn’t it?
In my previous Instructable, I made an LCD Trainer Kit which won a First Prize in Electronics Tips and Tricks Contest. It got some lovely comments from the people which suggests that the idea of getting back to basics is great.
In this Instructable, let us look at the working of a shift register and at the end build a small kit to see shift register in action.
Let’s get back to basics!”

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