Arduino SPI tutorial 22/4/22 74HC595

1

In this project there are 13 leds. Of those, 6 leds are not powered.
why is that so?
Thanks.

2

Hi @Brenton472

are you referring to this guide?

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There are 8 LEDs being used, because this is an 8-bit shift register.

3

Yes it is! So how do the other 6 leds shown as unwired on the breadboard come into play?

4

Perhaps you are misinterpreting the diagram, which would be easy to do since it is a little cramped

There are a total of 8 LEDs in the above diagram

There are two groups of 4 LEDs, and each group is made up of alternating red and blue LEDs.

You can count the wires, which are also in two groups of 4

There are also 8 Resistors, one for each LED to limit the LED current.

5

Thanks, now I see what is going on.

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6

If you need further info about 74HC595, you can see here: Introduction to 74HC595 - The Engineering Projects
Here you can find the pinout and all other necessary info regarding the chip.It is basically a shift register. It has an ability to store and to shift the data of 8 bits.

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