JAVA 555 timer with Raspberry Pi

Hello there,

This lesson is actually working fine with the documentation and code provided. However I added a few modifications to make it easier to understand how it works.

First I added a LED to the output in Pin 3 to check at what exact moment the code should increase the counter. With the values of the resistors and capacitors used in the example it is quite a challenge to visualise the square wave of the output without an oscillator. And this being a beginners kit I am not quite sure how in the documentation they assume I will have an oscillator. Well yes, I could prepare a software based oscillator, but that is another matter, for now I do not have any of those fancy equipment. I am just an electronics beginner student.

Anyway, I googled some 555 timer documentation and I found this web as a grate resource to fully understand the most well known 555 timer circuits. Also to help on the calculations of the frequency output this other web its really useful.

On the image bellow you can see the modifications and the final values that I used to get a frequency output wave of about 1 MHz. This is about 1 blink per second.

You can find the the Java code implementation of the lesson using ISR at pin 0 in this repository. That is all for now, I will move on to the next exercise and come back soon with more stuff.

For full details about how to set up your Raspberry Pi and how to run these exercises please check out my old post Raspberri Pi with Pi4j and Junit testing mockups. Or leave me a comment if you have any issue or question. 

Posted by Marc Andreu.