How To Write Analog Output In Arduino Uno R3 Board?

Ok so looking on the hardware we have for this phase, if you remember in step-1 we used two digital switches that are controlling the leds over here. The first one is being used test the all leds, every click will turn that on and off, and the second one is another digital input switch to run wave that is going up and down every time. I am clicking on that button. Now as you see i added two additional sensors, simple sensors that are called potentiometers, that a variable resistors meaning you can go hand and change the resistance of that potentiometer, and because each potentiometer is actually, connected with 3 connectors

I just put that below the breadboard and that's the wire over here. Ok running to the breadboard, now the connections that we have to the two sides are ground and power, and the middle one, this one is going into the, arduino analog input pins, in that case a0 and the next one is a1 for the, second potentiometer. And beacuse of that evey time that i will play with, the potentiometer, i will get different resistance, and of course different levels of voltages that the, arduino will see in the input pin, that's the all idea, and based on that value you can do something

In our case we would like to play with brightness and speed of the leds. However in this step, step-2a we would like only, to change something in the potentiometer, and see the result in our serial monitoring screen, in our computer and that is we are going do to, and of course the first thing is to go and upload sketch, so i will go into the arduino ide

Click on "upload" on the sketch that we saw, you will see that the rx and tx leds are blinking very quickly, and it is ready, loaded into the board, now we can see and play with the result.

So the first thing i would like to do is to start testing the range of what the potentiometer is actually providing,, so i will rotate each potentiometer completely to one side, in that case to the left side, and run the animation wave button, and if you remember, in that function i am actually printing something to the screen, into the serial monitoring screen, and i am looking right now and i see that i am, getting speed 0 (or close to 0) and brightness 0 that's the minimum value the potentiometer will provide us. If i will go again and turn that a little bit to the right, and this one maybe a little bit more and run that again, and i will get some value to the speed and value for the brightness, and if i will rotate completely to the maximum, to the right side each one of them and run that again. Ok that's is what we are going to see as a result that i am getting the maximum expected value:1023.

How To Write Analog Output In Arduino Uno R3 Board?

Digital signal has two states: 0v or 5v or any other voltage referance, and as part of the step-1 we already saw that digital pins support input and output. In addition, as part of this step, step-2 part a we already used analog pins as input.

Now, what if we would like to output a voltage other than 0v and 5v, meaning any value between them, like for example: 2.8v

Well, we can’t do it directly in arduin, unless we will use some external digital-to-analog converter (dac). So how we will be able to adjust the brightness of the leds if we have just 0v or 5v, that will be like on and off. I am very optimistic guy so don’t worry. The good news is that we can “get very close” to generating analog output value by using a method that is called pwm, while using a function called analogwrite(). Now let’s start with understanding what is PWM?