serial plot issues

Projects Programming
1

Hi

I am using atmega2560 to sample 50hz sine signal (at 1KHz) and plot it . The plot works fine when I print analog read function. I changed the code to take in 20 samples and then out of this loop print those 20 samples. To my surprise the wave is different from what I saw earlier. Why is it so? Snippet of my code below:

unsigned long curr, end;
void loop()
{
curr = micros();
if(curr - end >= 1000) // 1KHz sample
{
end = micros();
if(n<20)
{
value[n]=analogRead(analogInPin); //accumulate 20 samples - 20ms
n++;
}
else if (n==20) // plot samples after acquisition
{
for (n=0;n<20;n++)
{Serial.println(value[n]);} //Waveform in wierd
n=0;
}
}

2

Snippet of my code below:

Please post the whole program or a full cut down version that shows the problem.

3

Post all the code inside tags please,

4

Well this is the code. Nothing extra. Only analog pin is defined as A0

5

Well this is the code.

No. It is SOME of it. Where, in the snippet you posted, is the value array declared?

6

Yes array was declared as unsigned int values[30].

7

If you are going to post only some of your code, I'm only going to post some of my answer.

The values you are now sending are not equally spaced, time...