How to detect max value of real time data in an array

[Mohan1]

I have connected a sine wave of amplitude 3V with 1.5V shifted above the zero to 12-bit ADC channel by using dsPIC33FJ32MC204 controller and stored in an array. I want to detect the max value out of five samples because after the five samples my data is repeating, so please give me any suggestion on it. I am getting output as a zero.

[sanju]

#define arrayLength 5

unsigned int array[arrayLength];                                //Array values should be updated with ADC values.

unsigned int i, max = 0;

void main()

{

for(i=0;i<sizeof(array)/sizeof(array[0]);i++)

{

if(array[i] > max)

{

max = array[i];

}

}

//here after the loop completion you can get the maximum value in variable max

}

You can find max number in a array by this way.

[Mohan1]

@sanju​ Thanks for your quick response sir and your logic is working properly and getting max value accurately but facing one problem that as data is real time ,so how can i take infinite data in array means how can i update array values with ADC values?

Thanks in advance.

[sanju]

First of all, you can't store infinite data in array because RAM size of your device is 2 KB. so you have to define arrayLength

#define arrayLength 5(you have to set it first).

suppose you have this define it as 8

then code like this

#define arrayLength 8

unsigned int array[arrayLength];                                //Array values should be updated with ADC values.

unsigned int i=0, max = 0;

void main()

{

while(1)

{

if(i<arrayLength )

{

//Read adc value and assign in array

array[i] = adc_value;

i++;

}

if(i == arrayLength )

{

for(i=0;i<sizeof(array)/sizeof(array[0]);i++)

{

if(array[i] > max)

{

max = array[i];

}

}

//here after the loop completion you can get the maximum value in variable max

i=0;

//Read adc value and assign in array

array[i] = adc_value;

i++;

}

// do your other tasks here

//Put some delay if required between adc samples.

}

}