Task 4.4.4 Solution
main.cpp
- Committer:
- noutram
- Date:
- 2017-07-13
- Revision:
- 1:f0954f86b4f2
- Parent:
- 0:83a9911ab6ec
File content as of revision 1:f0954f86b4f2:
#include "mbed.h"
//Function prototype
void doSample1Hz();
//Global objects
Serial pc(USBTX, USBRX);
AnalogIn POT_ADC_In(A0);
DigitalOut led(LED1);
#define N 16
//Shared variables
volatile static unsigned short sample16 = 0;
unsigned int sum = 0;
unsigned int count = 0;
//The ticker, used to sample data at a fixed rate
Ticker t;
//Main function
int main()
{
//Set baud rate to 115200
pc.baud(115200);
//Set up the ticker - 100Hz
t.attach(doSample1Hz, 0.01);
while(1) {
//Sleep
sleep();
//Add new sample to the sum
sum += sample16;
//Increment the count
count++;
//Enough to calculate the average?
if (count == N) {
//Divide sum by 16
unsigned short mean = (sum >> 4);
//Display
pc.printf("Mean = %hu\n", mean);
//Reset sum and count
count = sum = 0;
}
} //end while(1)
} //end main
//ISR for the ticker - simply there to perform sampling
void doSample1Hz()
{
//Toggle on board led
led = !led;
//READ ADC as an unsigned integer.
//Shift right 4 bits (this is a 12bit ADC) & store in static global variable
sample16 = POT_ADC_In.read_u16() >> 4;
}
Nicholas Outram