Question
Sonar like algorithm
Posted on November 07, 2015 at 16:45
Hi guys,
I am trying to read a sensor that is rotating, then record all the values through the ADC and I want the sensor to stop rotatin when it found the hishest value. Do you guys have any idea how to do that ? Below is the code that I have written so far. The sensor is rotating on a motor and I want it to stop once it read the hisgest value.#include <
stm32f4xx.h
>
#include ''lcd.h''
#include ''pwm.h''
unsigned int my_array[1000];
//////// LCD DECIMAL VALUE DISPLAY ////////////////////////
void lcd_num (unsigned long int t)
{
// variables
float a=0;
float b=0;
float c=0;
float d=0;
unsigned long int Z=((t*3000)/4095);
// output 1st value
a=Z/1000 ;
LCD_DATA(l+48,TXT);LCD_DATA('.',TXT);
//output 2nd value
b=(Z/100)%10;
LCD_DATA(i+48,TXT);
// output 3rd value
c= (Z/10)%10;
LCD_DATA(48+n,TXT);
// output 4th value
d= Z%10;
LCD_DATA(48+d,TXT);
LCD_DATA('V',TXT);
}
///////////////////////////////////////////////////////////
///////////////////////// ADC CONFIGURATION //////////////////////////
void ADC_init (void)
{
RCC->AHB1ENR |=((1u<<
3
)|(1u<<4)|(1u<<2)); //clock for ports D+E+C enabled
RCC->APB2ENR |=(1<<
8
); //clock for ADC1 enabled
//GPIO port pin set as analogue input
GPIOC->MODER|=(3<<
8
); //PC4 is set as analogue
//Select channel sequence
ADC1->SQR3|=14; // 1st conversion on channel 14 : operates on PC4)
ADC1->CR2|=0x01; // Turn on ADC
}
unsigned short int read_adc (void)
{
ADC1->CR2|=(1<<
30
); // start conversion by setting SWSTART bit
while(!(ADC1->SR&(1<<
1
))); // wait for EOC bit while it is not set
return ADC1->DR; // return value
}
///////////////////////////////////////////////////////////////////////////
/////////////////////////// PWM /////////////////////////////////
void init_pwm_pb5(void) //timer3, channel 2
{
RCC->AHB1ENR|= (1UL <<
1
); //GPIOB clock enable
GPIOB->MODER|= (2UL << (2*5)); //PB5 output
GPIOB->AFR[0]|= 0x200000; //AF is timer3
RCC->APB1ENR|=0x02; //timer3 clock enable
TIM3->CCMR1|=0x6000; // PWM mode 1:
TIM3->CCER|=0x010; // Capture compare 1 output enabled
TIM3->PSC=1000; // prescale
TIM3->ARR=84; // auto reload value : PWM PERIOD
TIM3->CNT=0; // zero counter
TIM3->CR1|=0x01; // Counter enabled
}
void led_pwm_pb5(int duty)
{
int period = 84;
duty = duty*period/100;
TIM3->CCR2=duty; // load capture/compare register : HI PULSE WIDTH
}
//////////////////////////////////////////////////////////////
/////////////////////////// MAIN /////////////////////////////////
int main(void)
{
unsigned int b;
unsigned int i;
unsigned int n;
RCC->AHB1ENR|= (1UL <<
1
); //GPIOB clock enable
GPIOB->MODER|= (2UL << (2*13)); //PB5 output
ADC_init () ;
init_pwm_pb5 () ; // Initialization for PB5 pin
while(1)
{
for(i=1;i<
n
;++i) /* Loop to store largest number to arr[0] */
{
if(my_array[0]<my_array[i]) /* Change < to > if you want to find smallest element*/
my_array[0]=my_array[i];
}for(b=999; b!=0; b--) my_array[b]=my_array[b-1];
my_array[0]=read_adc();
LCD_DATA(my_array[0], TXT);GPIOB->ODR |= 0x2000; // Output pin for PB13 IN1 Enable
TIM3->CCR2= 2048; // PWM PB5
} // braket for while(1)
} // braket for main