ultra.c

#include "ultra.h"

/// initialization HRS04 variables
void init_hrsd04_variable(HRS04_VAR* sen){
    sen->cap_rising_edge  = 0;
    sen->cap_falling_edge = 0;
    sen->pulse_width      = 0;
    sen->capture          = false;
    sen->distance         = false;
}

/// generate the input signal
void Triger_InputSig(HRS04_VAR* sen){
    GPIO_SetBits(sen->trig_port, sen->trig_pin);
    delay_us(10);
    GPIO_ResetBits(sen->trig_port, sen->trig_pin);
}

void ultra_setup(HRS04_VAR* sen)
{
    GPIO_InitTypeDef         GPIO_InitStructure;
    NVIC_InitTypeDef         NVIC_InitStructure;
    TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
    TIM_ICInitTypeDef        TIM_ICInitStructure;

    // RCC Configuration
    RCC_APB2PeriphClockCmd(sen->trig_rcc, ENABLE);

    // GPIO Output for Trigger
    GPIO_InitStructure.GPIO_Pin   = sen->trig_pin;
    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_Out_OD;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(sen->trig_port, &GPIO_InitStructure);

    // TIMx Ch1 (sen->timer_pin)
    GPIO_InitStructure.GPIO_Pin   = sen->timer_pin;
    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_IPU;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(sen->timer_port, &GPIO_InitStructure);

    // RCC Configuration
    RCC_APB1PeriphClockCmd(sen->timer_rcc, ENABLE );

    // Enable the TIMx global Interrupt
    NVIC_InitStructure.NVIC_IRQChannel                   = sen->timer_irq;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority        = 1;
    NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    /* Time base configuration */
    TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
    // Generate 1usec timer using 72 MHz clock
    TIM_TimeBaseStructure.TIM_Prescaler     = (uint16_t) (SystemCoreClock / 1000000) - 1;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode   = TIM_CounterMode_Up;
    TIM_TimeBaseInit(sen->timer, &TIM_TimeBaseStructure);

    /* PWM1 Mode configuration: Channelx */
    TIM_ICInitStructure.TIM_ICPolarity  = TIM_ICPolarity_Rising;
    TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
    TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
    TIM_ICInitStructure.TIM_ICFilter    = 0x0;
    TIM_ICInitStructure.TIM_Channel     = sen->timer_inp_channel;
    TIM_ICInit(sen->timer, &TIM_ICInitStructure);

    TIM_Cmd(sen->timer, ENABLE);

    TIM_ITConfig(sen->timer, sen->timer_cc_channel, ENABLE);

    init_hrsd04_variable(sen);
}