efm32_7segment_display_demo.c

#include "em_system.h"
#include "em_emu.h"
#include "em_cmu.h"
#include "em_device.h"
#include "em_chip.h"
#include "em_gpio.h"

#include <stdlib.h>
#include <stdint.h>

typedef uint8_t         u08;
typedef struct {
    GPIO_Port_TypeDef port;
    unsigned int pin;
} gpio_pin_t;


void init_clocks(void);
void init_gpio(void);

void __delay_ms(uint32_t milliseconds);
void setup_systick_timer(void);
uint32_t get_systick(void);

volatile uint32_t systick_count = 0;
uint32_t clock_freq;

#define delay(MS)   __delay_ms(MS)
#define millis()    get_systick()


// $[User-defined pin name abstraction]

#define GPIO_PA2_PIN        (2)
#define GPIO_PA2_PORT       (gpioPortA)

#define GPIO_PB11_PIN       (11)
#define GPIO_PB11_PORT      (gpioPortB)

#define GPIO_PC13_PIN       (13)
#define GPIO_PC13_PORT      (gpioPortC)

#define GPIO_PC14_PIN       (14)
#define GPIO_PC14_PORT      (gpioPortC)

#define GPIO_PC15_PIN       (15)
#define GPIO_PC15_PORT      (gpioPortC)

#define GPIO_PD5_PIN        (5)
#define GPIO_PD5_PORT       (gpioPortD)

#define GPIO_PD6_PIN        (6)
#define GPIO_PD6_PORT       (gpioPortD)

#define GPIO_PD7_PIN        (7)
#define GPIO_PD7_PORT       (gpioPortD)

#define GPIO_PE10_PIN       (10)
#define GPIO_PE10_PORT      (gpioPortE)

#define GPIO_PE11_PIN       (11)
#define GPIO_PE11_PORT      (gpioPortE)

#define GPIO_PE12_PIN       (12)
#define GPIO_PE12_PORT      (gpioPortE)

#define GPIO_PE13_PIN       (13)
#define GPIO_PE13_PORT      (gpioPortE)

#define HFXO_N_PIN          (14)
#define HFXO_N_PORT         (gpioPortB)

#define HFXO_P_PIN          (13)
#define HFXO_P_PORT         (gpioPortB)

#define LFXO_N_PIN          (8)
#define LFXO_N_PORT         (gpioPortB)

#define LFXO_P_PIN          (7)
#define LFXO_P_PORT         (gpioPortB)

// [User-defined pin name abstraction]$

//
// PINS ORDER: A, B, C, D, E, F, G, DP
//
const gpio_pin_t segment_pins[] = {
    {GPIO_PE12_PORT, GPIO_PE12_PIN},    // A = PE12
    {GPIO_PD6_PORT,  GPIO_PD6_PIN},     // B = PD6
    {GPIO_PC13_PORT, GPIO_PC13_PIN},    // C = PC13
    {GPIO_PA2_PORT,  GPIO_PA2_PIN},     // D = PA2
    {GPIO_PD5_PORT,  GPIO_PD5_PIN},     // E = PD5
    {GPIO_PE11_PORT, GPIO_PE11_PIN},    // F = PE11
    {GPIO_PC14_PORT, GPIO_PC14_PIN},    // G = PC14
    {GPIO_PB11_PORT, GPIO_PB11_PIN},    // DP = PB11

};

const gpio_pin_t digit_pins[] = {
    {GPIO_PC15_PORT, GPIO_PC15_PIN},    // DIG4 = PC15
    {GPIO_PD7_PORT,  GPIO_PD7_PIN},     // DIG3 = PD7
    {GPIO_PE10_PORT, GPIO_PE10_PIN},    // DIG2 = PE10
    {GPIO_PE13_PORT, GPIO_PE13_PIN},    // DIG1 = PE13
};


//
// BIT ORDER(MSB): A, B, C, D, E, F, G, DP
//
const u08 number_code[10] = {
    0b11111100, //0
    0b01100000, //1
    0b11011010, //2
    0b11110010, //3
    0b01100110, //4
    0b10110110, //5
    0b10111110, //6
    0b11100000, //7
    0b11111110, //8
    0b11110110, //9
};


__STATIC_INLINE void pin_hi(gpio_pin_t p)
{
    GPIO_PinOutSet(p.port, p.pin);
}


__STATIC_INLINE void pin_lo(gpio_pin_t p)
{
    GPIO_PinOutClear(p.port, p.pin);
}


__STATIC_INLINE void pin_write(gpio_pin_t p, u08 value)
{
    if (value)
        pin_hi(p);
    else
        pin_lo(p);
}


__STATIC_INLINE void display_digit1(u08 number)
{
    u08 ncode = number_code[number];

    for (int i = 0; i < 8; i++) {
        pin_write(segment_pins[i], (ncode & 0x80));
        ncode <<= 1;
    }
}


__STATIC_INLINE void display_digit4(int number)
{
    for (int i = 0; i < 4; i++) {
        pin_lo(digit_pins[i]);
        pin_hi(digit_pins[(i + 3) % 4]);

        display_digit1(number % 10);
        number /= 10;

        __delay_ms(2);      // delay millisecons
    }
}


__STATIC_INLINE void display_7segment_led(int number, uint32_t ms)
{
    uint32_t tick = get_systick();

    while ((get_systick() - tick) < ms)
        display_digit4(number);
}


/**************************************************************************//**
 * @brief  Main function
 *****************************************************************************/
int main(void)
{
    /* Chip errata */
    CHIP_Init();

    init_clocks();
    init_gpio();

    for (int i = 0; i < 4; i++)
        pin_hi(digit_pins[i]);

    setup_systick_timer();

    __delay_ms(2000);

    /* Infinite loop */
    while (1) {
        for (int n = 0; n < 10000; n++) {
            display_7segment_led(n, 100);
        }
    }
}


void init_clocks(void)
{
    /* ----------------------------------- */
    /* INIT HFXO                           */
    /* ----------------------------------- */
    CMU->CTRL = (CMU->CTRL & ~_CMU_CTRL_HFXOMODE_MASK) | CMU_CTRL_HFXOMODE_XTAL;

    CMU->CTRL = (CMU->CTRL & ~_CMU_CTRL_HFXOBOOST_MASK)
            | CMU_CTRL_HFXOBOOST_50PCENT;

    SystemHFXOClockSet(32000000);

    /* ----------------------------------- */
    /* INIT LFXO                           */
    /* ----------------------------------- */
    CMU->CTRL = (CMU->CTRL & ~_CMU_CTRL_LFXOMODE_MASK) | CMU_CTRL_LFXOMODE_XTAL;
    // [Use oscillator source]$

    // $[LFXO Boost Percent]
    CMU->CTRL = (CMU->CTRL & ~_CMU_CTRL_LFXOBOOST_MASK)
            | CMU_CTRL_LFXOBOOST_100PCENT;

    /* ----------------------------------- */
    /* INIT CLOCKS                         */
    /* ----------------------------------- */
    // $[LFXO enable]
    CMU_OscillatorEnable(cmuOsc_LFXO, true, true);
    
    // $[HFXO enable]
    CMU_OscillatorEnable(cmuOsc_HFXO, true, true);
        
    // $[High Frequency Clock select]
    /* Using HFXO as high frequency clock, HFCLK */
    CMU_ClockSelectSet(cmuClock_HF, cmuSelect_HFXO);

    /* Enable peripheral clock */
    CMU_ClockEnable(cmuClock_HFPER, true);

    /* Enable clock for GPIO by default */
    CMU_ClockEnable(cmuClock_GPIO, true);
}


void init_gpio(void)
{

    // $[Port A Configuration]

    /* Pin PA2 is configured to Push-pull */
    GPIO->P[0].MODEL = (GPIO->P[0].MODEL & ~_GPIO_P_MODEL_MODE2_MASK)
            | GPIO_P_MODEL_MODE2_PUSHPULL;
    // [Port A Configuration]$

    // $[Port B Configuration]

    /* Pin PB11 is configured to Push-pull */
    GPIO->P[1].MODEH = (GPIO->P[1].MODEH & ~_GPIO_P_MODEH_MODE11_MASK)
            | GPIO_P_MODEH_MODE11_PUSHPULL;
    // [Port B Configuration]$

    // $[Port C Configuration]

    /* Pin PC13 is configured to Push-pull */
    GPIO->P[2].MODEH = (GPIO->P[2].MODEH & ~_GPIO_P_MODEH_MODE13_MASK)
            | GPIO_P_MODEH_MODE13_PUSHPULL;

    /* Pin PC14 is configured to Push-pull */
    GPIO->P[2].MODEH = (GPIO->P[2].MODEH & ~_GPIO_P_MODEH_MODE14_MASK)
            | GPIO_P_MODEH_MODE14_PUSHPULL;

    /* Pin PC15 is configured to Push-pull */
    GPIO->P[2].MODEH = (GPIO->P[2].MODEH & ~_GPIO_P_MODEH_MODE15_MASK)
            | GPIO_P_MODEH_MODE15_PUSHPULL;
    // [Port C Configuration]$

    // $[Port D Configuration]

    /* Pin PD5 is configured to Push-pull */
    GPIO->P[3].MODEL = (GPIO->P[3].MODEL & ~_GPIO_P_MODEL_MODE5_MASK)
            | GPIO_P_MODEL_MODE5_PUSHPULL;

    /* Pin PD6 is configured to Push-pull */
    GPIO->P[3].MODEL = (GPIO->P[3].MODEL & ~_GPIO_P_MODEL_MODE6_MASK)
            | GPIO_P_MODEL_MODE6_PUSHPULL;

    /* Pin PD7 is configured to Push-pull */
    GPIO->P[3].MODEL = (GPIO->P[3].MODEL & ~_GPIO_P_MODEL_MODE7_MASK)
            | GPIO_P_MODEL_MODE7_PUSHPULL;
    // [Port D Configuration]$

    // $[Port E Configuration]

    /* Pin PE10 is configured to Push-pull */
    GPIO->P[4].MODEH = (GPIO->P[4].MODEH & ~_GPIO_P_MODEH_MODE10_MASK)
            | GPIO_P_MODEH_MODE10_PUSHPULL;

    /* Pin PE11 is configured to Push-pull */
    GPIO->P[4].MODEH = (GPIO->P[4].MODEH & ~_GPIO_P_MODEH_MODE11_MASK)
            | GPIO_P_MODEH_MODE11_PUSHPULL;

    /* Pin PE12 is configured to Push-pull */
    GPIO->P[4].MODEH = (GPIO->P[4].MODEH & ~_GPIO_P_MODEH_MODE12_MASK)
            | GPIO_P_MODEH_MODE12_PUSHPULL;

    /* Pin PE13 is configured to Push-pull */
    GPIO->P[4].MODEH = (GPIO->P[4].MODEH & ~_GPIO_P_MODEH_MODE13_MASK)
            | GPIO_P_MODEH_MODE13_PUSHPULL;
    // [Port E Configuration]$
}



/******************************************************************************
 * @brief Delay function
 *****************************************************************************/
void __delay_ms(uint32_t milliseconds)
{
    uint32_t start_tick = get_systick();
    while ((get_systick() - start_tick) < milliseconds) {
    }
}


void setup_systick_timer(void)
{
    clock_freq = CMU_ClockFreqGet(cmuClock_CORE);
    /* Enable SysTick interrupt, necessary for __delay_ms() */
    if (SysTick_Config(CMU_ClockFreqGet(cmuClock_CORE) / 1000)) while (1) ;
    NVIC_EnableIRQ(SysTick_IRQn);
}


uint32_t get_systick(void)
{
    return systick_count;
}

/******************************************************************************
 * SYSTICK ISR
 *****************************************************************************/
void SysTick_Handler(void)
{
    systick_count++;
}