Add exam for lsm

1 files changed, 272 insertions, 0 deletions

diff --git a/Year_3/LSM/exam.c b/Year_3/LSM/exam.c
new file mode 100644
index 0000000..fca2061
--- /dev/null
+++ b/Year_3/LSM/exam.c
@@ -0,0 +1,272 @@
+#include "stm32_unict_lib.h"
+#include <ctype.h> /* For isdigit() */
+#include <stdio.h>
+#include <stdlib.h> /* For atoi() */
+#include <string.h>
+
+typedef int electr_users_t;
+
+typedef enum {
+    IDLE, /* Init state */
+    CONSUME_ALL, /* Press X */
+    CONSUME_PER_SECOND, /* Press Y */
+    CONFIG, /* Press T */
+} status_t;
+
+electr_users_t electr_user[2];
+status_t status = IDLE;
+short switch_on = 0; /* Press Z */
+int consumption = 0;
+float consumption_per_second = 0.0;
+int threshold = 3000; /* Start value */
+short counter_over_threshold = 0;
+short alarm_on = 0;
+
+float
+calculate_consume_per_second()
+{
+    /* E = P * t
+     * where E is kW/h, P is kW and t is hours
+     * `energy_hours` is kWh
+     */
+    float energy_hours = ((electr_user[0] + electr_user[1]) / 1000.0) * ((1 / 60.0) / 60.0);
+
+    return energy_hours * 3600;
+}
+
+int
+get_new_threshold()
+{
+    char string[4];
+    char ch;
+    int i;
+    int error;
+    int num;
+
+    memset(string, 0, 4);
+
+    do {
+        printf("\nAdd a threshold in [0, 3000]: ");
+        fflush(stdout);
+
+        error = 0;
+        for (i = 0; i < 4; ++i) {
+            ch = readchar();
+
+            if (ch == 13) {
+                if (i == 0) {
+                    error = 1;
+                } else {
+                    string[i] = '\0';
+                }
+
+                break;
+            } else if (!isdigit(ch)) {
+                error = 1;
+                break;
+            }
+
+            __io_putchar(ch);
+            string[i] = ch;
+        }
+
+        if (error) {
+            printf("\nEnter a number.");
+            num = 3001;
+        } else {
+            /* `num` can't be < 0 because '-' is not a valid character */
+            num = atoi(string);
+        }
+    } while (num > 3000);
+
+    return num;
+}
+
+void
+init()
+{
+    DISPLAY_init();
+
+    GPIO_init(GPIOB);
+    GPIO_init(GPIOC);
+
+    GPIO_config_input(GPIOB, 10);
+    GPIO_config_EXTI(GPIOB, EXTI10);
+    EXTI_enable(EXTI10, FALLING_EDGE);
+
+    GPIO_config_input(GPIOB, 4);
+    GPIO_config_EXTI(GPIOB, EXTI4);
+    EXTI_enable(EXTI4, FALLING_EDGE);
+
+    GPIO_config_input(GPIOB, 5);
+    GPIO_config_EXTI(GPIOB, EXTI5);
+    EXTI_enable(EXTI5, FALLING_EDGE);
+
+    GPIO_config_input(GPIOB, 6);
+    GPIO_config_EXTI(GPIOB, EXTI6);
+    EXTI_enable(EXTI6, FALLING_EDGE);
+
+    GPIO_config_output(GPIOB, 0);
+    GPIO_config_output(GPIOC, 3);
+
+    TIM_init(TIM2);
+    TIM_set(TIM2, 0);
+    /* TIM2 is 32-bits */
+    /* (42000/84e3) * 2000 = 1000 ms */
+    TIM_config_timebase(TIM2, 42000, 2000);
+    TIM_enable_irq(TIM2, IRQ_UPDATE);
+    TIM_on(TIM2);
+
+    ADC_init(ADC1, ADC_RES_8, ADC_ALIGN_RIGHT);
+    ADC_channel_config(ADC1, GPIOC, 0, 10);
+    ADC_channel_config(ADC1, GPIOC, 1, 11);
+    ADC_on(ADC1);
+
+    CONSOLE_init();
+}
+
+int
+main()
+{
+    int adc_read;
+    char s[5];
+
+    init();
+
+    for (;;) {
+        ADC_sample_channel(ADC1, 11);
+        ADC_start(ADC1);
+        while (!ADC_completed(ADC1))
+            ;
+        adc_read = ADC_read(ADC1);
+        electr_user[0] = (adc_read * 500 / 255);
+
+        ADC_sample_channel(ADC1, 10);
+        ADC_start(ADC1);
+        while (!ADC_completed(ADC1))
+            ;
+        adc_read = ADC_read(ADC1);
+        electr_user[1] = (adc_read * 1000 / 255);
+
+        switch (status) {
+        case CONSUME_ALL:
+            /* Handle the case if the integer value is greater
+             * than the maximum length of the screen.
+             * In that case use KWatt
+             */
+
+            if (consumption <= 9999) {
+                sprintf(s, "%4d", consumption);
+            } else {
+                sprintf(s, "%4f", consumption / 1000.0);
+            }
+            break;
+        case CONSUME_PER_SECOND:
+            sprintf(s, "%4f", consumption_per_second);
+            break;
+        case CONFIG:
+            threshold = get_new_threshold();
+            status = IDLE;
+            counter_over_threshold = 0;
+            break;
+        default:
+            memset(s, ' ', 4);
+        }
+
+        DISPLAY_puts(0, s);
+    }
+
+    return 0;
+}
+
+void
+EXTI15_10_IRQHandler(void)
+{
+    if (EXTI_isset(EXTI10)) {
+        /* X */
+
+        if (status != CONFIG) {
+            status = CONSUME_ALL;
+        }
+
+        EXTI_clear(EXTI10);
+    }
+}
+
+void
+EXTI9_5_IRQHandler(void)
+{
+    if (EXTI_isset(EXTI6)) {
+        /* T */
+
+        status = CONFIG;
+
+        EXTI_clear(EXTI6);
+    }
+
+    if (EXTI_isset(EXTI5)) {
+        /* Z */
+
+        if (status != CONFIG) {
+            switch_on = !switch_on;
+
+            /* GPIO_toggle() does not assure 1 for ON and 0 for OFF */
+            if (switch_on) {
+                alarm_on = 0;
+                counter_over_threshold = 0;
+                GPIO_write(GPIOB, 0, 0); /* Turn off red led */
+                GPIO_write(GPIOC, 3, 1);
+            } else {
+                status = IDLE;
+                GPIO_write(GPIOC, 3, 0);
+            }
+
+            consumption = 0;
+            consumption_per_second = 0;
+        }
+
+        EXTI_clear(EXTI5);
+    }
+}
+
+void
+EXTI4_IRQHandler(void)
+{
+    if (EXTI_isset(EXTI4)) {
+        /* Y */
+
+        if (status != CONFIG) {
+            status = CONSUME_PER_SECOND;
+        }
+
+        EXTI_clear(EXTI4);
+    }
+}
+
+void
+TIM2_IRQHandler(void)
+{
+    if (TIM_update_check(TIM2)) {
+        if (!alarm_on && status != CONFIG) {
+            if (switch_on) {
+                int current_watts = (electr_user[0] + electr_user[1]);
+                consumption += current_watts;
+
+                if (current_watts > threshold) {
+                    counter_over_threshold++;
+
+                    if (counter_over_threshold > 10) {
+                        alarm_on = 1;
+                        GPIO_write(GPIOB, 0, 1); /* Turn on red led */
+                        GPIO_write(GPIOC, 3, 0); /* Turn off green led */
+                        switch_on = 0;
+                    }
+                }
+
+                consumption_per_second = calculate_consume_per_second();
+            }
+        }
+
+        TIM_update_clear(TIM2);
+    }
+}