From 87f55b05f3fb3f7164594362d95f205569c5e6b5 Mon Sep 17 00:00:00 2001
From: Santo Cariotti <santo@dcariotti.me>
Date: Wed, 26 Jan 2022 22:45:46 +0100
Subject: add exam

---
 Year_3/LSM/ex_20211122.c | 264 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 264 insertions(+)
 create mode 100644 Year_3/LSM/ex_20211122.c

(limited to 'Year_3')

diff --git a/Year_3/LSM/ex_20211122.c b/Year_3/LSM/ex_20211122.c
new file mode 100644
index 0000000..a7980e1
--- /dev/null
+++ b/Year_3/LSM/ex_20211122.c
@@ -0,0 +1,264 @@
+#include "stm32_unict_lib.h"
+#include <stdlib.h>
+#include <string.h>
+
+typedef enum {
+    FIRST = 2,
+    F_S,
+    SECOND,
+    S_T,
+    THIRD
+} floor_t;
+
+typedef enum {
+    CONFIG,
+    IDLE,
+    CLOSING,
+    RUNNING,
+    OPENING,
+} status_t;
+
+floor_t curr_floor = FIRST;
+floor_t next_floor = FIRST;
+short direction = 1;
+
+unsigned q_index = 0;
+floor_t* queue;
+
+status_t status = IDLE;
+
+short circular_200ms = 0; /* alternates 0 and 1 thanks to `0 ^ 1` */
+short handle_1500ms = 0; /* until 15, then restart */
+
+int time = 10; /* 10 * `time` = 1s */
+int lift_time;
+int time_i = 0;
+
+void
+init()
+{
+    int i;
+    queue = malloc(sizeof(floor_t) * 10);
+    for (i = 0; i < 10; ++i)
+        queue[i] = 0;
+
+    GPIO_init(GPIOB);
+    GPIO_init(GPIOC);
+
+    GPIO_config_input(GPIOB, 10); /* X */
+    GPIO_config_EXTI(GPIOB, EXTI10);
+    EXTI_enable(EXTI10, FALLING_EDGE);
+
+    GPIO_config_input(GPIOB, 4); /* Y */
+    GPIO_config_EXTI(GPIOB, EXTI4);
+    EXTI_enable(EXTI4, FALLING_EDGE);
+
+    GPIO_config_input(GPIOB, 5); /* Z */
+    GPIO_config_EXTI(GPIOB, EXTI5);
+    EXTI_enable(EXTI5, FALLING_EDGE);
+
+    GPIO_config_input(GPIOB, 6); /* T */
+    GPIO_config_EXTI(GPIOB, EXTI6);
+    EXTI_enable(EXTI6, FALLING_EDGE);
+
+    GPIO_config_output(GPIOC, 2); /* YELLOW */
+    GPIO_config_output(GPIOC, 3); /* GREEN */
+    GPIO_config_output(GPIOB, 0); /* RED */
+
+    DISPLAY_init();
+
+    CONSOLE_init();
+
+    TIM_init(TIM2);
+    TIM_set(TIM2, 0);
+    TIM_on(TIM2);
+    TIM_config_timebase(TIM2, 8400, 840);
+    TIM_enable_irq(TIM2, IRQ_UPDATE);
+
+    ADC_init(ADC1, ADC_RES_8, ADC_ALIGN_RIGHT);
+    ADC_channel_config(ADC1, GPIOC, 1, 11);
+    ADC_on(ADC1);
+    ADC_sample_channel(ADC1, 11);
+
+    ADC_start(ADC1);
+    while (!ADC_completed(ADC1))
+        ;
+    int adc_read = ADC_read(ADC1);
+    time = ((adc_read * (10 - 4) / 255.0) + 4);
+}
+
+int
+main()
+{
+    init();
+
+    char s[4];
+    int i;
+    int adc_read;
+
+    sprintf(s, "%3d ", curr_floor);
+
+    for (;;) {
+        ADC_start(ADC1);
+        if (status == CONFIG) {
+            while (!ADC_completed(ADC1))
+                ;
+            adc_read = ADC_read(ADC1);
+            time = ((adc_read * (10 - 4) / 255.0) + 4);
+            sprintf(s, "%f", time / 10.0);
+            DISPLAY_puts(0, s);
+        } else {
+            sprintf(s, "%3d%c", curr_floor / 2, ((curr_floor % 2) ? '-' : ' '));
+            DISPLAY_puts(0, s);
+            lift_time = (time / 10 / 2.0) / 0.1;
+        }
+    }
+
+    free(queue);
+    return 0;
+}
+
+void
+check_queue()
+{
+    int i;
+
+    for (i = q_index; i != (q_index - 1) % 10; i = (i + 1) % 10) {
+        if (queue[i] != 0) {
+            goto_floor(queue[i]);
+            queue[i] = 0;
+            return;
+        }
+    }
+
+    if (queue[i] != 0) {
+        goto_floor(queue[i]);
+        queue[i] = 0;
+    }
+}
+
+void
+    goto_floor(floor)
+{
+    status = CLOSING;
+    switch (floor) {
+    case 1:
+        next_floor = FIRST;
+        break;
+    case 2:
+        next_floor = SECOND;
+        break;
+    case 3:
+        next_floor = THIRD;
+        break;
+    }
+
+    if (curr_floor < next_floor) {
+        direction = 1;
+    } else if (curr_floor > next_floor) {
+        direction = -1;
+    } else {
+        direction = 0;
+    }
+}
+
+void
+    call_floor(floor)
+{
+    if (queue[(q_index - 1) % 10] == floor)
+        return;
+
+    if (status == IDLE) {
+        goto_floor(floor);
+    } else {
+        queue[q_index] = floor;
+        q_index = (q_index + 1) % 10;
+    }
+}
+
+void
+EXTI15_10_IRQHandler(void)
+{
+    if (EXTI_isset(EXTI10)) {
+        call_floor(1);
+        EXTI_clear(10);
+    }
+}
+
+void
+EXTI9_5_IRQHandler(void)
+{
+    if (EXTI_isset(EXTI5)) {
+        call_floor(2);
+        EXTI_clear(EXTI5);
+    }
+
+    if (EXTI_isset(EXTI6)) {
+        if (status == IDLE) {
+            status = CONFIG;
+        } else if (status == CONFIG) {
+            status = IDLE;
+        }
+        EXTI_clear(EXTI6);
+    }
+}
+
+void
+EXTI4_IRQHandler(void)
+{
+    if (EXTI_isset(EXTI4)) {
+        call_floor(3);
+        EXTI_clear(EXTI4);
+    }
+}
+
+void
+TIM2_IRQHandler(void)
+{
+    if (TIM_update_check(TIM2)) {
+        if (status == RUNNING) {
+            if (circular_200ms) {
+                GPIO_toggle(GPIOC, 2);
+            }
+
+            time_i++;
+
+            if (time_i >= lift_time) {
+                time_i = 0;
+                if (curr_floor == next_floor) {
+                    GPIO_write(GPIOC, 2, 0);
+                    status = OPENING;
+                    time_i = 0;
+                } else {
+                    curr_floor += direction;
+                }
+            }
+        } else if (status == CLOSING || status == OPENING) {
+            if (circular_200ms) {
+                if (status == CLOSING)
+                    GPIO_toggle(GPIOB, 0);
+                else
+                    GPIO_toggle(GPIOC, 3);
+            }
+
+            handle_1500ms++;
+            if (handle_1500ms == 15) {
+                if (status == CLOSING) {
+                    status = RUNNING;
+                } else {
+                    status = IDLE;
+                }
+
+                handle_1500ms = 0;
+                GPIO_write(GPIOB, 0, 0);
+                GPIO_write(GPIOC, 3, 0);
+
+                if (status == IDLE)
+                    check_queue();
+            }
+        }
+
+        circular_200ms ^= 1;
+        TIM_update_clear(TIM2);
+    }
+}
-- 
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