From 807e4c43bcb6496cd89a56227c15ca0d3bc4b999 Mon Sep 17 00:00:00 2001
From: Santo Cariotti <santo@dcariotti.me>
Date: Wed, 10 Nov 2021 11:02:02 +0100
Subject: lsm: add exercise

---
 Year_3/LSM/ex_20211110.c | 241 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 241 insertions(+)
 create mode 100644 Year_3/LSM/ex_20211110.c

(limited to 'Year_3')

diff --git a/Year_3/LSM/ex_20211110.c b/Year_3/LSM/ex_20211110.c
new file mode 100644
index 0000000..bba8665
--- /dev/null
+++ b/Year_3/LSM/ex_20211110.c
@@ -0,0 +1,241 @@
+#include "stm32_unict_lib.h"
+#include <stdio.h>
+#include <string.h>
+
+/* LED RED = PB0,
+ * LED YELLOW = PC2,
+ * LED GREEN = PC3,
+ * X = PB10,
+ * Y = PB4,
+ * Z = PB5,
+ * T = PB6
+ */
+
+#define TA_MIN 10
+#define TA_MAX 30
+#define CYCLE_50MS 12
+
+int config_state = 0;
+int config_ta = 0;
+int ta_time = TA_MIN;
+
+typedef enum {
+    AUTO,
+    HAND
+} modes_t;
+
+typedef enum {
+    CLOSED,
+    OPENING,
+    OPEN,
+    CLOSING
+} status_t;
+
+modes_t mode = AUTO;
+status_t status = CLOSED;
+
+char gate[4] = "----";
+
+int counter_open = 0;
+int counter_ta = 0;
+
+void
+dash(int n)
+{
+    int i;
+    for (i = 0; i < n; ++i)
+        *(gate + i) = '-';
+
+    for (i = n; i < 4; ++i)
+        *(gate + i) = ' ';
+}
+
+int
+main()
+{
+    GPIO_init(GPIOB);
+    GPIO_init(GPIOC);
+
+    GPIO_config_output(GPIOB, 0);
+    GPIO_config_output(GPIOC, 2);
+    GPIO_config_output(GPIOC, 3);
+
+    GPIO_config_input(GPIOB, 6);
+    GPIO_config_input(GPIOB, 10);
+    GPIO_config_input(GPIOB, 4);
+    GPIO_config_input(GPIOB, 5);
+
+    GPIO_config_EXTI(GPIOB, EXTI6);
+    EXTI_enable(EXTI6, FALLING_EDGE);
+
+    GPIO_config_EXTI(GPIOB, EXTI10);
+    EXTI_enable(EXTI10, FALLING_EDGE);
+
+    GPIO_config_EXTI(GPIOB, EXTI4);
+    EXTI_enable(EXTI4, FALLING_EDGE);
+
+    GPIO_config_EXTI(GPIOB, EXTI5);
+    EXTI_enable(EXTI5, FALLING_EDGE);
+
+    DISPLAY_init();
+    ADC_init(ADC1, ADC_RES_8, ADC_ALIGN_RIGHT);
+    ADC_channel_config(ADC1, GPIOC, 1, 11);
+    ADC_on(ADC1);
+    ADC_sample_channel(ADC1, 11);
+
+    /* Use one timer for:
+	 * OPENING time: 50 * 12 = 600ms
+	 *
+	 */
+    TIM_init(TIM2);
+    TIM_set(TIM2, 0);
+    TIM_on(TIM2);
+    TIM_enable_irq(TIM2, IRQ_UPDATE);
+    TIM_config_timebase(TIM2, 8400, 500); /* 50 ms */
+
+    int adc_read;
+    char buffer[4];
+
+    if (mode == HAND) {
+        GPIO_write(GPIOC, 2, 1);
+    }
+
+    for (;;) {
+        ADC_start(ADC1);
+        if (config_state) {
+            if (config_ta) {
+                while (!ADC_completed(ADC1)) { }
+                adc_read = ADC_read(ADC1);
+                ta_time = adc_read * (TA_MAX - TA_MIN) / 255 + TA_MIN;
+                sprintf(buffer, "  %2d", ta_time);
+            } else {
+                if (mode == AUTO) {
+                    sprintf(buffer, "AUTO");
+                } else {
+                    sprintf(buffer, "HAND");
+                }
+            }
+        } else {
+            strcpy(buffer, gate);
+        }
+        DISPLAY_puts(0, buffer);
+    }
+
+    return 0;
+}
+
+void
+EXTI9_5_IRQHandler(void)
+{
+    if (EXTI_isset(EXTI6)) {
+        config_state = !config_state;
+        if (!config_state) {
+
+            config_ta = 0;
+        }
+
+        GPIO_toggle(GPIOB, 0);
+        EXTI_clear(EXTI6);
+    }
+
+    if (EXTI_isset(EXTI5)) {
+        if (mode == HAND) {
+            if (status == CLOSED) {
+                status = OPENING;
+            } else if (status == OPEN) {
+                status = CLOSING;
+            }
+        }
+        EXTI_clear(EXTI5);
+    }
+}
+
+void
+EXTI15_10_IRQHandler(void)
+{
+    if (EXTI_isset(EXTI10)) {
+        if (config_state) {
+            config_ta = 1;
+        } else {
+            if (status == CLOSED) {
+                status = OPENING;
+            }
+        }
+        EXTI_clear(EXTI10);
+    }
+}
+
+void
+EXTI4_IRQHandler(void)
+{
+    if (EXTI_isset(EXTI4)) {
+        if (config_state) {
+            config_ta = 0;
+
+            if (mode == AUTO) {
+                mode = HAND;
+            } else {
+                mode = AUTO;
+            }
+
+            GPIO_toggle(GPIOC, 2);
+        }
+        EXTI_clear(EXTI4);
+    }
+}
+
+void
+TIM2_IRQHandler(void)
+{
+    if (status == CLOSED) {
+        GPIO_write(GPIOC, 3, 0);
+    } else if (status == OPEN) {
+        GPIO_write(GPIOC, 3, 1);
+    } else {
+        GPIO_toggle(GPIOC, 3);
+    }
+
+    if (status == OPEN) {
+        counter_ta++;
+        if (counter_ta >= ta_time * 10) {
+            counter_ta = 0;
+            status = CLOSING;
+        }
+    }
+
+    if (status == OPENING || status == CLOSING) {
+        counter_open++;
+        if (counter_open == CYCLE_50MS) {
+            if (status == OPENING) {
+                status = OPEN;
+            } else if (status == CLOSING) {
+                status = CLOSED;
+            }
+            counter_open = 0;
+        }
+
+        if (status == OPENING) {
+            if (counter_open <= CYCLE_50MS / 4) {
+                dash(3);
+            } else if (counter_open <= CYCLE_50MS / 3) {
+                dash(2);
+            } else if (counter_open <= CYCLE_50MS / 2) {
+                dash(1);
+            } else {
+                dash(0);
+            }
+        } else if (status == CLOSING) {
+            if (counter_open <= CYCLE_50MS / 4) {
+                dash(1);
+            } else if (counter_open <= CYCLE_50MS / 3) {
+                dash(2);
+            } else if (counter_open <= CYCLE_50MS / 2) {
+                dash(3);
+            } else {
+                dash(4);
+            }
+        }
+    }
+
+    TIM_update_clear(TIM2);
+}
-- 
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