From 656ff2de2737d005c1de0b80cd293b6672bce8d8 Mon Sep 17 00:00:00 2001
From: Santo Cariotti <santo@dcariotti.me>
Date: Tue, 1 Feb 2022 16:17:17 +0100
Subject: add exam

---
 Year_3/LSM/ex_20200127.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 Year_3/LSM/ex_20200127.c

diff --git a/Year_3/LSM/ex_20200127.c b/Year_3/LSM/ex_20200127.c
new file mode 100644
index 0000000..e3c3348
--- /dev/null
+++ b/Year_3/LSM/ex_20200127.c
@@ -0,0 +1,98 @@
+#include "stm32_unict_lib.h"
+#include <string.h>
+
+typedef enum {
+    IDLE,
+    RAIN
+} status_t;
+
+status_t status = IDLE;
+int freq = 100;
+float dim;
+float tank = 0;
+
+void
+init()
+{
+    DISPLAY_init();
+    GPIO_init(GPIOB);
+    GPIO_config_input(GPIOB, 10);
+    GPIO_config_EXTI(GPIOB, EXTI10);
+    EXTI_enable(EXTI10, FALLING_EDGE);
+
+    GPIO_config_output(GPIOB, 0);
+
+    ADC_init(ADC1, ADC_RES_8, ADC_ALIGN_RIGHT);
+    ADC_channel_config(ADC1, GPIOC, 1, 11);
+    ADC_channel_config(ADC1, GPIOC, 0, 10);
+    ADC_on(ADC1);
+
+    TIM_init(TIM2);
+    TIM_set(TIM2, 0);
+    TIM_on(TIM2);
+    TIM_config_timebase(TIM2, 8400, 1000);
+    TIM_enable_irq(TIM2, IRQ_UPDATE);
+
+    CONSOLE_init();
+}
+
+int
+main()
+{
+    init();
+    char s[4];
+    int value;
+
+    for (;;) {
+        if (status == RAIN) {
+            if (tank > 30)
+                tank = 0;
+            ADC_sample_channel(ADC1, 11);
+            ADC_start(ADC1);
+            while (!ADC_completed(ADC1)) { }
+            value = ADC_read(ADC1);
+            freq = (value * 70 / 255 + 10) * 100;
+
+            ADC_sample_channel(ADC1, 10);
+            ADC_start(ADC1);
+            while (!ADC_completed(ADC1)) { }
+            value = ADC_read(ADC1);
+            dim = (value * 48 / 255.0 + 2) / 10;
+
+            sprintf(s, "%f", tank);
+        } else {
+            sprintf(s, "SUN ");
+        }
+        DISPLAY_puts(0, s);
+    }
+    return 0;
+}
+
+void
+EXTI15_10_IRQHandler(void)
+{
+    if (EXTI_isset(EXTI10)) {
+        if (status == IDLE) {
+            GPIO_write(GPIOB, 0, 1);
+            status = RAIN;
+        } else {
+            GPIO_write(GPIOB, 0, 0);
+            status = IDLE;
+        }
+
+        EXTI_clear(EXTI10);
+    }
+}
+
+void
+TIM2_IRQHandler(void)
+{
+    if (TIM_update_check(TIM2)) {
+        TIM2->ARR = freq;
+
+        if (status == RAIN) {
+            tank += dim;
+        }
+        TIM_update_clear(TIM2);
+    }
+}
-- 
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