Added solutions for many of the first exercises

1 files changed, 65 insertions, 0 deletions

diff --git a/sem4/embedded/m5/m5.ino b/sem4/embedded/m5/m5.ino
new file mode 100644
index 0000000..496e33b
--- /dev/null
+++ b/sem4/embedded/m5/m5.ino
@@ -0,0 +1,65 @@
+#include <krnl.h>
+#define STACK 200
+
+char stk1[STACK];
+char stk2[STACK];
+struct k_t *tsk1, *tsk2, *sem;
+
+unsigned long shared1 = 0;
+unsigned long shared2 = 0;
+
+#define DELAY 100000
+void f1() {
+	for(;;) {
+        for (int i = 0; i < DELAY/4; i++);
+        unsigned long s1 = shared1;
+
+        // Lock
+        k_wait(sem, 0);
+        unsigned long s2 = shared2;
+        // Unlock
+        k_signal(sem);
+
+        if (s1 != 0) {
+            Serial.print("S1: "); Serial.println(s1);
+        }
+        if (s2 != 0) {
+            Serial.print("S2: "); Serial.println(s2);
+        }
+	}
+}
+
+void f2() {
+	for(;;) {
+        shared1 += 1;
+        for (int i = 0; i < DELAY; i++);
+        shared1 -= 1;
+
+        // Lock
+        k_wait(sem, 0);
+        shared2 += 1;
+        for (int i = 0; i < DELAY; i++);
+        shared2 -= 1;
+        // Unlock
+        k_signal(sem);
+	}
+}
+
+void setup() {
+    pinMode(13, OUTPUT);
+    Serial.begin(115200);
+    Serial.println("Starting");
+
+    k_init(2, 1, 0);
+
+    sem = k_crt_sem(1, 1);
+
+    tsk1 = k_crt_task(f1, 10, stk1, STACK);
+    tsk2 = k_crt_task(f2, 10, stk2, STACK);
+
+    k_start(1); 
+}
+
+void loop() {
+
+}