diff --git a/2ano/2semestre/ac2/aula04/AC2-P-Aula04.pdf b/2ano/2semestre/ac2/aula04/AC2-P-Aula04.pdf
new file mode 100644
index 0000000..fb6e5c2
Binary files /dev/null and b/2ano/2semestre/ac2/aula04/AC2-P-Aula04.pdf differ
diff --git a/2ano/2semestre/ac2/aula04/part1-1.c b/2ano/2semestre/ac2/aula04/part1-1.c
new file mode 100644
index 0000000..bdba858
--- /dev/null
+++ b/2ano/2semestre/ac2/aula04/part1-1.c
@@ -0,0 +1,23 @@
+#include <detpic32.h>
+
+void delay(int ms) {
+    resetCoreTimer();
+    while (readCoreTimer() < ms * 20000);
+}
+
+int main() {
+    // Configure RB14 as output
+    TRISCbits.TRISC14 = 0;
+
+    while (1) {
+        // Wait 0.5s
+        delay(500);
+        // Update value
+        LATCbits.LATC14 = !LATCbits.LATC14;
+
+        // Print current value
+        printStr("RB14: ");
+        printInt10(LATCbits.LATC14);
+        putChar('\r');
+    }
+}
diff --git a/2ano/2semestre/ac2/aula04/part1-2.c b/2ano/2semestre/ac2/aula04/part1-2.c
new file mode 100644
index 0000000..d0adb19
--- /dev/null
+++ b/2ano/2semestre/ac2/aula04/part1-2.c
@@ -0,0 +1,22 @@
+#include <detpic32.h>
+
+void delay(int ms) {
+    resetCoreTimer();
+    while (readCoreTimer() < ms * 20000);
+}
+
+int main() {
+    // Configure RE6-RE3 as output
+    TRISE = TRISE & 0xFF87;
+    // Initialize the counter
+    unsigned int counter = 0;
+    
+    while (1) {
+        // Update value
+        LATE = (LATE & 0xFF87) // Reset bits 6-3
+               | counter << 3; // Merge with counter
+        
+        delay(460);
+        counter = (counter + 1) % 10;
+    }
+}
diff --git a/2ano/2semestre/ac2/aula04/part1-3.c b/2ano/2semestre/ac2/aula04/part1-3.c
new file mode 100644
index 0000000..983f017
--- /dev/null
+++ b/2ano/2semestre/ac2/aula04/part1-3.c
@@ -0,0 +1,22 @@
+#include <detpic32.h>
+
+void delay(int ms) {
+    resetCoreTimer();
+    while (readCoreTimer() < ms * 20000);
+}
+
+int main() {
+    // Configure RE6-RE3 as output
+    TRISE = TRISE & 0xFF87;
+    // Initialize the counter
+    unsigned int counter = 0;
+    
+    while (1) {
+        // Update value
+        LATE = (LATE & 0xFF87) // Reset bits 6-3
+               | counter << 3; // Merge with counter
+        
+        delay(370);
+        counter = (counter + 9) % 10;
+    }
+}