varpa: initial public commit

1 files changed, 57 insertions, 0 deletions

diff --git a/firmware/src/peripheral/timer.c b/firmware/src/peripheral/timer.c
new file mode 100644
index 0000000..1caff1c
--- /dev/null
+++ b/firmware/src/peripheral/timer.c
@@ -0,0 +1,57 @@
+/**
+ * 
+ * Author: Dylan Muller
+ * Copyright (c) 2025 
+ * All rights reserved.
+ * 
+ * - Commercial/IP use prohibited.
+ * - Attribution required.
+ * See License.txt
+ *
+ */
+
+#include "setup.h"
+
+#include "peripheral/timer.h"
+
+#include <stdint.h>
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <util/atomic.h>
+
+uint32_t millis_count = 0;
+
+void timer_init(void)
+{
+    uint32_t ctc_overflow;
+
+    ctc_overflow = ((F_CPU / 1000) / 8); 
+    TCCR1B |= (1 << WGM12) | (1 << CS11);
+
+    OCR1AH = (ctc_overflow >> 8);
+    OCR1AL = ctc_overflow;
+
+    TIMSK1 |= (1 << OCIE1A);
+}
+
+void timer_reset(void)
+{
+    ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+        millis_count = 0;
+    }
+}
+
+uint32_t timer_millis(void)
+{   
+    uint32_t millis;
+
+    ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+    millis = millis_count;
+  }
+  return millis;
+}
+
+ISR(TIMER1_COMPA_vect)
+{
+    millis_count++;
+}