1 files changed, 39 insertions, 0 deletions
diff --git a/powerswitch2/main.c b/powerswitch2/main.c
new file mode 100644
index 0000000..63e5d5c
--- /dev/null
+++ b/powerswitch2/main.c
@@ -0,0 +1,39 @@
+#include <avr/io.h>
+#include <util/delay.h>
+
+static inline void uart_init();
+int main()
+{
+    /* serial */
+    uart_init();
+
+    /* data input */
+    PORTB &= ~0x0F;
+    DDRB  |=  0x0F;
+
+    for (;;)
+    {
+        while ((UCSRA & (1 << RXC)) == 0);
+        PORTB ^= UDR & 0x0F;
+
+        while ((UCSRA & (1 << UDRE)) == 0);
+        UDR = PORTB & 0x0F;
+    }
+
+    return 0;
+}
+
+static inline void uart_init()
+{
+    UCSRB |= (1 << RXEN)  | (1 << TXEN);
+    UCSRC |= (1 << UCSZ0) | (1 << UCSZ1);
+#define BAUD 38400
+#include <util/setbaud.h>
+    UBRRH = UBRRH_VALUE;
+    UBRRL = UBRRL_VALUE;
+#if USE_2X
+    UCSRA |= (1 << U2X);
+#else
+    UCSRA &= ~(1 << U2X);
+#endif
+}