1 files changed, 53 insertions, 0 deletions
diff --git a/ppmsum.cpp b/ppmsum.cpp
new file mode 100644
index 0000000..7b77036
--- /dev/null
+++ b/ppmsum.cpp
@@ -0,0 +1,53 @@
+#include "ppmsum.h"
+
+PPMSum* PPMSum::self = 0;
+
+template<>
+void interrupt<Interrupt::TIM4>() {
+	PPMSum::self->irq();
+}
+
+void PPMSum::irq() {
+	int16_t sr = TIM4.SR;
+	TIM4.SR = 0;
+	
+	if(sr & 0x06) {
+		GPIOA.ODR = 1 << 5;
+	} else {
+		GPIOA.ODR = 0;
+	}
+	
+	
+	if(sr & 0x01) {
+		// Timeout.
+		
+		// TODO: Indicate failsafe.
+		
+	} else if(sr & 0x02) {
+		// Period.
+		
+		if(TIM4.CCR1 > 5000) {
+			index = 0;
+		} else {
+			index++;
+		}
+		
+	} else if(sr & 0x04) {
+		// Pulsewidth.
+		
+		channels[index] = TIM4.CCR2;
+	}
+}
+
+void PPMSum::enable() {
+	RCC.enable(RCC.TIM4);
+	TIM4.PSC = 36;
+	TIM4.CCMR1 = 0x0201;
+	TIM4.SMCR = 0x54;
+	TIM4.CCER = 0x31;
+	TIM4.DIER = 0x07;
+	
+	Interrupt::enable(Interrupt::TIM4);
+	
+	TIM4.CR1 = 0x05;
+}