started on 2014 cape code
diff --git a/bbb_cape/src/cape/robot_comp.c b/bbb_cape/src/cape/robot_comp.c
new file mode 100644
index 0000000..bf417e9
--- /dev/null
+++ b/bbb_cape/src/cape/robot_comp.c
@@ -0,0 +1,36 @@
+#include "cape/robot.h"
+
+#include <STM32F2XX.h>
+
+#include "cape/encoder.h"
+#include "cape/analog.h"
+#include "cape/digital.h"
+#include "cape/util.h"
+
+// TIM11.1 on PB9
+
+static volatile uint32_t ultrasonic_pulse_length = 0;
+
+void TIM1_TRG_COM_TIM11_IRQHandler(void) {
+ TIM11->SR = ~TIM_SR_CC1IF;
+ ultrasonic_pulse_length = TIM11->CCR1;
+}
+
+void robot_init(void) {
+ gpio_setup_alt(GPIOB, 11, 3);
+ RCC->APB2ENR |= RCC_APB2ENR_TIM11EN;
+ TIM11->CR1 = TIM_CR1_URS;
+ TIM11->SMCR = 5 << 4 /* TI1 */ |
+ 4 << 0 /* reset and start on edge */;
+ TIM11->DIER = TIM_DIER_CC1IE;
+ TIM11->CCMR1 = TIM_CCMR1_CC1S_0 /* input pin 1 -> timer input 1 */;
+ TIM11->CCER = TIM_CCER_CC1P /* go on falling edge */;
+ TIM11->EGR = TIM_EGR_UG;
+ TIM11->PSC = 1200 - 1; // 100kHZ timer
+ TIM11->CR1 |= TIM_CR1_CEN;
+ NVIC_SetPriority(TIM1_TRG_COM_TIM11_IRQn, 3);
+ NVIC_EnableIRQ(TIM1_TRG_COM_TIM11_IRQn);
+}
+
+void robot_fill_packet(struct DataStruct *packet) {
+}