1 files changed, 6 insertions, 0 deletions
diff --git a/tube-rotator/stepper.c b/tube-rotator/stepper.c
index 064db5a..a498b43 100644
--- a/tube-rotator/stepper.c
+++ b/tube-rotator/stepper.c
@@ -23,6 +23,7 @@
 #include <avr/sfr_defs.h>
 #include <avr/interrupt.h>
 #include <util/atomic.h>
+#include <math.h>
 
 #include "stepper.h"
 
@@ -125,3 +126,8 @@ uint16_t stepper_get_speed(void)
 {
   return target_speed;
 }
+
+uint8_t stepper_get_speed_rpm(void)
+{
+  return (uint8_t)lround( ( (double)F_CPU / (double)(51200 * (target_speed + 1) ) ) * 60.0 );
+}