Index: firmware/App/Controllers/DialInFlow.c
===================================================================
diff -u -rc3315e0cc263df74569bbb58591229418b50fe92 -r90945afbe3866bf383c44c2a1f52438192c267c5
--- firmware/App/Controllers/DialInFlow.c	(.../DialInFlow.c)	(revision c3315e0cc263df74569bbb58591229418b50fe92)
+++ firmware/App/Controllers/DialInFlow.c	(.../DialInFlow.c)	(revision 90945afbe3866bf383c44c2a1f52438192c267c5)
@@ -107,11 +107,12 @@
 #define DIP_ML_PER_MIN_TO_PUMP_RPM_FACTOR    ( DIP_REV_PER_LITER / ML_PER_LITER )
 #define DIP_GEAR_RATIO                       32.0F           ///< DialIn pump motor to dialIn pump gear ratio.
 #define DIP_PWM_ZERO_OFFSET                  0.1F            ///< 10% PWM duty cycle = zero speed.
+#define DIP_100_PCT_PWM_RPM_RANGE            4000.0F         ///< 10-90% PWM range yields 0-3,200 RPM range.  Full 100% PWM range would yield 4,000 RPM range.
 
 /// Conversion from PWM duty cycle % to commanded pump motor speed.  PWM range is 10% to 90%.  RPM range is 0 to 3200.  3200 / 0.8 = 4000.
-#define DIP_PWM_TO_MOTOR_SPEED_RPM(pwm,dir)  ( ( ((pwm) - DIP_PWM_ZERO_OFFSET) * 4000.0F ) * ( dir == MOTOR_DIR_FORWARD ? 1.0F : -1.0F ) )
+#define DIP_PWM_TO_MOTOR_SPEED_RPM(pwm,dir)  ( ( ((pwm) - DIP_PWM_ZERO_OFFSET) * DIP_100_PCT_PWM_RPM_RANGE ) * ( dir == MOTOR_DIR_FORWARD ? 1.0F : -1.0F ) )
 /// Conversion from pump motor speed to PWM duty cycle.
-#define DIP_MOTOR_SPEED_RPM_TO_PWM(rpm)      ( ( (F32)(rpm) / 4000.0F ) + DIP_PWM_ZERO_OFFSET )
+#define DIP_MOTOR_SPEED_RPM_TO_PWM(rpm)      ( ( (F32)(rpm) / DIP_100_PCT_PWM_RPM_RANGE ) + DIP_PWM_ZERO_OFFSET )
 // Macro converts PWM to estimate flow rate needed to achieve it.  TODO - this macro does not reverse the function that estimates PWM from target flow rate - and it should
 #define DIP_ML_PER_MIN_FROM_PWM(pwm)         ( (pwm) - DIP_PWM_ZERO_OFFSET ) / DIP_ML_PER_MIN_TO_PUMP_RPM_FACTOR / DIP_GEAR_RATIO / DIP_MOTOR_RPM_TO_PWM_DC_FACTOR