Changed the prescaler to get the desired frequency.

src/darwin_imu.c

@@ -535,7 +535,7 @@ uint8_t imu_init(TMemory *memory,unsigned int ram_base_address)
   /* imu timer configuration */
   htim.Instance=IMU_TIMER;
   htim.Init.Period = 1000;
-  htim.Init.Prescaler = 84;
+  htim.Init.Prescaler = 36;
   htim.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
   htim.Init.CounterMode = TIM_COUNTERMODE_UP;
   htim.Init.RepetitionCounter=0;