1 Chapter 3: Tilt with the Memsic Dual-Axis Accelerometer Smart Sensors and Applications Chapter 3: Tilt with the Memsic Dual-Axis Accelerometer Presented by: Andy Lindsay Parallax, Inc.

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3 Chapter 3, Pages The Memsic Dual-Axis Accelerometer

4 Chapter 3, Page 67

5 Chapter 3, Activity #1, Page 68 Circuit: Figure 3-3 on page 68 Program: SimpleTilt.bs2 on page 70. √ Follow the checkmarks on pages

6 Chapter 3, Activity #1, Page 70

7 Chapter 3, Activity #2, Pages Using SEROUT commands instead of DEBUG Circuit: Figure 3-6 and Figure 3-7, pages Program: SimpleTiltLcd.bs2, page 74 √ Follow the checkmarks on page 74.

8 Chapter 3, Activity #3, Pages Applying Scale and Offset: 1.Apply offset to align the input scale to zero. 2.Apply the scale. 3.Apply any additional offset needed for the output scale. Scaling/Offset from 1875 — 3125 to -127 — 127 Applying Scale/Offset to the value variable

9 Chapter 3, Activity #3, Pages Choosing the right ** Constant for Scaling… …and Clamping the Input Range with MIN and MAX

10 Chapter 1, Activity #1, Pages Program: TestScaleOffset.bs2 √ Follow the checkmarks on pages 78 – 80.

11 Chapter 3, Activity #3, Pages PBASIC and Negative Numbers Program:SignedNumbers.bs2 √ Follow the checkmark instructions on page 81.  In PBASIC, only Word variables can hold signed numbers, for example: value VAR Word  All signed numbers have 16 bits.  Look at Bit 15 of the variable to know if a signed number is negative or positive.  For example, if the variable value.bit15 is equal to 1, the number is negative.

12 Chapter 3, Activity #4, Page 84 Sample Readings at Various Orientations Scaling and Offset for 1/100 g. Program: SimpleTilt.bs2 √ Follow the checkmark instructions on page 85.

13 Chapter 3, Activity #5, Pages , Calculating Arctangent with ATN The result of an ATN operation is expressed in Brads (Binary Radians) Program: TestAtn.bs2, p. 90 √ Follow the checkmarks on page 89.

14 Chapter 3, Activity #5, Pages Converting from Brads to Degrees with the */ Operator angle = 361 */ angle The */ operator multiplies the operand by a number of 256 ths Program: BradsToDegrees.bs2, page 90 √ Follow the checkmarks on page 90.

15 Chapter 3, Activity #5, Page 92 Measuring Tilt Angle on the Vertical Plane

16 Chapter 3, Activity #5, Pages Program: VertWheelRotation.bs2, p. 95 √ Follow the checkmark on page 95.

17 Chapter 3, Activity #6, Page 99

18 Chapter 3, Activity #6, Pages Sine, Cosine and the Unit Circle Program: SineCosine.bs2, page 101 √ Follow checkmarks on pages 101 – 102. The SIN and COS operators return values from -127 to 127

19 Chapter 3, Activity #6, Pages Arcsine and Arccosine Subroutines Program: TestArcsine.bs2, page 103 √ Follow checkmarks on pages 103, 105.

20 Chapter 3, Activity #6, Page Displaying Accelerometer Tilt Angle Program: HorizontalTilt.bs2, page 108 √ Follow checkmarks on page 108.