Powerpoint Gesture Recognition
- 2. - SARVESH SINGH 1403213090 1 © Technical Spark
- 8. Arduino • Open-Source Prototyping Platform Accelerometer • ADXL3xx Bluetooth • HC0x © Technical Spark
- 9. Gesture Control Wireless Communication Introduction ToAccelerometer What’s Inside Accelerometer?? Various Classifications Bluetooth Master Slave © Technical Spark
- 10. Gesture Control Wireless Communication Introduction To Accelerometer Various Classifications Bluetooth Master What’s Inside Accelerometer?? Slave © Technical Spark
- 11. –Howit works??? It All Begins Here… © Technical Spark
- 12. So, What is an accelerometer??? Simply stated … It is a device that measures acceleration forces. STATIC (due to gravity) DYNAMIC (w.r.tDevice) Measures the tilt of the device (w.r.t. gravity) Analyze the way device is moving Vibrations & Shocks © Technical Spark
- 13. So, What is an accelerometer??? To put simply… It is a device that measures acceleration forces. STATIC (due to gravity) DYNAMIC (w.r.tDevice) Measures the tilt of the device (w.r.t. gravity) Analyze the way device is moving Vibrations & Shocks © Technical Spark
- 14. Understanding Accelerometer Remember Hooke’s law: fk =kx = mg g=(kx)/m Now Somehow mechanical displacement electrical signal piezoelectric, piezoresistive or capacitive components © Technical Spark
- 15. These tiny crystal structures output electrical charge when placed under mechanical stress ( e.g. acceleration). Understanding Accelerometer © Technical Spark
- 16. So, How does it work??? © Technical Spark
- 17. An accelerometer works on the principle of piezo electric effect. Here, imagine a cuboidal box, having a small ball inside it, like in the picture above. The walls of this box are made with piezo electric crystals. Whenever you tilt the box, the ball is forced to move in the direction of the inclination, due to gravity. The wall with which the ball collides, creates tiny piezo electric currents. There are totally, three pairs of opposite walls in a cuboid. Each pair corresponds to an axis in 3D space: X, Y and Z axes. Depending on the current produced from the piezo electric walls, we can determine the direction of inclination and its magnitude. So, How does it work??? © Technical Spark
- 18. So, What is an accelerometer??? Simply stated… It is a ^ device that measures acceleration force electromechanical Another Classification Digital Accelerometer Vs Analog Accelerometer © Technical Spark
- 19. So, What is an accelerometer?? Simply stated… It is a ^ device that measures acceleration force electromechanical Another Classification Digital Accelerometer Vs Analog Accelerometer Digital accelerometers usually use pulse width modulation (PWM) for their output. This means there will be a square wave of a certain frequency, and the amount of time the voltage is high will be proportional to the amount of acceleration. © Technical Spark
- 20. So, What is an accelerometer?? Simply stated… It is a ^ device that measures acceleration force electromechanical Another Classification Digital Accelerometer Vs Analog Accelerometer Analog style accelerometers output a continuous voltage that is proportional to acceleration. E.g. 2.5V for 0g, 2.6V for 0.5g, 2.7V for 1g and so on. © Technical Spark
- 21. Digital Accelerometer + used when pure digital inputs are available in microcontroller + requires the knowledge of SPI(Serial PeripheralInterface) or I2C(Inter Integrated Circuit Communication) Analog Accelerometer + used when ADC inputs are available in microcontroller. + requires little knowledge of Programming acceleration=read_adc(); © Technical Spark
- 22. ?Digital Accelerometer + used when pure digital inputs are available in microcontroller. + requires the knowledge of SPI(Serial Peripheral Interface)or I2C(Inter Integrated Circuit Communication) Analog Accelerometer + used when ADC inputs are available in microcontroller. + requires little knowledge of Programming acceleration=read_adc(); --Values flicker a bit © Technical Spark
- 23. Two Axis Accelerometer Vs Three Axis Accelerometer Responds to change in value in only 2 axes . Corresponds to 4 different motion in space. (Still sufficient) © Technical Spark
- 24. Two Axis Accelerometer Vs Three Axis Accelerometer Responds to change in value in all 3 axes . Corresponds to all different motion in space. Cost is almost the same as Two Axis Accelerometer. © Technical Spark
- 25. Accelerometers : u have seen them everywhere Used in mobile phones here accelerometer is used to present landscape or portrait views of the device's screen In Cricket What about Cricket ??? In Laptops Many laptops feature an accelerometer which is used to detect drops. If a drop is detected, the heads of the hard disk are parked to avoid data loss and possible head or disk damage by the ensuing shock. © Technical Spark
- 26. CONCLUSIONS: How Should our Accelerometer be… ??? • It should measure both Static + Dynamic acceleration • It should be an analog one. • It should have 3 Axes. • Sensitivity should be high •ADXL335 © Technical Spark
- 27. ADXL335 Is Your Accelerometer Working Properly?? Set this pin to 3V, an electrostatic force is exerted on the accelerometer beam. Check the voltages Vx , Vy , Vz on X , Y and Z pins respectively. If Vx= --(0.325)V and Vy= +(0.325)V and Vz=+(.550)V . Accelerometer is working properly This ST pin can be left open-circuit or connected to common (COM) in normaluse © Technical Spark
- 28. Now That We Have Got Our Required Accelerometer WHAT’S NEXT?? Now we need to convert the available analog signal from accelerometer to digital signal. Use ADC Pins of ATMEGA 328(ARDUINO UNO) Connect Gnd & Vcc Use required Capacitors at X,Y & Z. © Technical Spark
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