Accelerometers - MDHSRobotics/TeamWiki GitHub Wiki

Definition

an instrument for measuring acceleration, typically that of an automobile, ship, aircraft, or spacecraft, or that involved in the vibration of a machine, building, or other structure.

What is it useful for?

an accelerometer can help your project understand its surroundings better:

  • Is it driving uphill?
  • Is it going to fall over when it takes another step?
  • Is it flying horizontally or is it dive bombing your professor?

How do they work?

Accelerometers are electromechanical devices that sense either static or dynamic forces of acceleration. Static forces include gravity, while dynamic forces can include vibrations and movement.

How to connect to an Accelerometer

For most accelerometers, the basic connections required for operation are power and the communication lines. For Example with Arduino

Communication Interface

Accelerometers will communicate over an analog, digital, or pulse-width modulated connection interface.

  • Accelerometers with an analog interface show accelerations through varying voltage levels. These values generally fluctuate between ground and the supply voltage level. An ADC on a microcontroller can then be used to read this value. These are generally less expensive than digital accelerometers.

  • Accelerometers with a digital interface can either communicate over SPI or I2C communication protocols. These tend to have more functionality and be less susceptible to noise than analog accelerometers.

  • Accelerometers that output data over pulse-width modulation (PWM) output square waves with a known period, but a duty cycle that varies with changes in acceleration.

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