Interfacing of Digital Accelerometer to ADSP-21369

Evaluation Board

By:S.Chandramouli(10UQ1A0450)K.Pranava teja(10UQ1A0440)K.Srikanth(10UQ1A0441)M.Abishek(10UQ1A0449)

CONTENTSwhat is a Digital Accelerometer.

ADXL345 3-axis digital accelerometer.

I2C interface.

ADSP-21369 architecture

Interface ADXL345 to ADSP-21369

Tools-VDSP++

Applications

what is a Digital Accelerometer.

Accelerometer is an electromechanical device that will measure

acceleration forces.

It detects if the device is tilted to particular angle so that device can

change the application view.

It also determines whether the device is falling.

Features The ADXL345 is well suited for mobile device applications.

It measures the static acceleration of gravity in tilt-sensing applications, as

well as dynamic acceleration resulting from motion or shock.

Its high resolution (4 mg/LSB) enables measurement of inclination

changes less than 1.0°.

Free-fall sensing detects if the device is falling

ADXL345 3-axis digital accelerometer.The ADXL-345 is a small, thin, low power, 3-axis accelerometer with

high resolution (13-bit) measurement at up to ±16 g.

ADSP-21369 architectureThe third generation of SHARC Processors offers increased

performance, audio and application focused peripherals, and new

memory configurations.

It supports (SIMD) core with both 32-bit fixed-point and floating point

arithmetic formats.

It increases performance to 333MHz .

The ADSP-21369 increases the amount of on-chip memory to 2Mb

SRAM and 6Mb ROM.

I2C interface.The I²C bus is commonly used to connect relatively low-speed sensors

and other peripherals.

I²C is extremely popular due to its ease-of-use and ability to control

multiple peripherals while utilizing only two pins on the host controller.

Interface ADXL345 to ADSP-21369

The ADXL345 which is 3 axis accelerometer is connected to the ADSP-

21369 using the I2C bus, the ADSP processor is connected to the target

board using the RS-232 which acts like a USB.

Whenever the accelerometer is tilted it measures the static as well as

the dynamic changes in the acceleration due to gravity .

Rs-232

The processor has a flash memory in which the required program for

the target device is stored.

Whenever the accelerometer is moved the corresponding values are

checked to that of the values in the program and the corresponding

output is executed.

The serial communication interface RS-232 acts as the communication

medium between the target board and the PC.

Applications Because of these features, the use of accelerometers is increasing rapidly in

the applications that includes :

Mobiles and tablets

Handsets

Medical instrumentation

Gaming and pointing devices

Industrial implementation

Personal navigation devices

Any Queries