Embedded Systems

Geoff Graham

Dr. Walker

12/14/2013

Final Part A

System Drawing-

Functions of each component-

-On/Off Switch- turns the device on/off. This can be used at any time during the running/stopping of the program.

-Key Pad- (Can be on laptop like original project) This will be used in starting and stopping the data collection and processing. Unless otherwise specified, we will initialize this with ‘start’ and ‘stop’ keys.

-Accelerometer- The accelerometer will be for measuring the body displacement of the vehicle. This accounts for change of the body based on suspension.

-Double Integration- This is to integrate the acceleration to linear outputs for further calculations

-Laser- This sensor will be used to measure the displacement of the vehicle to the ground. This works in conjunction with the accelerometer and distance encoder to create the most accurate and synchronized profile measurements.

-High Pass Filter- The High Pass Filter is used to attenuate the low frequencies or long wavelengths measured by the accelerometer.

-Distance Encoder- Measures the distance traveled and synchronizes the computed profile to that distance.

-LED Display- Simply displays the output of the profile.

Discussion of timer setting for real-time clock and the A/D channels and sampling rates-

The RS232 requires a line voltage of at least +/- 3 Volts and the PIC accepts 0-5 Volts. There is a sampling rate of 60-300 pulses a second.

Identifications of all off chip components needed- The main off chip component needed would be a reducer to reduce voltage from 10V to 5V because that is the maximum voltage the PIC18 can handle. Other off-chip components include

-accelerometer

-laser

-PSU

Estimate of the time required to digitize the two channels- 3000Hz = 1Cycle/1Second 3000Hz*1sec = 1Cycle. 1Cycle/3000Hz = 1 sec .333ms for the time to digitize the channels.

Estimate of time required to send the computed profile to the client via the serial port-

Baud Rate...