MEC DAC D Mobile Electronic Communications Device Audio Capability Disabler

1
MEC DAC DMobile Electronic Communications Device
Audio Capability Disabler

• Thursday May 9th, 2002
• Stevens Institute of Technology
• Hoboken, NJ 07030

2
Team MEC DAC-D Members

• Faculty Advisor
• Professor Hongbin Li

• Team Student Members
• Ilan Sklar (Team Leader Head of EE Team)
• David Riley (Team EE member)
• Neal Snyder (Team CPE Leader)
• Seung Yoo (Team CPE member Head of Web
  Development)

3

Abstract
Existing Technology

• Bluelinx developing similar technology
  utilizing Bluetooth wireless modules.
  
• Bluetooth weaknesses
• Expensive
• Allowable radiation limits range of coverage

Our Design

• Utilize lower frequency transmitters
• Inexpensive parts
• Easily available
• Memory and timer
• Longer Range

4

Design Goals
Electrical Engineering

• Construction of Transmitters and Receivers
• Main system parameter is the range of the
  Transmitter and Receivers
  
• Utilize pre-fabricated modules and adjust them
  to our desired outputs.
  
• Chipset includes encoder, decoder and antenna
• Transmitter and Receiver equipped with four
  channels
  

5
Prototype Specifications
Electrical Engineering

• Utilizing pre-fabricated kits that can be
  adjusted to the projects desired needs.
  
• Transmitter module designed to receive digital
  serial data from the encoder and transmit an RF
  signal at 418 MHz.
  
• The Serial data is received and sent to the
  decoder

6
Prototype Specifications
Electrical Engineering
Transmitter (courtesy Glolab Co)

• Configured as encoder by connecting pin 7 to a
  voltage source.
  
• Pins 6, 10, 11, 12 and 13 are input pins with
  200 microampere pullup current sources. (terminal
  pins 0-4)
  
• Transmission initiated by pulling one of the
  inputs from LOW to Vss. (5V)
  
• Transmitter module receives digital serial data
  from the encoder and transmits at 418MHz.

7
Prototype Schematic
Electrical Engineering
Transmitter (courtesy Glolab Co)

8
Prototype Specifications
Electrical Engineering
Receiver (courtesy Glolab Co)

• Configured as decoder by connecting pin 7 to a
  voltage source.
  
• Serial data received by the RM1V module and
  feeds into input pin 13 on decoder.
  
• Addresses are selected by positions 1-4 of DIP
  switch SW5.
  
• These are compared with addresses received and
  if data is valid then it is sent to the decoder.
  
• Receiver outputs are connected to five NPN
  bipolar
  
• transistors that sink 400 milliamperes each.
• These transistors are controlled by position 5
  on the DIP switch, which can either be momentary
  or latched outputs.

9
Prototype Schematic
Electrical Engineering
Receiver (courtesy Glolab Co)

10
Assembly
Electrical Engineering

Transmitter

• Assembled in EE lab
• Prefabricated so just had to follow directions
• Needed 9V power supply
• Purchased enclosure and switches from radio shack

Receiver

• Assembled voltage divider using resistors and
  potentiometer
  
• Converted 12V power source to the necessary 5V
• Assembled another voltage divider to power the
  chip

11
Performance Evaluation

• Tested capabilities to see range and
  applicability
  
• Used LEDs to see that all 4 channels worked as
  Glolab had intended
  
• Tested range using 2-way radios while walking
  around
  
• Testing of the prototype proved successful up
  to 100 feet
  
• Attached chip to receiver to continue testing
• Tested chip for enabling, disabling, and
  timing
  

12

Design Goals
Computer Engineering

• researched and ordered chip to our
  specifications
  
• coded assembly language
• tested code on evaluation board and software
• tested chip
• made sure program compiled/debugged
• made a pin out board, to solder connections to
• troubleshooting code, connections
• website maintainence

13

Program in-depth

• declare memory address and locations
• pins configured for input/output
• clear interrupts
• set enable state to default
• program will loop to check for interrupts
• set timer for disable state
• clear timer memory locations

14
Flow Chart
15
System Diagram

• M68EM05J1A Emulation Module
• laptop running real-time program
• board is connected to the laptop via com port

16
Chip States
Ground Ringer out Ringer in Disabled Enabled

• Disabled
• gate is closed between signal in and ringer out
• the timer is activated

• Ringer out
• when enabled, outputs a high signal

• Enabled
• the gate is open between the signal in and the
  ringer out

• Ringer in
• (enabled by default) a high is sent to ringer out

17
MC68HC705J1A chip
The MC68HC705J1A is a member of the low-cost,
high-performance M68HC05 Family of 8-bit
microcontroller units (MCUs). All MCUs in the
family use the popular M68HC05 central processor
unit (CPU) and are available with a variety of
subsystems, memory sizes and types, and package
types.
Specifications

• Memory-Mapped Input/Output (I/O) Registers
• 1240 Bytes of EPROM/OTPROM, Including Eight
  Bytes for User Vectors
  
• 64 Bytes of User RAM
• Peripheral Modules
• 15-Stage Multifunction Timer
• 14 Bidirectional Input/Output (I/O)

18
Simulator in-depth

• CPU Window
• shows current values in accumulator, register,
  stack pointer, program counter, condition code
  register, and cycle counter.

• Code Window
• shows actual source code

• Variables Window
• shows current values for specified byte, word, or
  string variables

• Memory Window
• current value of memory locations

• Debug Window
• Error messages appear in the window.

19
Financial Budget, tangible
20
Project Cost, intangible

• 4 Engineers
• x 25 Hours/week
• x 13 Weeks
• x 30.00 hr
• 39,000.00

21
Project Schedule