2. ECET 340 Week 1 HomeWork 1
For more course tutorials visit
www.newtonhelp.com
1. Give three examples each of internal and external peripheral devices
as referenced to the HCS12 microcontroller and not an entire PC. (2
points)
2. Given “the requirements of each signal’s destination must match the
capabilities of the signal’s source,” name some of the electrical signal
parameters that must be considered when designing an interface between
two different hardware components. (2 points)
3. Write down the instructions needed to program PORT A for pins
PA7, PA4-PA0 as inputs and PA6-PA5 as outputs. Answer should be a
valid C language statement. (2 points)
4. Write an instruction sequence to output the value $35 to PORT P. Use
the C language only when writing your answer; - no assembly language.
(2 points)
5. Write an instruction sequence to configure Port H for input, read in
the current signal levels on the Port H pins, and store the value to a C
variable called data1. Use the C language only when writing your
answer, no assembly language. Also make sure to set the data direction
register appropriately in your answer. (2 points)
3. 6. Write a short program in C language which reads in the bits on port H,
inverts the bits and adds 1 to the result, and then outputs the result onto
port P. Be sure to include port initializations and variable declarations in
your code. (2 points)
7. Using only Ports B, H, & J, (see Figure 1} write C code to read in the
value from dip switch 1 (SW1) {all 8 bits}, invert the bits, and then
display the results on the 8 LEDs driven by Port B (see Figure 3). When
the value is a ‘1’, the LED is ON, and when it is a ‘0’, the LED is off.
See how SW1 is connected to Port H (see Figure 2), and how the LEDs
are connected to Port J (see Figure 3) (2 points)
8. What maximum current will be drawn from the 5V output of a
peripheral device connected to an HCS12 input port? What input
resistance does this represent? Please note the problem states connected
to an HCS12 “input port”. (3 points)
9. Given an LED with a forward drop of 1.5V and an operating current
of 10 mA, design the interface to the HCS12 showing your calculations.
(3 points)
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 1 iLab 1
For more course tutorials visit
www.newtonhelp.com
4. OBJECTIVES:
To become familiar with Microcontroller MC9S12 parallel ports and
how simple input and output devices are interfaced through them.
To learn how to program I/O instructions in C language.
To learn how to organize a program to read data from input ports,
process the data, and display the result on a simple output device.
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 1 iLab LCDs and Keypad (100 Score)
For more course tutorials visit
www.newtonhelp.com
Laboratory Title: LCDs and Keypad
Objectives:
1. To become familiar with LCD initialization
2. Displaying messages on the LCD
5. 3. Developing a poll routine to capture Keypad information
4. Combine the LCD and Keypad programs
1. What distinguishes a control data value from a character data value
for the LCD module?
2. Describe the steps in the keypad polling routine.
3. Draw a flow chart for the keypad LCD software code.
4. Discuss challenges experienced in developing the keypad LCD
software code.
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 2 HomeWork 2
For more course tutorials visit
www.newtonhelp.com
1. Where does program control transfer to when an interrupt occurs? +2
points
2. Which one of the following Interrupts has highest priority? +2 points
3. RAM Vector table addresses $3E52 belongs to which interrupt? +2
points
6. 4. Before exiting an ISR, the programmer should use which command?
+2 points
5. In which one of the following sequences is the stack pulled by rti? +3
points
6. Given the starting address for the TC0 Interrupt is to become $5000.
Write the assembly instruction necessary to place this ISR address into
the interrupt vector table and then unmask the interrupt (assembly only).
+3 points
7. Write the C statements needed to place the address of an interrupt
service routine that is to be called PortJ_handler into the vector address
for the Port J interrupt and then unmask the interrupt. +3 points
8. Circle the interrupt below that will have highest priority after the
statement ;is executed. +3 points
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 2 iLab 2
For more course tutorials visit
www.newtonhelp.com
ECET 340 Week 2 iLab 2
----------------------------------------------------------------------------------------------------------------------
7. ECET 340 Week 2 iLab Interrupts in C (100 Score)
For more course tutorials visit
www.newtonhelp.com
Objectives:
1.To become familiar with the configuring and enabling of interrupts
2.Using the external interrupt
3.Using the Real Time Interrupt
4.To combine two interrupts within a program
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 3 HomeWork 3
For more course tutorials visit
www.newtonhelp.com
1. Sketch a circuit that can be used to debounce a pushbutton and
explain how it works. (4 points max)
8. 2. In Figure 7.32 on page 339 of the Huang textbook, if the row has and
the columnsare , which key is pressed? (2 points max)
3. In Figure 7.32 on page 339 of the Huang textbook, explain why the
10kΩ resistors ties to VCC are required. (2 points max)
4. Write down the lines of C code (interrupt service routine, ISR) that
generates an interrupt when Port H pin 0 becomes a logic “1”. Within
this ISR, disable interrupts, clear the interrupt flag, then enable
interrupts, and return from routine. I also want the routine or lines of C
code that initialize Port H pin 0 to be used as an interrupt (hint: think
data direction register) (2 points max)
5. Write down the C statements you would need to add to the main
program of the keypad driver program given in lecture and lab in order
to store the key characters to a buffer area of memory called
keys_entered and exit the program as soon as either seven keypresses are
entered or the the “D” key is entered. (Counts as two questions) (4
points max….you need to use arrays in C code)
6. State the functions of pins RS, E and R/W in the LCD. (4 points max)
7. Give the state of RS, E and R/W~, and the command code (in hex) for
the 20th location, line 2 on the 40x2 LCD described in lecture. (2 points
max)
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 3 iLab 3
For more course tutorials visit
9. www.newtonhelp.com
SOLVED ECET 340 iLAB3
OBJECTIVES:
To learn the basic operation of a keypad.
To understand how to interface a keypad to a microprocessor.
To learn how to program a keypad driver in C language.
To learn how to program a keypad activated interrupt that identifies the
key being pressed and displays or otherwise returns its value to the main
program.
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 3 iLab Timers in C (100 Score)
For more course tutorials visit
www.newtonhelp.com
Objectives:
1.To become familiar with the configuring and enabling of timers
2.Using the timer counter
3.Using the input capture timer
10. ----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 4 HomeWork 4
For more course tutorials visit
www.newtonhelp.com
1. Determine the conversion time for an ADC0804 (8-bit), where 66
clocks per bit are required, if its clock frequency is 50 kHz.
2. If an 8-bit SAR has Vref = 10 V, what is the binary value for an input
voltage of 7.28 V?
3. What is the percent error for the binary answer found in Problem #2?
4. Given an 24 MHz bus speed. Write down the line(s) of instruction
which set the ATD1 unit for 2MHz conversion frequency, 10-bit
resolution and 8 A-to-D clocks per sample time.
5. A single 10-bit, left justified conversion of 3.75V is complete in
ATD0. Assume and
i. Name the register(s) where the result of the conversion is found
11. ii. What are the values in each of the 16-bits of this register after
conversion is complete? Assume the result is unsigned. Show work
6. Assume that a position-sensitive potentiometer can measure up to 25
cm over a voltage range of 0 to 5 V. If an 8-bit ADC outputs a value of
0111 1010, what is the distance measured?
7. Design the basic interface circuit (using an op amp) for a temperature
sensor that covers a range of 0° to 70°C if the output of the sensor is 2
mV/1°C and the ADC voltage range is 0 to 4 V.
8. Design an amplifier suitable for converting the output voltage from an
LM35 temperature sensor (10 mV/°C) into a signal that makes use of the
full input voltage range (0-5V) of the HCS12 ADC port pins. Assume
the LM35 is to measure temperatures from 0°C up to +150°C. Show
work and circuit!
9. Given a sensor with W that outputs voltage in the range +1.25V to
+4.25V. Show the complete interface circuitry needed to connect it to
the A/D unit built-in to the HC12 Controller.
10. Write the lines of C code needed to configure the A/D converter,
start the conversion, and output a hex integer in the range 0x0000 to
0xFFFF to the variable called data1 that is proportional to airflow input
(0.0 to 1.0 litre/min). No further conversion is required
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 4 iLab 4
12. For more course tutorials visit
www.newtonhelp.com
I. OBJECTIVES:
To learn how to use A-to-D converters to digitize signals from analog
input devices.
To learn how to write a C language program that samples the data from
an analog device, digitizes it and formats it for output on an LCD.
To become more proficient in programming displays for real-time
operation.
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 4 iLabEvent Counter and DACs in C (100
Score)
For more course tutorials visit
www.newtonhelp.com
Objectives:
13. 1.Become familiar with the configuring and enabling of the event
counter.
2.Use the digital-to-analog converter to produce signals.
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 5 HomeWork 5
For more course tutorials visit
www.newtonhelp.com
1. Explain, briefly, why an analog restoring filter is sometimes used at
the output of a DAC.
2. Given Iref = 2 mA for a DAC1408 IC, find Iout for the input 1110
1110
3. Find the number of discrete voltages output by a 12-bit DAC. Show
work.
4. Use the internet to locate the data sheet for an MC1408 DAC. From it
find, for the MC1408-7 version, the following:
a. The settling time
b. Accuracy at full scale output current (1.99 mA), 25ºC
14. c. Output current range when -7V <vee="">< -15v="" is="" used.="">
5. Assume that an MC1408 DAC is attached to Port T of an HC12
Microprocessor as shown below. Verify that the program below outputs
8 different values to the DAC and determine the output voltage (Vout)
after each output operation. Show your work in the space below
6. How does the SCI system achieve synchronization between the
transmitter and receiver?
7. The SCI1 serial port is initialized for 8 data bits, 1 stop bit and 2400
baud. How much time is required to data transfer 3000 characters?
8. Why is the maximum data rate of the SPI system faster than the SCI
system?
9. Discuss the advantages and disadvantages of the SCI versus SPI data
transfers.
10. Provide the C language code to set the SPI to the lowest frequency.
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 5 iLab 5
For more course tutorials visit
15. www.newtonhelp.com
Scenario/Summary
This week's lab covers two areas, conversion of digital HCS12
signals to an analog format, and the use of a Serial Peripheral Interface
(SPI)
to transfer data, and commands between the HCS12, and the DAC
peripheral.
Deliverables
For this lab, the deliverables include the cover sheet,
filled-in sections of the lab report, photographs (online), or instructor
sign-offs (onsite), and answers to the questions. The cover sheet must be
completed in typed format.
L A B S T E P S
STEP 1: Download the
Lab
Download Lab 5 located in DocSharing and save it to your PC.
STEP 2: Predict the Results of Waveform
Generation Program
16. Study the 340_lab5_1 program and predict the performance, and
outputs of the code. Answer the questions in Part A, Step 2.
STEP 3: Run the Waveform Generation
Program
Use the 340_lab5_1 program to load the Dragon12 board and verify
the operation. Photograph your circuit with an oscilloscope attached
(online),
or obtain your instructor's sign-off (onsite).
STEP 4: Design Project
Modify the software to produce, either a square wave, or
sawtooth wave based on user input. Photograph your circuit with an
oscilloscope
attached to show both waveforms (online), or obtain your instructor's
sign-off
(onsite).
STEP 5: Answer the Questions
There are two questions that must be answered in this lab.
STEP 6: Complete the Cover
17. Sheet
Type the required information onto the cover sheet.
STEP 7: Submit Your Deliverables
See Syllabus/Due Dates for Assignments & Exams for due date
information.
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 5 iLab Analog to Digital Conversion in C (100
Score)
For more course tutorials visit
www.newtonhelp.com
Objectives:
1.To become familiar with the configuring and enabling of the analog-
to-digital converter
2.Usage of both the ATD and RTI interrupt service routines
----------------------------------------------------------------------------------------------------------------------
18. ECET 340 Week 6 HomeWork 6
For more course tutorials visit
www.newtonhelp.com
1. What are the four main functions of the HC12 Timer unit?
2. Two input capture events occur at counts 0x1037 and 0xFF20 of the
free-running counter. How many counts (in decimal) have transpired
between these two events?
3. What is the maximum time possible before the free-running counter
overflows when the e MHz?
4. Two input capture events occur at 0x1037 and 0x002A. If the
prescaler bits PR[2:1:0] are set to 101 and the e clock is 24 MHz, how
much time as transpired between the two events?
5. Calculate the count that should appear in the timer capture register
TC0 if a 125 kHz rectangular wave is inputted on timer pin PT0 while
TCTL4 is preset for falling edge detection. Assume a 24 MHz e-clock,
TMSK2 was programmed with the value $02, and the count of the 1st
edge event has already been subtracted off from TC0.
19. 6. Write down the name of the HC12 timer register that should be polled
through software to determine whether or not an active input edge has
been captured on one of the port T pins.
7. What is the duty cycle of a signal produced by the PWM when and ?
a. 28.0% b. 29.8% c. 50.0% d. 72.0%
8. What values are required for period and duty cycle to generate a 6.0
kHz, 95% duty cycle waveform using the PWM function? Assume e-
clock frequency is 24 MHz.
9. What is the slowest clock signal that can be generated from the PWM
output using the 16-bit counter mode with pre-scaling and scaling?
Assume e-clock frequency is 24 MHz.
10. Write down the C statements needed to program PWM channel 0 to
output a 12.5 kHz left-aligned wave with 30% duty cycle. Assume e-
clock frequency is 24 MHz.
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 6 iLab 6
For more course tutorials visit
www.newtonhelp.com
20. ECET 340 Week 6 iLab 6
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 6 iLab Asynchronous Serial Communications
in C (100 Score)
For more course tutorials visit
www.newtonhelp.com
Objectives:
1. To become familiar with the configuring and enabling of serial
communication transmitter
2. To configure the microcontroller to receive serial communications
from another device
1
What commands are utilized for the configuration of the asynchronous
serial communications transmitter? How does each affect the operation
of the transmitter?
2
21. What is being used to configure the setup and control of the
asynchronous serial communications receiver?
3. Describe a technique that can be used to configure the software to
manage both the transmitter and receiver?
4. Discuss challenges experienced in working on the lab project.
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 7 HomeWork 7
For more course tutorials visit
www.newtonhelp.com
1. The movable part of the solenoid is the: +2 points
2. Why is the 6N139 optoisolator used in the interfaces to devices such
as large motors? +2 points
3. Calculate the number of steps per revolution for a stepper motor with
a step angle of 7.5°. +2 points
4. How is stepper motor speed controlled? State any two ways a program
can do this. +2 points
5. For this problem, you should look at Figure 5A on the next page as a
physical example of a stepper motor. It is an example of a stepper motor
with four (4) magnetic windings which are connected via an interface
circuit to the HCS12 Port T pins 4, 5, 6, & 7, with an armature (rotor)
22. that has 12 poles (combined number of North and South magnetic
poles). Notice how each step rotates the rotor 30 degrees, and notice the
logic states on the Port T pins going from Step 1 to Step 2. To rotate the
rotor 90 degrees, you would need three (3) steps (see figure 5A for
explanation).
6. Identify 2 major kinds of devices that can be used to interface a dc
motor to the HCS12. +2 points
7. Given that pulses need to be delivered to a specific dc motor at the
rate of 12.5 kHz to avoid vibration, write down the C statements needed
to output pulses from the HCS12 to drive the at 80% of its full drive
level. +2 points
8. An HCS12 timer input capture/output compare register (TC0) holds
the value 0x498 when timing the period between pulses coming in from
a servomotor’s optical encoder (see Figure 8A below for setup of optical
encoder). Assume the counter/timer is operating at 1.0us. The encoder
wheel has 6 holes. Find the motor’s speed in RPM. Show work. +2
points
9. Unidirectional dc motors often have high-voltage diode connected for
reverse-bias across the motor’s input terminals. Explain why this is
done. +2 points
10. What advantages do dc motors offer over stepper motors? +2 points
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 7 iLab 7
23. For more course tutorials visit
www.newtonhelp.com
ECET 340 Week 7 iLab 7
----------------------------------------------------------------------------------------------------------------------
ECET 340 Week 7 iLab HVAC Automatic Temperature
Controller (100 Score)
For more course tutorials visit
www.newtonhelp.com
Title: HVAC Controller
I. OBJECTIVES
1.To become familiar with the thermistor
2.To use integrated modular programming techniques in developing the
project
3.To write a report document for the HVAC Controller
----------------------------------------------------------------------------------------------------------------------
