1 / 90

ECE 372 – Microcomputer Interfacing Laboratory

ECE 372 – Microcomputer Interfacing Laboratory. Pre-labs for ECE 372 Created by Ryan Mattfeld 12/17/12 Last Updated:12/17/12. ORIENTATION. Instructor Information and Syllabus. Instructor Name: Nilim Sarma Email: nsarma@clemson.edu Office Hours: Email to set up appointment.

rufus
Download Presentation

ECE 372 – Microcomputer Interfacing Laboratory

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ECE 372 – Microcomputer Interfacing Laboratory Pre-labs for ECE 372 Created by Ryan Mattfeld 12/17/12 Last Updated:12/17/12

  2. ORIENTATION

  3. Instructor Information and Syllabus • Instructor Name: NilimSarma • Email: nsarma@clemson.edu • Office Hours: Email to set up appointment. • Lab Manual can be found at http://www.clemson.edu/ces/departments/ece/resources/lab_manuals.html

  4. Introduction Objective: • Gain a better understanding of the functionality of a microcontroller. • Learn to interface devices with different modules on a microcontroller. Experiments: 10 experiments involving various modules and a final design project.

  5. Final Design Project • Will combine at least two of the labs performed throughout the semester in a creative way • Worth 30% of final grade • Weekly Lab Reports for reference when making final design • Final lab report will be given on final design project

  6. Equipments • The National Instruments ELVIS system . • Freescale MCU Project Board Student Learning Kit – Prototyping board with microcontroller interface. • Microcontroller - Freescale HCS12 Family, model MC9S12DT256. http://www.clemson.edu/ces/departments/ece/resources/lab_manuals.html

  7. Software Development Environment. CodeWarrior IDE. • Text Editor for writing code. • Cross compiler to generate executables. • Loader program to load the executable on the microcontroller. • Debugger to perform runtime debugging.

  8. Prerequisite • Familiarity with C programming language. • C tutorial available in lab manual.

  9. Freescale Board Connector J1

  10. Mandatory Safety Video

  11. Laboratory 1 – Introduction to the MC9S12DP256B

  12. Laboratory 1 Program • Program will count from 1-16 in binary using LEDs and in decimal using the LCD display. • Download the program from our section on Blackboard under the “information” section • Extract the program to your student (U:) drive • Open the “Lab 1” folder and open the .mpc file to edit the program • Take a few minutes to read the code and figure out what it should do

  13. Laboratory 1 Program • Make sure to turn on both power switches on the NI-ELVIS board and connect the USB cables • Attempt to compile the code (ctrl+F7 is keyboard shortcut) • Identify and fix the error • Hit the “debug” button (green arrow with helicopter) • Run the code and see the result • Modify the code to count backwards

  14. Final Reminders! • Store each lab as a separate file on your student server (copying an old lab folder and renaming it for new labs) • This ensures all necessary files are linked and provides your access to your previous lab code when you begin your final design project. • You can also access your student drive from any computer with internet access at: • https://netstorage.clemson.edu/ • Read over Lab 2 in the lab manual to be prepared for next week!

  15. Laboratory 2 – Reading and Writing Using RAM

  16. Device Memory Map $0000 - $03FF – Registers. $0000 - $0FFF – 4K Bytes EEPROM. $1000 - $3FFF – 12K Bytes RAM. External Memory $FF00 - $FFFF – Vectors. After reset the bottom 1k of the EEPROM ($0000 - $03FF) are hidden by the register space. Refer to MC9S12DT256 Device User Guide.

  17. Laboratory 2 Preparation • Find the folder for Lab 1 that you used last week (stored on your student drive) • Copy the folder and rename it for Lab 2 • Open the .mpc file to edit and compile your code • In main.c, leave the header files and #pragma statement, but delete all code in void main(void) • We will define a command to read and write to the RAM of our microprocessor • ** We will begin writing at reading at memory location ***insert location here***

  18. Laboratory 2 Code • We will create an easy method to access specific RAM memory addresses by using a #define statement • #define _P(ADDRESS) *(unsigned char volatile *)(ADDRESS) • This command will allow you to both read and write to a specific address in RAM. • Conceptually, in your program, you can use • _P(**desired memory address**) • Like you would use a variable to store and use information.

  19. Laboratory 2 Code • Program goal: Write **** insert phrase here **** to RAM, then read from RAM to the LCD • At the beginning of your program, make sure you initialize the LCD using “LCDInit()” • Then, make sure that after every 8 characters you clear the LCD using “LCDClearDisplay()” • You can write to the LCD using the command “LCDPutChar()” • Use loops to write the phrase • Use conditional statement to clear display

  20. Preparations for Next Week • Before next lab, read over Lab 3 in your lab manual, Application of a Digital Latch.

  21. Laboratory 3 – Application of a Digital Latch

  22. Lab 3 Preparation • Find the folder for Lab 2 that you used last week (stored on your student drive) • Copy the folder and rename it for Lab 3 • Open the .mpc file to edit and compile your code • This lab combines hardware with software • Uses 74LS374 Flip-Flop chip (D Flip-Flop)

  23. 74LS374 – D Flip Flop • Latch data from Input Pin to Output Pin when there is a rising edge on Clock Pin.

  24. Laboratory 3 - Hardware Prep • The Input, 1D corresponds to the output, 1Q. Reference chip diagram: • Input: Switches (SW1 1 and SW1 2) • Output: LEDs (LED 1 and 2) • Intermediate Output (Port B LEDs) (Port B is hardwired to 4 LEDs) • Wire SW1 1 to 1D, SW1 2 to 2D • Wire 1Q to LED 1, 2Q to LED 2

  25. Laboratory 3 – Microcontroller Comm. • Must wire inputs to microcontroller to manipulate input with code. • Wire SW 1 to PTT 0 (reference page 50 in lab manual for Port wiring table) • Wire SW 2 to PTT 1 • Clock Pulse Input: Pushbutton (PB1) to Port M 1 • Clock Pulse Output: Port M 0 to clock of Flip-Flop • Wiring complete!

  26. Laboratory 3 – Software Prep • To use input and output registers on the microcontroller, must designate them for input or output in code. • DDR – Data Direction Register (0 for input, 1 for output) • Will use Port T, channels 0 and 1 for input, so we will set DDRT = 0x00; • Will use LEDs hard wired to Port B for output. • LEDs wired to Port B channels 4-7, set DDRB=0xF0; • Will use Port M channel 0 as input and Port M channel 1 as output, set DDRM = 0x01

  27. Laboratory 3 – Main Function • Constantly loop, looking for switch input. Port T 0 and Port T 1 will change between 00, 01, 10, 11 based on switch configuration. • For each possible state of Port T, light corresponding LEDs (set Port B to appropriate values) (HINT: Port B 4-7 are wired to LOW active LEDs) • Finally, must generate clock pulse for D Flip-Flop • Check if Port M channel 1 is 0 (Push Buttons are low active). If it is, generate clock pulse on Port M channel 0. (Set PTM = 0x01 then reset it to 0x00)

  28. Result • When complete, should have two displays: • 1) When you flip one of the switches, the LEDs hard wired to Port B should immediately change • 2) When you push Pushbutton 1, the switch values will travel through the Flip-Flop, and light the LEDs you wired your outputs to.

  29. Flowchart

  30. Preparations for Next Week • Before next lab, read over Lab 5 in your lab manual, Keypad Interfacing

  31. Laboratory 5 – Keypad Interfacing

  32. Laboratory 5 Hardware Prep • Plug in Keypads with brass side of connector facing left • Keypad 1  Port T 1 • Keypad 2  Port T 2 • Keypad 3  Port T 5 • Keypad 4  Port T 3 • Keypad 5  Port T 6 • Keypad 6  Port T 7 • Keypad 7  Port T 4 • Keypad 8  Port T 0

  33. Keypad Description/Operation

  34. Laboratory 5 software prep • Set Port T channels 0-3 as output and channels 4-7 as input using DDRT • New registers: PERx (Pull Enable Register) and PPSx(Polarity select Register) • PER and PPS work together to pull desired ports either high or low. • Pull Port T channels 4-7 high. • Enable Port T channels 4-7 for pulling(PERT = 0xF0) • Pull Port T channels 4-7 high (PPST = 0x00) (setting PPST to 0 pulls corresponding channel high)

  35. Laboratory 5 Software Tools • Arrays can make keyboard interfacing easier: • unsigned char mask[16]={0xEE,0xDE,0xBE,0x7E, 0xED,0xDD,0xBD,0x7D, 0xEB,0xDB,0xBB,0x7B, 0xE7,0xD7,0xB7,0x77}; • unsigned char key[16]={'D','1','2','3', 'A','4','5','6', 'B','7','8','9', 'C','*','0','#'};

  36. Laboratory 5 Code Flow Chart START INITIALIZE PORT T INITIALIZE (proper header files, declarations, and definition) No DETERMINE IF A SPECIFIED COLUMN IS ACTIVE IN THE ACTIVE ROW TURN ON 1 ROW AT A TIME Yes SEND THE PRESSED KEY TO THE LCD DISPLAY

  37. Preparations for Next Week • Before next lab, read over Lab 4 in your lab manual, Interrupts

  38. Laboratory 4 – Interrupts

  39. Laboratory 4 Wiring Diagram +5V Port P 0 Port P 1 Gnd

  40. Laboratory 4 Software Prep • INPUTS • Port P 0 and 1 should be used as interrupts • Port P generates interrupt vector 56 (reference lab manual page 51 for vector interrupt table) • Registers: • DDRP = 0x00; (interrupts are inputs) • PERP = 0x03; (Enable pulling for interrupt channels) • PPSP = 0x03; (Pull low so high active button will trip interrupt) • PIEP (Port Interrupt Enable Register) = 0x03; (This enables Port P 0 and 1 as interrupts)

  41. Laboratory 4 Software Prep • OUTPUTS • LEDs hard wired to Port B will be outputs • DDRB = 0xF0; (Channels 4-7 are wired to the LEDs so they should be outputs) • LCD will constantly count from 0-9 • LCDInit(); • LCDClearDisplay();

  42. Laboratory 4 Software Prep • LOGIC • Constantly loop to count from 0-9 on the LCD display • Create interrupt function (using interrupt 56, the interrupt vector corresponding to Port P) • Check PIFP to see which interrupt was triggered • Light LEDs to reflect which interrupt was triggered • Reset Port P flags by setting the PIF(Port Interrupt Flag) register to a 1 for each channel you want to reset

  43. Laboratory 4 Code Flow Chart

  44. Preparations for Next Week • Before next lab, read over Lab 7 in your lab manual, Rotary Pulse Generator

  45. Laboratory 7 – Rotary Pulse Generator

  46. Laboratory 7 Wiring Diagram Rotary Pulse Generator Port P 0 Port J 7

  47. Laboratory 7 Software Prep • INPUT • Port P 0 and Port J 7 are interrupts wired to Output A and Output B • Rotate Right Increase position • Rotate Left Decrease position • Change in voltage produces interrupt • Can determine which direction Rotary Pulse Generator turns based on interrupt and state of Port P 0, Port J 7

  48. Laboratory 7 Software Prep • INPUT • Interrupt Vector for Port P • Interrupt Vector for Port J • Two interrupt functions • Set Port P 0 and Port J 7 as inputs • Set PERP and PERJ to enable Port P 0 and Port J 7 for pulling

  49. Laboratory 7 Software Prep • OUTPUT • Port B LEDs will be used to show rotation in rotary pulse generator • Set Port B 4-7 as output • Initialize Port B LEDs off (Low Active)

  50. Laboratory 7 Software Prep • LOGIC • Pulling registers high and low is essential • Interrupt trigger requires voltage change • As pulse generator rotates, voltage changes from low to high and high to low. • Pull high if next voltage change is high  low • Pull low if next voltage change is low  high

More Related