Introduction to Interfacing Projects

Nareen Khan

Using Turing

Command to send data to parallel port

parallelput (x : int) The command sends 1 byte of data to the

parallel port at a time. Using 1 byte (8 bits) we can represent

28=256 different states. The 8 bits are sent along the Data pins on the

parallel port (Pins 2-9, D0-D7)

19 8 67 5 4 3 213 12 11 10

22 21 1920 18 17 16 1525 24 23 14

Understanding the Parallel Port

D7 D6 D4D5 D3 D2 D1 D0

Data Lines (D) used for output.

Grounds

Status Lines (S) used for input.

Control Lines (C) may be used for input / output

Binary on the Parallel Port

parallelput(0) parallelput(1) parallelput(37) parallelput(255)

0 0 00 0 0 0 00 0 00 0 0 0 10 0 01 0 1 0 11 1 11 1 1 1 1

The integer parameter is translated into binary and each bit corresponds to one of the data pins on the parallel port.

Unsure of your conversions? Try this utility.

What does the circuit look like?

parallelput(0)

Switch is open, no path, LED off

parallelput(1)

Switch is closed, path exists, LED on

Voltage from

parallel port

220Ω

Pin 2

Pin 18

Breadboard Basics

Connected vertically in blocks of 5

Connected horizontally

Light Emitting Diodes

LED’s will only work if they are installed in the right direction.

Here are three ways to tell which is the negative (-’ve) lead.

1) –’ve lead is shorter

Light Emitting Diodes

LED’s will only work if they are installed in the right direction.

Here are three ways to tell which is the negative (-’ve) lead.

2) Internal segment is

larger

Light Emitting Diodes

LED’s will only work if they are installed in the right direction.

Here are three ways to tell which is the negative (-’ve) lead.

3) Flat side on lip

Top View

Wiring an LED

+’ve, Long Lead

Project Samples

Traffic Intersection

Traffic Intersection

Traffic Intersection

Student GUIs

Student GUI’s

The Traffic Intersection Project

Steps:

1) Wire six LED / resistor pairs on breadboard

2) Attach the wires to your model

3) Write your program

4) Enjoy hours of staring at the lights change

Step 1 – Wiring the lights

+’ve, Long Lead

-’ve, Short Lead

Step 2 – The D-Sub Connector

1)Attach your wires to the crimp pins.

2)Be sure to press the clamps down tight on the wire.

3)Push the crimped pin into the D-Sub Connector (it’s a tight fit).

4)Repeat for the other 7 wires.

Step 1 – Wiring the lights

Step 1 – Wiring the lights

Test your interface

Once you’ve got the wires connected to the parallelport, you can test the interface.

Try :

parallelput(255)

This should turn on all your lights.

Sample Program #1

Sample Program #Step 1 – Wire Wrapping

Make Use of the Tri-State Buffer – See the Handout

Making The Turing Program 1

Make a Program Header%

% The "trafficIntersection" program

% Course Code: ICS 3M1

% Instructor: Your Teacher

% Date: April 25, 2007

% Initial Release

%

% This Program simulates a traffic intersection in graphics. It can also properly drive the actual

% intersection by use of a parallel port and binary outputs.

Making The Turing Program 2

Create a User Defined Data Typetype trafficState: % data type trafficState will store various components of traffic

states.

record

timeWait : int % var for the time in that state

binState : int % binary value of that state (more details see pin output state table

NSPic : string % var for the state of the NS light

EWPic : string % var for the state of the EW light

end record

Making The Turing Program 3

Create a User Defined Data Typedrawfillbox(0, 0, maxx, maxy, 54) % code for background colour% The 6 states are declared as an array of trafficState data typevar trafficPattern : array 1 .. 6 of trafficState

% Below contains the value of each of the states% timeWait: Green light - 5 sec.% Yellow light - 2 sec.% Both red light - 1.25 sec.% binaryStates in decimal: NS green - 1 % NS yellow - 2% NS red - 4% EW green - 8% EW yellow - 16% EW red - 32

Making The Turing Program 4

Note the binary States listed belowdrawfillbox(0, 0, maxx, maxy, 54) % code for background colour% The 6 states are declared as an array of trafficState data typevar trafficPattern : array 1 .. 6 of trafficState

% Below contains the value of each of the states% timeWait: Green light - 5 sec.% Yellow light - 2 sec.% Both red light - 1.25 sec.% binaryStates in decimal: NS green - 1 % NS yellow - 2% NS red - 4% EW green - 8% EW yellow - 16% EW red - 32

Making The Turing Program 5

Then Define Each Traffic Pattern in this manner…

%NS Green EW Red

trafficPattern(1).timeWait := 5000

trafficPattern(1).binState := 1 + 32

trafficPattern(1).NSPic := "trafficgreen.bmp"

trafficPattern(1).EWPic := "trafficred.bmp“

%NS Yellow EW Red

trafficPattern(2).timeWait := 2000

trafficPattern(2).binState := 2 + 32

trafficPattern(2).NSPic := "trafficyellow.bmp"

trafficPattern(2).EWPic := "trafficred.bmp“ etc…

Making The Turing Program 6

Create a Procedure% procedure for loading the pictures in the different states

procedure drawIntersection (NSFile : string, EWFile : string)

Pic.ScreenLoad (NSFile, 250, 250, 0)

Pic.ScreenLoad (EWFile, 100, 150, 2)

Pic.ScreenLoad (NSFile, 250, 50, 0)

Pic.ScreenLoad (EWFile, 400, 150, 2)

end drawIntersection

Making The Turing Program 7

Finally, cycle through the lights…% Loop to make the cycle continuous

for i : 1 .. 4

% Loop for each of the traffic states and giving drawIntersection the images to change

for j : 1 .. 6

drawIntersection (trafficPattern(j).NSPic , trafficPattern(j).EWPic)

parallelput (trafficPattern(j).binState) % send info to parallel port

delay (trafficPattern(j).timeWait) % delay the amount of milliseconds indicated in traffic state

end for

end for

Making The Turing Program 8

Make Sure You Have These Graphics Files