CET235 / ITE 135 DIGITAL ELECTRONICS DESIGN
Lab 1: DIGITAL NUMBERING SYSTEMS
INTRODUCTION: Digital electronics makes extensive use of various number systems other than base
ten. This lab provides you with practice conversions between binary, octal, hexadecimal, decimal and
Binary Coded Decimal (BCD) number systems.
PARTS NEEDED: None.
PROCEDURE:
1. Complete the chart below by performing the appropriate conversions. Use the “Base Converter” web
page to check your answers.
Octal
37
Hex
Binary
Decimal
BCD
D2
1101011
100
0110 0011
2. Write the binary numbers from 10012 to 101002.
3. Write the octal numbers from 7668 to 10108.
4. Write the hexadecimal numbers from E916 to 10216.
5. Solve the following problems in binary.
a.
10002
+11012
¯¯¯¯¯¯
b.
10112
+01112
¯¯¯¯¯¯
c.
10012
-01102
¯¯¯¯¯¯
d. 101012
-11102
¯¯¯¯¯¯
6. If a digital circuit accepts 5 inputs, how many different input combinations are possible? _____
In general, how many possible input combinations exist for an arbitrary number 'N' inputs? _____
CET235 / ITE 135 DIGITAL ELECTRONICS DESIGN
Lab 2: IDL-800 DIGITAL LAB FAMILIARIZATION
INTRODUCTION: Since the laboratory experiments in this course rely heavily upon use of the digital lab
(trainer), you need to be familiar with its components and of their use. The logic lab you will be using for
this course is a modern, self-contained trainer with numerous built-in features. It includes fixed and
variable DC power supplies, 4-digit digital voltmeter (DVM), signal generator, 8 digital input switches, 2
pulse buttons, 8 LED output indicators, a 2-digit numeric LED display and a solderless breadboard for
circuit prototyping. This lab introduces you to this equipment.
PARTS NEEDED: IDL-800 Digital logic lab (trainer), digital parts kit
PROCEDURE:
Note: The Digital trainer used is relatively new, therefore, the trainer’s familiarization instructions may be
different. The instructor will help explain the trainer used in lab.
PART 1: Equipment and Component Inventory
1. Find the lab equipment bag for your lab station number from the “digital” cabinet. You will be
responsible for using and taking care of the appropriately numbered equipment bag for the entire
course!
2. Use the equipment inventory sheet provided by the instructor to verify that all lab equipment is
present. Sign and date this inventory sheet then return it to the instructor. You will repeat this process
once again at the end of the semester.
3. Use the “parts kit inventory list” found elsewhere in this manual to verify that your parts kit contains all
required components. Be careful not to confuse integrated circuit ID numbers with date codes.
PART 2: Logic Lab Familiarization
4. Verify that your breadboard is blank (nothing plugged in it). NOTE: If you ever notice any wires
broken off in your breadboard, bring it to the instructor's attention -- do not attempt to remove them.
Plug in the digital lab trainer and turn the POWER switch on. For each of the following trainer
components, identify it and perform the related procedure, if given.
5. Removable Breadboard
With the breadboard in front of you, read the following two paragraphs carefully, at least two times.
The breadboard is constructed with four columns (2 each between V1/V3 and V2/V4) of sets of 6
horizontal pins (A-F, G-L). Each of the 28 rows of the horizontal sets (A-F, G-L) are connected in
common. When a component is inserted over one of the 4 vertical channels straddling F/G, the
remaining horizontal holes (A-E, H-L) are available for wiring or test instruments.
These component areas are surrounded above and below by horizontal power busses (black &
red) and these will typically connect to Ground and +5V from the trainer, respectively. NOTE: The red
horizontal strips are not bridged between V1/V2 and V3/V4 across the middle of the breadboard (see
markings). The same is true of the black ground busses between the left and right halves of the
breadboard. You must jumper these if that's what you want (recommended)! Also, there are two 6x30
tiepoint areas at the bottom of the breadboard -- these are simply available for general use.
6. Power Supply
The trainer contains two internal DC regulated power supplies fixed at +5V and -5V as well as two
variable DC regulated power supplies at +0~15V and -0~15V. These power supply outputs are
available on the trainer to the left of the breadboard. NOTE: NEVER allow any of the power supply
outputs to come into contact with each other or with ground (GND)!
7. DVM
Included on the trainer is a 4-digit, 4-range (manual) digital volt meter. The DVM requires connections
to both its + and - inputs. Connect a wire between its - input and GND. Connect a second wire from
its + input to +5V. Switch the DVM's range selector to each of its 200mV, 2V, 20V and 200V positions
and observe the effect on its display. Note that any input voltage exceeding the maximum full scale
input (199.9mV, 1.999V, 19.99V and 199.9V respectively) is simply displayed as a left-justified '1'
which indicates an over-range condition. Repeat this test for each of the trainer's other power outputs
(-5V, +0~15V and -0~15V). Remove both wires when finished.
8. LED Indicators
Above the breadboard area, the trainer includes a 2-digit numeric Light Emitting Diode (LED) display
and eight simple LEDs (0-7). The eight LEDs are used to indicate the logic level of whatever they are
wired to (On = logic high, Off = logic low). Note their numbering (LSB on the right) and that with
nothing connected, these LEDs are internally biased to be off. Connect a single wire from one of the
LEDs first to +5V then move it to GND and note the results on the LED.
9. Logic Switches
To provide input stimulus to your circuits, the trainer provides a number of switch inputs across the
bottom of the trainer. This includes two +5/0/-5V function switches (rarely used), two pulse switches
(A & B), and eight binary data switches (SW0-SW7). The data switches produce a logic HIGH or
LOW output depending on their position. Reconnect the above wire from the LED to one of the data
switches and note the effect on the LED of each of the switch's two positions. The pulse switches
provide both normal (A, B) and inverted ( A, B ) outputs. Move the wire from the data switch first to the
A output (positive logic) and then to the A output (negative logic) and note their effect on the LED.
10. Function Generator
The trainer's built-in signal generator can produce a sine, triangle, or square wave output with both
frequency and amplitude being variable. The sine and triangle outputs are rarely used in this course
but the square wave output is quite commonly used. Set its output for square wave, frequency
timebase to 1, range selector to X1 and amplitude to approximately the 3 o'clock position. Reconnect
the above wire from the LED to the function generator's output. Notice the effect on the LED as you
vary the frequency timebase from 1 to 10. Try switching the range selector above X1 and again notice
the effect on the LED as you vary the frequency. Estimate the maximum frequency at which your eye
can detect pulsating on the LED. ________ Note: the LED does pulsate above this frequency; it's just
that the human eye can no longer detect it! WARNING: Do not connect the function generator directly
to any integrated circuit since its 0 to +/-8V output will permanently damage I.C.s!
PART 3: Wiring Procedure
11. Turn the trainer power off. Install a 74LS04 Hex Inverter in the breadboard. Refer back to step 5 to
insure you are inserting the 74LS04 in a valid location on the breadboard. Using the 7404 pinout in
the appendix of this lab manual, connect Vcc to +5V, and GND to the trainer's GND. Also make the
following wired connections as shown below: inverter #1 output pin 2 to inverter #2 input pin 3, pin 4
to 5, pin 6 to 9, 8 to 11 and pin 10 to 13. Counting Vcc and GND, you will need 7 wires total.
12. For input to this circuit, connect one of the data switches to the first inverter input (pin 1). To visually
monitor the inverter's outputs, connect each of the outputs (pins 2, 4, 6, 8, 10, 12) to an LED (7-2
respectively).
13. Turn the trainer power on. While toggling the data switch, you should notice that each output stage of
the inverter chain will be opposite (inverted) of its input. We will study this logic element in more detail
in the next lab.
14. Turn the trainer power off. Remove all wires and the I.C. using the chip remover tool and return all
components to where they belong.