Word Generator in Multisim - 7 Segment Counter

Using the Word Generator for 7 Segment Counter Circuit

Date: 2/28/2022

Authors: Bits4Bots Team

We have designed simple 4 bit counter circuits using dip switches and ones using BCD to 7-segment decoder IC's. Here we use the Word Generator instrument in Multisim to send digital words or (bit patterns) into the digital circuit. 

• Start by placing the Word Generator instrument onto the workspace. Locate this component on the right panel 0101 icon.
• Next add at least one (1) 7 segment cathode display (any color)
• Add at BCD to 7 Segment decoder. We used the 4511BP_5V

Power and ground the circuit according to the IC pinouts. See image. 

Wire the circuit by connecting the segments A-G to the decoder. The output pins (0-7) on the Word Generator are used to connect the BCD of the 4511BP chip. The enable (EN) - (~LE in Multisim)  pin is grounded. The LT and BI pins are connected to power. 

Double click the Word Generator component to configure the settings. 

Recommended settings:

1. Frequency: 60Hz
2. Controls: Cycle
3. Display: Binary
4. Trigger: Internal

Click the "set" tab to configure the following

1.  Preset Pattern: Up Counter *starting at zero (0)
2. Display Type: Hex
3. Buffer Size: 0400 by default
4. Output Voltage Level: 4.5V - High and 500mV - Low by default
   

Now run the simulation by clicking the green icon in the Multisim ribbon.

Further learning: Try adding a switch to control the trigger externally. Also add a second 7 segment display and cascade it to count up to 6 bits (63). If you are really into electronics how about adding three (3) 7 segment displays and counting up to 8 bits (255).

🖰 Drag and drop the snippet below and simulate it on your own.

If you enjoyed this project follow us here and on Instagram.

References: 

1. https://www.digikey.com/en/maker/projects/how-to-interface-a-seven-segment-display-with-an-arduino/9c05f147618c4fe3b8bb79acce5c60e3
2. https://zone.ni.com/reference/en-XX/help/375482B-01/multisim/wordgenerator/#:~:text=Multisim%2014.2%20Help,word%20generator%20to%20the%20circuit.
   
3. https://images.slideplayer.com/19/5767463/slides/slide_22.jpg
   

PIC Driven LCD Display 20x4 Multisim

Demo of how the PIC16F84A MCU controls the LCD display

Date 2/19/2022

Author: Bits4Bots Team

A simulation of a PIC16F84A that controls a scrolling “Bits4Bits” text on a LCD display. The text shifts from left to right until the MCLR pin is grounded in the software by pressing the "spacebar" on the keyboard.

• The PIC reads an 8-bit character from its internal EEPROM. 

• The text data must be loaded beforehand by loading an external file named Bits4Bots.mch

• The PIC then sends instructions to the LCD display component to control the text being displayed.

Function: PIC mid-range 8 Bit Microcontroller

Assembly language is used to program the PIC. Right click the IC in the Multisim workspace to view the code. 

The source code view shows the assembly or C source code for the MCU program.

If you are building this circuit, set the MCLR pin to VCC (high). The Master Clear pin is an optional external reset that is activated by pulling the pin low. During normal operation, it needs to be pulled high typically through a resistor to VCC.

Along with its selection of MCUs, Multisim contains a number of peripheral devices.

The MCU Group contains RAM and ROM devices that are designed to function specifically with the MCUs.

Watch us modify this Multisim MCU LCD Display on YouTube. 
Tell us what sample file you would like to see in our next blog.

To help you with your personal text message consider visiting https://www.rapidtables.com/convert/number/ascii-to-hex.html to quickly convert ASCII to Hex. Save the file in Notepad software with the extension .mch *Try saving different messages to load into the LCDDisplay sample .ms14 file. In our demo we used a message that says 

Bits4Bots 🠊  42 69 74 73 34 42 6F 74 73, 

Subscribe 🠊53 75 62 73 63 72 69 62 65 , and 

Follow us on Instagram 🠊 46 6F 6C 6C 6F 77 20 75 73 20 6F 6E 20 49 6E 73 74 61 67 72 61 6D . 

The MCP Memory view is where the Hex code can be changed manually. The main focus for quickly changing the original code is the EEPROM. It stands for electrically erasable programmable read-only memory and is a type of non-volatile memory.

Just double click in the Hex box to create a new message. It can be saved as new .mch file or a file can be imported as well as cleared from the memory.

The contents of the MCU Memory View change depending on the type of MCU. It may, for example, contain internal memory information, register views and configuration information.

👈 Drag and drop this snippet to your Multisim workspace to practice.

To learn more visit the links below.

Reference material: 

1. https://zone.ni.com/reference/en-XX/help/375482B-01/multisim/mcututorial/
2. https://www.ni.com/pdf/manuals/374486a.pdf
   

LabVIEW Multisim API Toolkit - RLC Values Example

Automate your Multisim design in LabVIEW 

Written by: Larsha Johnson

Date: October 24th, 2021

If you like designing electronic circuits in Multisim and would like to automate the simulation and analyses in LabVIEW, this example will walk you through how it can be done. The link below may help with missing NI module, Toolkit, or driver warning when opening VI errors.

Multisim Toolkit with LabView

The Multisim Automation API and the LabVIEW Multisim API Toolkit (which uses the API) recognize and can be used to control the values of all circuit parameters in the design. This lets you control most component parameters from the API.

This example uses Multisim version 14.2 and LabVIEW 2021

First open Multisim file RLC values from the blue sample folder → LabView Multisim API Toolkit.

After the file is loaded into Multisim workspace, open LabVIEW, click the "File" tab and open the RLC Values vi as shown.

The simulation should run from here if all the necessary NI Modules, toolkits, and drivers are installed correctly. However, we will explore further by clicking the "Windows" tab and opening the associated block diagram. *The original design was modified by removing the blocks section "Multisim preparation" and replaced with a single "Select File Path" block form the Multisim Add-on tab. 

💬This may differ depending on software version.

If any errors should occur, in this diagram by block location is where they will be listed. From the LabVIEW front panel or from the block diagram, press the white arrow icon to run the simulation on the Multisim RLC Values circuit. 

This demonstrates how to sweep a resistor value to calculate a phase shift plot. (set to R2 by default)

In Multisim alternative analyses and simulations can be performed such as "Parameter Sweep", "Transfer Function", and "Pole Zero" to name a few.

🤔 Enjoyed this blog? Learned something useful? Consider following us for more content.

If you have errors visit this link: NI LABS TOOLKITS or comment if you find solutions to help others.

https://www.ieee.li/pdf/viewgraphs/circuit_design_simulation_and_virtual_instrumentation.pdf

Traffic Light in NI Multisim using Programmable Logic Devices (PLD)

Traffic Light in Multisim using PLC

Written by Larsha Johnson
9/27/2021

Programmable Logic Devices (PLDs) are integrated circuits that contain a relatively small number of functional elements that provide user-configurable logic functions (AND, OR, etc.)
In Multisim a PLD schematic contains specialized components that define the operation of the individual logic blocks of the PLD.

What is PLC and PLD?

The biggest difference between the two is the control logic. PLC is a fixed logic device (the function is realized by changing the software), and PLD is a variable logic device (the function is realized by changing the internal circuit structure). 

The concepts of PLC and PLD can be practiced through this two-way traffic light example. The main implementation of traffic light signals in to avoid traffic jams and serves the purpose of avoiding vehicular collisions.

The ladder diagram in this blog runs two traffic lights. The ladder diagram is contained in a separate hierarchical block called TrafficLightLogic

There are two different traffic light examples available, look in the sample circuit "blue folder icon" in the Educational version of Multisim that implements a traffic light:

1. National Instruments\Circuit Design Suite 14.2\samples\Educational Sample Circuits\Ladder Diagrams
2. National Instruments\Circuit Design Suite 14.2\samples\PLD Sample Circuits

The first choice uses programmable ladder logic with an actual traffic light simulation. For choice two, you can export the sample to program the NI Digital Electronics FPGA Board.

                     

Drag n drop these snippets directly into your Multisim workspace 

 

*I also attached a short version of the NI Multisim for Education PDF specifically for traffic light designs.

What is an SNIPPET file? Section of programming code saved in XML format; code snippets can be saved from Visual Basic, Visual C#, and Visual J projects; they can be edited using the Code Snippet Editor and managed using the Code Snippets Manager. 

Find the attached files below. Hope this helps!

This topic refers to education-specific features of Multisim.

Create a Logic Circuit in NI Multisim - Snippet

Ladder Logic in Multisim

Written by Larsha Johnson
9/18/2021

Software

• Multisim

In Linear Control Systems Lab the topic of programmable logic controllers was introduced. There is a variety of software available on the web to try PLC yourself, in this blog I used NI Multisim 14.2 

🙋Before arriving to this blog you may have asked yourself...how do I implement a logic circuit using ladders within the Multisim environment? Is there any way to learn about ladder logic using a simulated circuit environment such as Multisim?

The answer:

The Education edition of Multisim lets you capture and simulate Ladder Diagrams. These diagrams are electrically based, as opposed to the binary/digital representations employed by ladder logic. Diagrams of this type are used extensively for industrial motor control circuits.

Ladder Diagrams are able to drive output devices or take input data from regular schematics and embed the instructions on how input states affect output states in either the same schematic or separate hierarchical blocks or subcircuits that contain the Ladder Diagram.

Note: Refer to the Multisim User Guide for a complete description of hierarchical blocks and subcircuits.

📌An example of how to create this ladder logic in Multisim is as follows:

1. Select Place/Ladder Rungs.

      

The cursor appears with the rung’s left and right terminators attached.

2. Click to place the first rung and continue clicking and placing until you have placed four rungs as shown below. Right-click to stop placing rungs. 

🔍To add components to the rungs:

1. Select Place/Component, navigate to the Normally Open Relay Contact

(RELAY_CONTACT_NO) click OK.

Note: This device is found in the Ladder Diagrams Group - Ladder Contacts Family.

2. Drop the relay contact directly onto the first rung.

3. Continue in this manner until all relay contacts have been placed. (X4 must be placed and

then wired separately). 

4. Place the lamps (Group - Indicators; Family - Lamp).

5. Place relay coils M1 and M2 on the third and fourth rungs (Group - Ladder Diagrams;

Family - Ladder Relay Coils). 

6. Place switches J1 and J2.

7. Double-click on each switch, select the Value tab, and change the key for J1 to 1 and the

key for J2 to 2. 

🔍To change the controlling device reference for X2 and X4:

1. Double-click on X2 and click the Value tab.

2. Enter M2 in the Controlling Device Reference field and click OK. Repeat for X4. The completed Ladder Diagram appears as shown below.

Embed the circuit file within a PNG image file using a Multisim Snippet and let your peers drag and drop the circuit into Multisim instead. This tutorial explores the new technology and ways to take advantage of it.

👌 Please try our snippet out for yourself and practice designing logic gates own your own.

Sharing Multisim circuit files has never been easier. You can now see a graphical preview of the circuit design before opening, and you no longer need to attach and save files on supported web browsers. This saves you valuable time and increases your productivity.

ARDUINO MKR 1010 & Nano 33 IoT SHIELD

Written by Larsha Johnson

4/29/2019

After a previous post we wrote about creating custom shields using the NI Multisim and NI Ultiboard, we have decided to try it again. Here is our version of a customized compatible MKR 1010 wifi. The dimensions are 61.5mm x 25mm. 28 header pins options and 4 mounting holes. This lightweight bare bones can take your project to the next level. Since the MKR 1010 provides wifi, bluetooth, li-po battery connection with charging & many I/O pins you will want to get your hands on our cool shields. Release date summer 2019. Contact us for pre-purchase.

                               

 

Now about the Nano 33 Iot. Did you know Arduino is releasing four new boards this summer? We did and we are already planning to test them out with our new shields. Our engineering team is hard at work to provide you a custom bare bones boards to get your next gadget going.

Multisim| Stopwatch Timer Cascading 7 Segments 74ls190 74ls47

Stopwatch Timer Cascading 7 Segment Displays

Written by Larsha Johnson
12/19/2015

In this blog a stopwatch is simulated in Multisim and converted to a PCB layout via Ultiboard

Build of material:

1. Two 7 segment displays
2. Resistor packs (100 Ohms) *included in updated model
3. Two 74ls190 (up/down counters)
4. Two 74ls47 (BCD decoder)
5. 555 Timer (1MHz digital clock in Multisim)
6. One toggle switch (up/down)
7. 1 Tact push button switch (reset)

You will need:  7 segment - common anode   74ls190 - up/down counter 74ls47 - decoder/driver Switch Clock pulse - 555 timer or such 5V Power source

automatic_7_seg_counter.ms14 Download File Seven segments are everywhere, clocks, elevators, microwaves, cars, etc. To connect the 7 segments, match A-G segments to the pins of the decoder according to the datasheet. RI, BI, LT should be connected to VCC. The 74ls190 can be preset to a specific start time. ​ Seven segments and decoders are one of the most common types of parts I used to build circuits during my first years studying Computer Engineering Technology. Knowing the difference between anode and cathode use to be a task as well as knowing which type of decoder to use. Now that I have played around with them I am able to build more circuits using the two.

As a beginner you may want to try this 7 Segment Counter project. In the video you will see how I designed an up/down automatic counter and the list of parts I used.

Snippet for drag and drop coming soon.

*Visit our Git page for free files. https://github.com/Bits4Bots

Multisim and Ultiboard| 74ls240 wired 3D PCB

74ls240 Wired

Written by Larsha Johnson

8/20/2015

Ever wonder what is a buffer and why is it useful? In this blog I will show you how to wire a 74ls240 TTL using NI Multisim and NI Ultiboard and some practical applications. First a few keywords:

• Buffer = symbol is a triangle and its input is its output. Purpose is to slow current.

• Octal = eight. The 74ls240 has eight inputs/outputs

• Tri-state/3-state = allows an output port to assume a high impedance (Z) state in addition to low and high values.

• Fan out= number of devices that an output is attached to.

A tri-state buffer or inverting buffer looks like a regular buffer or inverter, except there is an additional "enable" control signal entering the gate. When the enable is "1" the buffer is driving the output; when the enable is "0," the output is turned off ("tri-stated"). 

74ls04 vs 74ls240 Ok the 74ls04 takes its input and outputs the opposite i.e. high=low low=high.
The 74ls240 is a bit more complex...kinda. It can also take its input and output the opposite depending on the G pin. This is what makes the 74ls240 different. The output is determined by pins G (1G or 2G) and pin 1A(1-4)/2A(1-4).  
When the G input is high, the output is "Z" and no electrical current flows through no matter if pins 1A(1-4)/2A(1-4) is high/low.

The 74LS240 belongs to 74XXYY IC series. The 74LS240 is a series of octal buffers and line drivers designed specifically to improve both the performance and density of three-state memory address drivers, clock drivers, and bus-oriented receivers and transmitters. The IC has a wide range of working voltage, a wide range of working conditions, and directly interfaces with CMOS, NMOS, and TTL. The output of the IC always comes in TTL which makes it easy to work with other TTL devices and microcontrollers. The IC 74LS240 is smaller in size and it has a much faster speed which makes it reliable in every kind of device.

NI Multisim Ultiboard- VBB Diode-Resistor Logic Gates AND & OR

Use Diodes and Resistors to Perform Logic

Date: 7/29/2015

Using NI Multisim I created a simply design to show how to use basic components to create an AND & OR gate. 

  

Diode logic gates use diodes to perform OR and AND logic functions as shown in the circuit diagram. Connection of the LED at the output is optional which simply displays the logical state of the output, i.e. the logic state of output is 0 or 1, if LED is off or on, respectively. 

Diodes have the property of easily passing an electrical current in one direction, but not the other. Thus, diodes can act as a logical switch. Diode logic gates are very simple and inexpensive, and can be used effectively in limited space. 

However, they cannot be used extensively due to the obvious logic level shift when gates are connected

in series. In addition, they cannot perform a NOT function, so their usefulness is quite limited. This type of logic circuit is rarely found in integrated form. 

OR Gate (74ls32)

If one or both inputs are at logic “1” (5 volts), the current will flow through one or both diodes. This current passes through the resistor and causes the appearance of a voltage across its terminals, thereby obtaining logic “1” on the output. 

Here only a logic “0” (0 volts) on the output when both inputs are in logic “0”. In this case, the diodes do not conduct, there is no current through the resistor R and there is no voltage across its terminals. As a result the voltage at Vout is the same as ground (0 volts)

AND Gate (74ls08)

When both inputs are at logic “1″, the two diodes are reverse biased and there is no current flowing to ground. Therefore the output is logic “1” because there is no voltage drop across the resistor R.

If one of the inputs is logic “0”, the current will flow through the corresponding diode and through the resistor. Thus the diode anode (the output) will be logic “0”.

This method works fine when the circuits are simple, but there are problems when you have to make interconnections with such gates.

Reference material: 

1. https://www.niser.ac.in/sps/sites/default/files/basic_page/logic%20gate%20circuits.pdf
2. https://electronicsarea.com/or-and-and-logic-gates-with-diodes/
   
3. https://en.wikipedia.org/wiki/AND_gate
   

Multisim|74ls163 Counter Project - 3D View Ultiboard

NI Multisim: 74ls181 ALU 4 Bit Arithmetic Logic Unit

Written by Larsha Johnson
September 6/16/2015

74ls181 ALU 4 Bit Arithmetic Logic Unit

NI Multisim: 74ls181 ALU 4-Bit Logic Unit TTL

74ls181 ALU 4-Bit Logic Unit TTL

What does a 4-Bit ALU do?

Written by: Larsha Johnson

6/16/2015

The 74181 is still used today in retro hacker projects. Here's ow it works and why it's so strange. Is it an all in one logic chip? Well, yes. Since it provides 16 Arithmetic Operations Add, Subtract, Compare, Double, Plus Twelve Other Arithmetic Operations as well as provides all 16 Logic Operations of Two Variables Exclusive — OR( XOR), Compare, AND, NAND, OR, NOR, Plus Ten other Logic Operations!

Why was it designed? To make computing faster in comparison with standard logic gates that was what available at the time. In March 1970, Texas Instruments introduced the 74181 Arithmetic / Logic Unit (ALU) chip, which put a full 4-bit ALU on one fast TTL chip. This chip provided 32 arithmetic and logic functions, as well as carry lookahead for high performance. 

The SN54/74LS181 is a 4-bit Arithmetic Logic Unit (ALU) which can perform all the possible 16 logic, operations on two variables and a variety of arithmetic operations.

The 74181 ALU (arithmetic/logic unit) chip powered many of the minicomputers of the 1970s: it provided fast 4-bit arithmetic and logic functions, and could be combined to handle larger words, making it a key part of many CPUs.

The 74181 is a 4-bit slice arithmetic logic unit (ALU), implemented as a 7400 series TTL integrated circuit. The first complete ALU on a single chip,[1] it was used as the arithmetic/logic core in the CPUs of many historically significant minicomputers and other devices.

The 74181 represents an evolutionary step between the CPUs of the 1960s, which were constructed using discrete logic gates, and today's single-chip microprocessor CPUs. Although no longer used in commercial products, the 74181 is still referenced in computer organization textbooks and technical papers. It is also sometimes used in 'hands-on' college courses, to train future computer architects. 

 

• Provides 16 Arithmetic Operations Add, Subtract, Compare, Double,

Plus Twelve Other Arithmetic Operations 

• Provides all 16 Logic Operations of Two Variables Exclusive — OR,

Compare, AND, NAND, OR, NOR, Plus Ten other Logic Operations

• Full Lookahead for High Speed Arithmetic Operation on Long Words

• Input Clamp Diodes

 FUNCTIONAL DESCRIPTION

The SN54/74LS181 is a 4-bit high speed parallel Arithmetic Logic Unit (ALU). Controlled by the four Function Select Inputs (S0 . . . S3) and the Mode Control Input (M), it can perform all the 16 possible logic operations or 16 different arithmetic operations on active HIGH or active LOW operands. The Function Table lists these operations.

The combinational logic circuitry of the 74181 integrated circuit

Reference articles

Inside the vintage 74181 ALU chip

NI Multisim - SYNCHRONOUS 4-BIT COUNTER 74ls163

74LS Series

• Synchronous 4-bit counter
• Dual-In-Line Package
• 16 pins

http://www.cse.hcmut.edu.vn/~hoangha/uploads/DigitalSystemProject/digitalsystemlab/lab4_2.htm

NI Multisim: Hall Effect Sensor & Magnetic Flux

Written by Larsha Johnson

4/28/2015

Build a magnetic switch using a Hall Effect sensor in Multisim. In its simplest form, the sensor operates as an analog transducer, directly returning a voltage. With a known magnetic field, its distance from the Hall plate can be determined. Using groups of sensors, the relative position of the magnet can be deduced.

https://www.instructables.com/Hall-Effect-Sensor-NI-Multisim/

Hall Effect Sensors convert magnetic flux to a voltage. The output voltage of the sensor depends on the magnetic flux density.

Use this device in conjunction with either the Magnetic Flux Source or the Magnetic Flux Generator. Refer to the Magnetic Flux Source and Magnetic Flux Generator sections for more information.

This topic refers to education-specific features of Multisim

Other components used to simulate the design include the magnetic flux source and magnetic flux generator. These are recommended for simulation studies.

Magnetic Flux Source

This device is used with a Hall Effect Sensor.

The Magnetic Flux Source uses the default B key to change the density and polarity of the magnetic flux impacting on a Hall Effect Sensor. You must specify the sphere of influence of the magnetic flux source by entering an integer value in the Magnetic Channel field in the Value tab of the component’s properties dialog box.

The Magnetic Channel field on the Hall Effect Sensor must have a matching integer value for that sensor to be influenced by the source. No two magnetic flux sources or generators should have the same integer value in the Magnetic Channel field. You can have as many Hall Effect Sensors as you wish to react to any given source/generator and as many different sources/generators as desired as long as each source/generator has a different integer value.

Magnetic Flux Generator

This device is used with a Hall Effect Sensor.

 To locate Hall Effect Sensors, click Search from the Select a Component dialog box, and enter *hall effect sensor* in the Function field.

The Magnetic Flux Generator produces a continuous varying magnetic field (sinusoidal with N and S peaks). You can define the flux density, rate of rotation (translating to frequency) and specify the sphere of influence of the generator by putting a unique integer value in the Magnetic Channel field in the Value tab of the source’s properties dialog box.

The Magnetic Channel field on the Hall Effect Sensor must have a matching integer value for that sensor to be influenced by the generator. No two magnetic flux generators or sources should have the same integer value in the Magnetic Channel field. You can have as many Hall Effect Sensors as you wish to react to any given source/generator and as many different sources/generators as desired as long as each source/generator has a different integer value