SlideShare a Scribd company logo
1 of 4
Download to read offline
Letter Paper
Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013

A Low Cost Wireless Interfacing Device between PS/2
Keyboard and Display
G. N. Tripathi1, Bikash Kant2 and Gurwinder Singh Cheema3
1

FET, MITS, Lakshamangarh, Sikar, Rajasthan
2
LPU, Phagwara, Punjab, India
3
LPU, Phagwara, Punjab, India
E-mail:gyanendra2004@gmail.com1,bikashkant155-2007@lpu.in2 ,g_cheema@live.com3
Abstract—A low cost interface using 8051 micro-controller is
developed for data transition between IBM PS2 key board and
a display device to flash the alphabets, numerals and special
symbols directly to display by entering it from keyboard.
Further additional electronic circuit developed for wireless
data transmission between the two devices so that the displayed
information can be changed using the keyboard from a
distanced place. This helps to change the displayed
information where display is situated at a place that is not
easily accessible and facilitates the display operator.

HT12D) [4]. Physics and media group at MIT media laboratory
used HT12E & HT12D to develop a device for “Parasitic Power
Harvesting in Shoes” [5]. An RF transmitter receiver pair
(A434) is used for wireless communication to develop an
Intelligent Combat Robot for war fields [6], Wireless Control
of an Automated Guided Vehicle is developed using the RF
transmitter and receiver pair [7].
II. ABOUT IBM PS/2 KEYBOARD
IBM introduced the keyboards we use today; IBM PS/2
Keyboard (1987) came with 84-101 keys and 6-pin mini-DIN
connector. It has Bi-direction serial protocol that offers
optional PS/2 scan code set 3 and 17 host-to-keyboard
commands.

Index Terms - Embedded systems, 8051 based system, Keyboard
and display interface.

I. INTRODUCTION
IBM PS/2 key boards are widely used input device to
give input in the form of numerals alphabets and special
symbols. There is mean delay of 10 m-sec and a random error
of +5 or -5 m-sec on PS/2 keyboard [1]. For a display device
we need to give input to change the display in a real time
situation. The PS/2 key board is use full in wide variety of
application and its easy availability in the market is
advantageous.Keyboards are nothing but a large matrix of
keys, there is one on-board processor also called keyboard
encoder that monitors all the keys. The processor may vary
from one keyboard to another keyboard depending on brand
but they do same basic process of monitoring the keys that
which one is being pressed/released the appropriate data is
send to the system for which key board is input device.
Processor also takes care of the de-bouncing and buffers the
required data in its 16-byte buffer [2].
The key board processor does the monitoring or
“scanning” of key matrix. The process incorporates finding
of key which is pressed, released, or held down and
information in the form of data packet, “scan code” is send
to your computer. The two types of “scan codes” are “make
codes” and “break codes”. A make code is information that is
sent when a key is pressed. A break code is information that
is sent when a key is released. A set of make and break code
for every key comprises a “scan code set”[3].The microcontroller (8051), interfaced with PS/2 keyboard, tracks the
“scan code” generated by the keyboard and interprets ‘scan
code’ to corresponding alphabet, numeral or symbol. The
ASCII code corresponding to the alphabet, numeral or symbol
is transmitted wirelessly to the display using RF transmitter
and receiver part with encoder and decoder (HT12E and the
© 2013 ACEEE
DOI: 01.IJRTET.8.2.559

A. PS/2 Key Board Connector
To connect the keyboard with microcontroller the standard
convention of the connector is followed. PS/2 key board
connector is a 6 pin mini-DIN Figure1. The IBM keyboard
uses the data to transfer the data and the clock pin is used for
clock based synchronised data transfer. The Vcc (+5V) and
ground pins are used to give power supply to the keyboard.
6-pin Mini-DIN (PS/2):
1 - Data
2 - Not Implemented
3 - Ground
4 - Vcc (+5V)
5 - Clock
6 - Not Implemented
Fig. 1. PS/2 connector [2]

B. Electrical Specification
With a Vcc specification of +4.5V to +5.5V the max drawing
current for key board is 275 mA. To connect the data and
clock pins with microcontroller pull up resister should be
connected, an external pull up registers is used in case there
is no internal pull up resisters connected to microcontroller I/
O pins.
C. 2.3 Data Communication
The bidirectional synchronous serial protocol is
implemented in PS/2 keyboard. Data is send byte by byte,
one byte of data is sent in a packet of 11 or 12 bit data packet.
The transfer of one byte data from key board to
microcontroller is sent is a packet of 11 bit TableI.
78
Letter Paper
Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013
III. TRANSMITTER SECTION

TABLE I. DATA PACKET

The transmitting section is the PS2 keyboard side which
includes the PS2 keyboard, microcontroller, HT12E and the
RF transmitter module Figure3.
The Data line changes state when Clock is high and that
data is valid when Clock is low TableII. The clock frequency
is 10-16.7 kHz and the maximum allowed is 30 KHz. The time
from the rising edge of a clock pulse to a Data transition must
be at least 5 microseconds. The time from a data transition to
the falling edge of a clock pulse must be at least 5
microseconds and no greater than 25 microseconds figure2.
Fig. 3. Transmitter end
TABLE II. D ATA, CLOCK, B US STATE

The PS2 keyboard sends the data serially to the
microcontroller and the microcontroller interprets the hex code
sent by the keyboard as discussed earlier.
A. HT12E
HT12E is an encoder IC which is capable of encoding
information which consists of 8 address bits and 4 data bits.
The operating voltage for HT12E is specified as 2.4V~12V
and Low standby current is 0.1A at 5V. Address pins are
specified as A0~A7, these pins can be externally set to +5V
or left open according to the requirement of address that is
allocated for secured transmission to the receiver. D8~D11
are the Input pins for data, Dout pin gives the data output
serially Figure4. The input data to encoder is parallel and the
output data is serial and the output is given to the RF module
for the transmission.
The data input data to HT12E is in the form of nibbles
(lower and upper nibble), that is transferred parallel. The
address set on the pins of this HT12E should be same as of
the address of decoder HT12D on receiver side, only then
the data can be transferred can be decoded properly. A
dynamic address allocation for transmitter and receiver can
be done by connecting address pin to port pin of
microcontroller and program it properly at both transmitter
and receiver end. Address allocation gives advantage that
the data can be sent only to the specified receiver by the
transmitter. The serial data is sent to the RF module by
connecting Dout pin of HT12E to the data pin ‘D’ of RF
transmitter.

Fig. 2. Timing diagram [2]

D. Scan Codes
The keyboard sends the different scan codes for each
different key pressed Table III. The scan code sent is
independent of the condition that whether the caps are on or
off, i.e. same scan code will be sent when the caps are on and
when caps are off. For example the key ‘A’ sends the ‘1C’
(Hex), key ‘Q’ sends the ‘15’ (hex), F1 key sends the ‘05’
(hex), etc. More characters or the longer scan codes are
generated by some keys like PRT SCR, PAUSE, etc. The codes
sent by the keyboard are HEX codes.
TABLE II. SCAN

CODE

Fig. 4. HT12E and RF module interconnections [10]

© 2013 ACEEE
DOI: 01.IJRTET.8.2. 559

79
Letter Paper
Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013
IV. RECEIVER SECTION

running hand. A theoretical model presents the upper and
lower-bound text-entry rates on QWERTY keyboard [8]. The
result is given in tabular form in Figure7.Considering 3475
peoples typing speed the statistics says that mean of speed
of typing is 40 words per minute (WPM), median is 38 WPM
and mode is 31 WPM with standard deviation of + 16.7 WPM
from the median [9].

The receiving section is on display side which includes
the RF receiver module, HT12D, microcontroller, and display
Figure5.

Fig. 5. Reciever end

The wireless data is received by the RF module serially
and the HT12D receives the serial data and give the parallel
data output to the controller after decoding it.

Fig. 8. Typing speed (statistically)[8]

With time calculation the response of human to press key
board key and delay in pressing keyboard key is in range of
millisecond where the microprocessor response time is in the
range of microseconds Figure8. With due consideration we
can say that there will not be time issue in such case. However
the display response time is one factor that depends on
display type, colour and light condition and can be adjusted
by changing microprocessor program using delays as per
the practical situation.

A. HT12D
HT12D is a decoder IC which is capable of decoding
information which consists of 8 address bits and 4 data bits.
HT12D has operates at voltage specified as 2.4V~12V, and
provides low standby current. Address pin A0~A7 are the
Input pins for address externally set to +5V or left open as
per the address specified on transmitter side. D8~D11 are
Output data pins, Din is the Serial data input pin, VT is for the
valid transmission, must be active high Figure6. The input
data to decoder is serial and the output data is parallel. Data
pin ‘D’ of RF receiver module is connected to Din pin of
HD12D.

VI. SIMULATION RESULT AND T EST OF HARDWIRED MODEL

Fig. 6. RF and the HD12D interconnections [10]
Fig. 9. Simulation result on Proteus

V. TYPING SPEED AND DISPLAY RESPONSE
A consideration of typing speed is important where it is a
need to get the display content changed while typing in

Fig. 10. Hardwired circuit
Fig. 7. Theoretical typing speed [8]

© 2013 ACEEE
DOI: 01.IJRTET.8.2.559

80
Letter Paper
Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013
Simulation of the circuit is performed on PROTEUS tool. The
simulation result for display on LED was good. The hardwired
circuit performance was as per the simulation result of
PROTEUS Figure9. The program written for alphabets,
numerals and special symbols were displayed on LED
according to the key is pressed on keyboard. The range or
transmitter and receiver are dependent on antenna quality
with the antenna used transmitter and receiver communication
was unaffected up to 90 meter range.

Copyright 1998-2010, Adam Chapweske. Retrieved from http:/
/www.Computer-Engineering.org
[3] Celik, C. (2004). Using PS/2 keyboards in embedded systems.
In Istanbul-Turkey: Lima Endustriyel Bilgisayar. Retrieved
from www.lima.com.tr
[4] Kadu, R. A., More, V. A., Chitte, P. P., Rana, J. G., & Bendre,
M. R. (n.d.). Wireless control and monitoring of robotic arm
(swords). International  Journal  of  Computer Technology  and
Electronics Engineering (IJCTEE), 2(1), doi: ISSN 2249-6343
[5] Kymissis, J., Kendall, C., Paradiso, J., & Gershenfeld, N.
(1998, August). Parasitic power harvesting in shoes. The
second IEEE International conference on wearable computing.
[6] Bhargavi, D. S., & Manjunath, S. (2011). Design of an intelligent
combat robot for war fields.International Journal of Advanced
Computer Science and Applications (IJACSA) , 2(8), 64-70.
Retrieved from www.ijacsa.thesai.org
[7] Piyare, R. K., & Singh, R. (2011, March). Wireless control of
an automated guided vehicle. In Proceedings of the International
MultiConference of Engineers and Computer Scientists. doi:
ISSN: 2078-0966
[8] Soukoreff , R. W., & MacKenzie, I. S. (1995). Theoretical
upper and lower bounds on typing speed using a stylus and
soft keyboard . Behaviour & Information Technology, 14, 370379.
[9] Ostrach, T. R. (1997). Typing speed: How fast is average :
4,000 typing scores statistically analyzed and interpreted. In
Orlando, FL: Five Star Staffing.
[10] Sheth, V. J., & Suryawanshi, P. V. On the Design and
Development of a Motion Control System using Accelerometer
and RF Communication.

CONCLUSION
Both LCD and LED array are used as display to test the
transmitter and receiver circuit working Figure10. It was found
that working model was performing well within the practical
distance range of 60-90 meter between transmitter and
receiver, which depends on antenna attached with transmitter
and receiver and the obstructions.
REFERENCES
[1] Segalowitz, S. J., & Graves , R. E. (1990). “Instrumentation
and Technique”, Suitability of the IBM XT, AT and PS/2
keyboard, mouse, and game port as response device in reaction
time paradigms . Behavioural Research Methods, Instruments
& computers ,22(3), 283-289.
[2] Chapweske, A. (2003).The PS/2 mouse/keyboard protocol.

© 2013 ACEEE
DOI: 01.IJRTET.8.2. 559

81

More Related Content

What's hot

Project on Electronic voting machine
Project on Electronic   voting   machineProject on Electronic   voting   machine
Project on Electronic voting machineDeepak Kumar
 
Interactive irrigation system through mobile with ivr response
Interactive irrigation system through mobile with ivr responseInteractive irrigation system through mobile with ivr response
Interactive irrigation system through mobile with ivr responseeSAT Publishing House
 
Fpga based heart rate monitoring system using gsm
Fpga based heart rate monitoring system using gsmFpga based heart rate monitoring system using gsm
Fpga based heart rate monitoring system using gsmAnuj Arora
 
INTERFACING WITH INTEL 8251A (USART)
INTERFACING WITH INTEL 8251A (USART)INTERFACING WITH INTEL 8251A (USART)
INTERFACING WITH INTEL 8251A (USART)Prof Ansari
 
RC Car detailed analysis
RC Car detailed analysisRC Car detailed analysis
RC Car detailed analysisMohd Akram
 
Serial Io
Serial IoSerial Io
Serial IoAisu
 
Glossary of Technical Terms for Process Weighing
Glossary of Technical Terms for Process WeighingGlossary of Technical Terms for Process Weighing
Glossary of Technical Terms for Process WeighingPower Specialties, Inc.
 
Password based door lock system using 8051 microcontroller final report
Password based door lock system using 8051 microcontroller final reportPassword based door lock system using 8051 microcontroller final report
Password based door lock system using 8051 microcontroller final reportChinaraja Baratam
 
Robotic Project - published paper
Robotic Project - published paperRobotic Project - published paper
Robotic Project - published paperRobert Rosier
 
L14 kb-lcd-interfacing-with-atmega328 p
L14 kb-lcd-interfacing-with-atmega328 pL14 kb-lcd-interfacing-with-atmega328 p
L14 kb-lcd-interfacing-with-atmega328 prsamurti
 
Network Based Data Acquisition and Logging System using PIC Microcontroller
Network Based Data Acquisition and Logging System using PIC MicrocontrollerNetwork Based Data Acquisition and Logging System using PIC Microcontroller
Network Based Data Acquisition and Logging System using PIC MicrocontrollerCSCJournals
 
Imx53 uart- GUIDE BOOK
Imx53 uart- GUIDE BOOKImx53 uart- GUIDE BOOK
Imx53 uart- GUIDE BOOKShahrukh Javed
 

What's hot (19)

Ju2416921695
Ju2416921695Ju2416921695
Ju2416921695
 
Project on Electronic voting machine
Project on Electronic   voting   machineProject on Electronic   voting   machine
Project on Electronic voting machine
 
G05134851
G05134851G05134851
G05134851
 
Password based door locksystem
Password  based door locksystemPassword  based door locksystem
Password based door locksystem
 
Interactive irrigation system through mobile with ivr response
Interactive irrigation system through mobile with ivr responseInteractive irrigation system through mobile with ivr response
Interactive irrigation system through mobile with ivr response
 
Fpga based heart rate monitoring system using gsm
Fpga based heart rate monitoring system using gsmFpga based heart rate monitoring system using gsm
Fpga based heart rate monitoring system using gsm
 
Serial communication of microcontroller 8051
Serial communication of microcontroller 8051Serial communication of microcontroller 8051
Serial communication of microcontroller 8051
 
INTERFACING WITH INTEL 8251A (USART)
INTERFACING WITH INTEL 8251A (USART)INTERFACING WITH INTEL 8251A (USART)
INTERFACING WITH INTEL 8251A (USART)
 
RC Car detailed analysis
RC Car detailed analysisRC Car detailed analysis
RC Car detailed analysis
 
Serial Io
Serial IoSerial Io
Serial Io
 
Glossary of Technical Terms for Process Weighing
Glossary of Technical Terms for Process WeighingGlossary of Technical Terms for Process Weighing
Glossary of Technical Terms for Process Weighing
 
Password based door lock system using 8051 microcontroller final report
Password based door lock system using 8051 microcontroller final reportPassword based door lock system using 8051 microcontroller final report
Password based door lock system using 8051 microcontroller final report
 
Project
ProjectProject
Project
 
Robotic Project - published paper
Robotic Project - published paperRobotic Project - published paper
Robotic Project - published paper
 
L14 kb-lcd-interfacing-with-atmega328 p
L14 kb-lcd-interfacing-with-atmega328 pL14 kb-lcd-interfacing-with-atmega328 p
L14 kb-lcd-interfacing-with-atmega328 p
 
8251 USART
8251 USART8251 USART
8251 USART
 
Network Based Data Acquisition and Logging System using PIC Microcontroller
Network Based Data Acquisition and Logging System using PIC MicrocontrollerNetwork Based Data Acquisition and Logging System using PIC Microcontroller
Network Based Data Acquisition and Logging System using PIC Microcontroller
 
Imx53 uart- GUIDE BOOK
Imx53 uart- GUIDE BOOKImx53 uart- GUIDE BOOK
Imx53 uart- GUIDE BOOK
 
8051 serial communication-UART
8051 serial communication-UART8051 serial communication-UART
8051 serial communication-UART
 

Similar to A Low Cost Wireless Interfacing Device between PS/2 Keyboard and Display

Technical seminar project stalin babu m 116_f1a0471
Technical seminar project stalin babu m 116_f1a0471Technical seminar project stalin babu m 116_f1a0471
Technical seminar project stalin babu m 116_f1a0471STALIN BABU
 
Final Report - morse code.pdf
Final Report - morse code.pdfFinal Report - morse code.pdf
Final Report - morse code.pdfHanaBaSabaa
 
Real-Time Monitoring and Control System for Industry
Real-Time Monitoring and Control System for IndustryReal-Time Monitoring and Control System for Industry
Real-Time Monitoring and Control System for Industryijsrd.com
 
GSM based patient monitoring system
GSM based patient monitoring systemGSM based patient monitoring system
GSM based patient monitoring systemssvarma k
 
KYL 300H wireless module user manual
KYL 300H wireless module user manualKYL 300H wireless module user manual
KYL 300H wireless module user manualSunny Zhou
 
Serial Communication Interface with Error Detection
Serial Communication Interface with Error DetectionSerial Communication Interface with Error Detection
Serial Communication Interface with Error Detectioniosrjce
 
Microprocessorlabmanual ee0310
Microprocessorlabmanual ee0310Microprocessorlabmanual ee0310
Microprocessorlabmanual ee0310DHEERAJ DHAKAR
 
Implementation of MIL-STD1553 using Microcontroller Atmega 328P
Implementation of MIL-STD1553 using Microcontroller Atmega 328PImplementation of MIL-STD1553 using Microcontroller Atmega 328P
Implementation of MIL-STD1553 using Microcontroller Atmega 328PIRJET Journal
 
SOCIAL NETWORK FOR SMART DEVICES USING EMBEDDED ETHERNET
SOCIAL NETWORK FOR SMART DEVICES USING EMBEDDED ETHERNETSOCIAL NETWORK FOR SMART DEVICES USING EMBEDDED ETHERNET
SOCIAL NETWORK FOR SMART DEVICES USING EMBEDDED ETHERNETcseij
 
Home Automation with MATLAB and ARDUINO Interface
Home Automation with MATLAB and ARDUINO InterfaceHome Automation with MATLAB and ARDUINO Interface
Home Automation with MATLAB and ARDUINO InterfaceAlok Tiwari
 

Similar to A Low Cost Wireless Interfacing Device between PS/2 Keyboard and Display (20)

Technical seminar project stalin babu m 116_f1a0471
Technical seminar project stalin babu m 116_f1a0471Technical seminar project stalin babu m 116_f1a0471
Technical seminar project stalin babu m 116_f1a0471
 
project 3 full report
project 3 full reportproject 3 full report
project 3 full report
 
Final Report - morse code.pdf
Final Report - morse code.pdfFinal Report - morse code.pdf
Final Report - morse code.pdf
 
Real-Time Monitoring and Control System for Industry
Real-Time Monitoring and Control System for IndustryReal-Time Monitoring and Control System for Industry
Real-Time Monitoring and Control System for Industry
 
GSM based patient monitoring system
GSM based patient monitoring systemGSM based patient monitoring system
GSM based patient monitoring system
 
Jy3717961800
Jy3717961800Jy3717961800
Jy3717961800
 
KYL 300H wireless module user manual
KYL 300H wireless module user manualKYL 300H wireless module user manual
KYL 300H wireless module user manual
 
ivr system
ivr systemivr system
ivr system
 
Cdma
CdmaCdma
Cdma
 
Serial Communication Interface with Error Detection
Serial Communication Interface with Error DetectionSerial Communication Interface with Error Detection
Serial Communication Interface with Error Detection
 
M010617376
M010617376M010617376
M010617376
 
Microprocessorlabmanual ee0310
Microprocessorlabmanual ee0310Microprocessorlabmanual ee0310
Microprocessorlabmanual ee0310
 
Smart home
Smart homeSmart home
Smart home
 
Smart home copy
Smart home   copySmart home   copy
Smart home copy
 
Smart home
Smart homeSmart home
Smart home
 
Implementation of MIL-STD1553 using Microcontroller Atmega 328P
Implementation of MIL-STD1553 using Microcontroller Atmega 328PImplementation of MIL-STD1553 using Microcontroller Atmega 328P
Implementation of MIL-STD1553 using Microcontroller Atmega 328P
 
Industrialtraining
IndustrialtrainingIndustrialtraining
Industrialtraining
 
SOCIAL NETWORK FOR SMART DEVICES USING EMBEDDED ETHERNET
SOCIAL NETWORK FOR SMART DEVICES USING EMBEDDED ETHERNETSOCIAL NETWORK FOR SMART DEVICES USING EMBEDDED ETHERNET
SOCIAL NETWORK FOR SMART DEVICES USING EMBEDDED ETHERNET
 
Home Automation with MATLAB and ARDUINO Interface
Home Automation with MATLAB and ARDUINO InterfaceHome Automation with MATLAB and ARDUINO Interface
Home Automation with MATLAB and ARDUINO Interface
 
D5242023
D5242023D5242023
D5242023
 

More from idescitation (20)

65 113-121
65 113-12165 113-121
65 113-121
 
69 122-128
69 122-12869 122-128
69 122-128
 
71 338-347
71 338-34771 338-347
71 338-347
 
72 129-135
72 129-13572 129-135
72 129-135
 
74 136-143
74 136-14374 136-143
74 136-143
 
80 152-157
80 152-15780 152-157
80 152-157
 
82 348-355
82 348-35582 348-355
82 348-355
 
84 11-21
84 11-2184 11-21
84 11-21
 
62 328-337
62 328-33762 328-337
62 328-337
 
46 102-112
46 102-11246 102-112
46 102-112
 
47 292-298
47 292-29847 292-298
47 292-298
 
49 299-305
49 299-30549 299-305
49 299-305
 
57 306-311
57 306-31157 306-311
57 306-311
 
60 312-318
60 312-31860 312-318
60 312-318
 
5 1-10
5 1-105 1-10
5 1-10
 
11 69-81
11 69-8111 69-81
11 69-81
 
14 284-291
14 284-29114 284-291
14 284-291
 
15 82-87
15 82-8715 82-87
15 82-87
 
29 88-96
29 88-9629 88-96
29 88-96
 
43 97-101
43 97-10143 97-101
43 97-101
 

Recently uploaded

How to Set Up a One-to-Many Relationship Between Two Models in Odoo 17
How to Set Up a One-to-Many Relationship Between Two Models in Odoo 17How to Set Up a One-to-Many Relationship Between Two Models in Odoo 17
How to Set Up a One-to-Many Relationship Between Two Models in Odoo 17Celine George
 
Natural Numbers, Whole Numbers, Integers.pdf
Natural Numbers, Whole Numbers, Integers.pdfNatural Numbers, Whole Numbers, Integers.pdf
Natural Numbers, Whole Numbers, Integers.pdfPranav Sharma
 
Chemistry and formulation of para phenylenediamine based hair dye.
Chemistry and formulation of para phenylenediamine based hair dye.Chemistry and formulation of para phenylenediamine based hair dye.
Chemistry and formulation of para phenylenediamine based hair dye.ruchisuryawanshi1234
 
The Giver Project Summary - Michael Q Trucks
The Giver Project Summary - Michael Q TrucksThe Giver Project Summary - Michael Q Trucks
The Giver Project Summary - Michael Q TrucksMichael Trucks
 
How to Create Manifest File in Odoo 17 ERP
How to Create Manifest File in Odoo 17 ERPHow to Create Manifest File in Odoo 17 ERP
How to Create Manifest File in Odoo 17 ERPCeline George
 
Auto-Reconcile Feature in the Odoo 17 ERP
Auto-Reconcile Feature in the Odoo 17 ERPAuto-Reconcile Feature in the Odoo 17 ERP
Auto-Reconcile Feature in the Odoo 17 ERPCeline George
 
To test decimal representation of rational Numbers.pdf
To test decimal representation of rational Numbers.pdfTo test decimal representation of rational Numbers.pdf
To test decimal representation of rational Numbers.pdfPranav Sharma
 
LANGUAGE AND BRAIN :Relationship Between Language and the Brain
LANGUAGE AND BRAIN :Relationship Between Language and the BrainLANGUAGE AND BRAIN :Relationship Between Language and the Brain
LANGUAGE AND BRAIN :Relationship Between Language and the BrainImran Kakar
 
Protein Structure - threading Protein modelling pptx
Protein Structure - threading Protein modelling pptxProtein Structure - threading Protein modelling pptx
Protein Structure - threading Protein modelling pptxvidhisharma994099
 
3.28.24 The Poor People's Campaign.pptx
3.28.24  The Poor People's Campaign.pptx3.28.24  The Poor People's Campaign.pptx
3.28.24 The Poor People's Campaign.pptxmary850239
 
burningissueissueburnburnburnburnburnburn
burningissueissueburnburnburnburnburnburnburningissueissueburnburnburnburnburnburn
burningissueissueburnburnburnburnburnburnmcueva1
 
Personal Brand Exploration- Valeria Alvarez
Personal Brand Exploration- Valeria AlvarezPersonal Brand Exploration- Valeria Alvarez
Personal Brand Exploration- Valeria AlvarezValeriaAlvarez967687
 
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRA
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRADUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRA
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRATanmoy Mishra
 
MS4 -seq3- citizenship& community lexis & conditional 1& imperative & text ...
MS4 -seq3-  citizenship& community lexis & conditional 1&  imperative & text ...MS4 -seq3-  citizenship& community lexis & conditional 1&  imperative & text ...
MS4 -seq3- citizenship& community lexis & conditional 1& imperative & text ...Mr Bounab Samir
 
ENGLISH 9 Quarter 4 Week 1 powerpoint Presentation
ENGLISH 9 Quarter 4 Week 1 powerpoint PresentationENGLISH 9 Quarter 4 Week 1 powerpoint Presentation
ENGLISH 9 Quarter 4 Week 1 powerpoint PresentationCarlaTorre7
 
Empowering Student Engagement with Open Education
Empowering Student Engagement with Open EducationEmpowering Student Engagement with Open Education
Empowering Student Engagement with Open EducationLorna Campbell
 
EBUS5423 Data Analytics and Reporting Bl
EBUS5423 Data Analytics and Reporting BlEBUS5423 Data Analytics and Reporting Bl
EBUS5423 Data Analytics and Reporting BlDr. Bruce A. Johnson
 
How to Send Emails From Odoo 17 Using Code
How to Send Emails From Odoo 17 Using CodeHow to Send Emails From Odoo 17 Using Code
How to Send Emails From Odoo 17 Using CodeCeline George
 
DR. NNC LAPAROSCOPY IN PREGNANCY IAGE VARANASI, 17TH MARCH 2024.pptx
DR. NNC LAPAROSCOPY IN PREGNANCY IAGE VARANASI, 17TH MARCH 2024.pptxDR. NNC LAPAROSCOPY IN PREGNANCY IAGE VARANASI, 17TH MARCH 2024.pptx
DR. NNC LAPAROSCOPY IN PREGNANCY IAGE VARANASI, 17TH MARCH 2024.pptxNiranjan Chavan
 

Recently uploaded (20)

How to Set Up a One-to-Many Relationship Between Two Models in Odoo 17
How to Set Up a One-to-Many Relationship Between Two Models in Odoo 17How to Set Up a One-to-Many Relationship Between Two Models in Odoo 17
How to Set Up a One-to-Many Relationship Between Two Models in Odoo 17
 
Natural Numbers, Whole Numbers, Integers.pdf
Natural Numbers, Whole Numbers, Integers.pdfNatural Numbers, Whole Numbers, Integers.pdf
Natural Numbers, Whole Numbers, Integers.pdf
 
Chemistry and formulation of para phenylenediamine based hair dye.
Chemistry and formulation of para phenylenediamine based hair dye.Chemistry and formulation of para phenylenediamine based hair dye.
Chemistry and formulation of para phenylenediamine based hair dye.
 
The Giver Project Summary - Michael Q Trucks
The Giver Project Summary - Michael Q TrucksThe Giver Project Summary - Michael Q Trucks
The Giver Project Summary - Michael Q Trucks
 
How to Create Manifest File in Odoo 17 ERP
How to Create Manifest File in Odoo 17 ERPHow to Create Manifest File in Odoo 17 ERP
How to Create Manifest File in Odoo 17 ERP
 
Auto-Reconcile Feature in the Odoo 17 ERP
Auto-Reconcile Feature in the Odoo 17 ERPAuto-Reconcile Feature in the Odoo 17 ERP
Auto-Reconcile Feature in the Odoo 17 ERP
 
March 2024 Directors Meeting, Division of Student Affairs and Academic Support
March 2024 Directors Meeting, Division of Student Affairs and Academic SupportMarch 2024 Directors Meeting, Division of Student Affairs and Academic Support
March 2024 Directors Meeting, Division of Student Affairs and Academic Support
 
To test decimal representation of rational Numbers.pdf
To test decimal representation of rational Numbers.pdfTo test decimal representation of rational Numbers.pdf
To test decimal representation of rational Numbers.pdf
 
LANGUAGE AND BRAIN :Relationship Between Language and the Brain
LANGUAGE AND BRAIN :Relationship Between Language and the BrainLANGUAGE AND BRAIN :Relationship Between Language and the Brain
LANGUAGE AND BRAIN :Relationship Between Language and the Brain
 
Protein Structure - threading Protein modelling pptx
Protein Structure - threading Protein modelling pptxProtein Structure - threading Protein modelling pptx
Protein Structure - threading Protein modelling pptx
 
3.28.24 The Poor People's Campaign.pptx
3.28.24  The Poor People's Campaign.pptx3.28.24  The Poor People's Campaign.pptx
3.28.24 The Poor People's Campaign.pptx
 
burningissueissueburnburnburnburnburnburn
burningissueissueburnburnburnburnburnburnburningissueissueburnburnburnburnburnburn
burningissueissueburnburnburnburnburnburn
 
Personal Brand Exploration- Valeria Alvarez
Personal Brand Exploration- Valeria AlvarezPersonal Brand Exploration- Valeria Alvarez
Personal Brand Exploration- Valeria Alvarez
 
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRA
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRADUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRA
DUST OF SNOW_BY ROBERT FROST_EDITED BY_ TANMOY MISHRA
 
MS4 -seq3- citizenship& community lexis & conditional 1& imperative & text ...
MS4 -seq3-  citizenship& community lexis & conditional 1&  imperative & text ...MS4 -seq3-  citizenship& community lexis & conditional 1&  imperative & text ...
MS4 -seq3- citizenship& community lexis & conditional 1& imperative & text ...
 
ENGLISH 9 Quarter 4 Week 1 powerpoint Presentation
ENGLISH 9 Quarter 4 Week 1 powerpoint PresentationENGLISH 9 Quarter 4 Week 1 powerpoint Presentation
ENGLISH 9 Quarter 4 Week 1 powerpoint Presentation
 
Empowering Student Engagement with Open Education
Empowering Student Engagement with Open EducationEmpowering Student Engagement with Open Education
Empowering Student Engagement with Open Education
 
EBUS5423 Data Analytics and Reporting Bl
EBUS5423 Data Analytics and Reporting BlEBUS5423 Data Analytics and Reporting Bl
EBUS5423 Data Analytics and Reporting Bl
 
How to Send Emails From Odoo 17 Using Code
How to Send Emails From Odoo 17 Using CodeHow to Send Emails From Odoo 17 Using Code
How to Send Emails From Odoo 17 Using Code
 
DR. NNC LAPAROSCOPY IN PREGNANCY IAGE VARANASI, 17TH MARCH 2024.pptx
DR. NNC LAPAROSCOPY IN PREGNANCY IAGE VARANASI, 17TH MARCH 2024.pptxDR. NNC LAPAROSCOPY IN PREGNANCY IAGE VARANASI, 17TH MARCH 2024.pptx
DR. NNC LAPAROSCOPY IN PREGNANCY IAGE VARANASI, 17TH MARCH 2024.pptx
 

A Low Cost Wireless Interfacing Device between PS/2 Keyboard and Display

  • 1. Letter Paper Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013 A Low Cost Wireless Interfacing Device between PS/2 Keyboard and Display G. N. Tripathi1, Bikash Kant2 and Gurwinder Singh Cheema3 1 FET, MITS, Lakshamangarh, Sikar, Rajasthan 2 LPU, Phagwara, Punjab, India 3 LPU, Phagwara, Punjab, India E-mail:gyanendra2004@gmail.com1,bikashkant155-2007@lpu.in2 ,g_cheema@live.com3 Abstract—A low cost interface using 8051 micro-controller is developed for data transition between IBM PS2 key board and a display device to flash the alphabets, numerals and special symbols directly to display by entering it from keyboard. Further additional electronic circuit developed for wireless data transmission between the two devices so that the displayed information can be changed using the keyboard from a distanced place. This helps to change the displayed information where display is situated at a place that is not easily accessible and facilitates the display operator. HT12D) [4]. Physics and media group at MIT media laboratory used HT12E & HT12D to develop a device for “Parasitic Power Harvesting in Shoes” [5]. An RF transmitter receiver pair (A434) is used for wireless communication to develop an Intelligent Combat Robot for war fields [6], Wireless Control of an Automated Guided Vehicle is developed using the RF transmitter and receiver pair [7]. II. ABOUT IBM PS/2 KEYBOARD IBM introduced the keyboards we use today; IBM PS/2 Keyboard (1987) came with 84-101 keys and 6-pin mini-DIN connector. It has Bi-direction serial protocol that offers optional PS/2 scan code set 3 and 17 host-to-keyboard commands. Index Terms - Embedded systems, 8051 based system, Keyboard and display interface. I. INTRODUCTION IBM PS/2 key boards are widely used input device to give input in the form of numerals alphabets and special symbols. There is mean delay of 10 m-sec and a random error of +5 or -5 m-sec on PS/2 keyboard [1]. For a display device we need to give input to change the display in a real time situation. The PS/2 key board is use full in wide variety of application and its easy availability in the market is advantageous.Keyboards are nothing but a large matrix of keys, there is one on-board processor also called keyboard encoder that monitors all the keys. The processor may vary from one keyboard to another keyboard depending on brand but they do same basic process of monitoring the keys that which one is being pressed/released the appropriate data is send to the system for which key board is input device. Processor also takes care of the de-bouncing and buffers the required data in its 16-byte buffer [2]. The key board processor does the monitoring or “scanning” of key matrix. The process incorporates finding of key which is pressed, released, or held down and information in the form of data packet, “scan code” is send to your computer. The two types of “scan codes” are “make codes” and “break codes”. A make code is information that is sent when a key is pressed. A break code is information that is sent when a key is released. A set of make and break code for every key comprises a “scan code set”[3].The microcontroller (8051), interfaced with PS/2 keyboard, tracks the “scan code” generated by the keyboard and interprets ‘scan code’ to corresponding alphabet, numeral or symbol. The ASCII code corresponding to the alphabet, numeral or symbol is transmitted wirelessly to the display using RF transmitter and receiver part with encoder and decoder (HT12E and the © 2013 ACEEE DOI: 01.IJRTET.8.2.559 A. PS/2 Key Board Connector To connect the keyboard with microcontroller the standard convention of the connector is followed. PS/2 key board connector is a 6 pin mini-DIN Figure1. The IBM keyboard uses the data to transfer the data and the clock pin is used for clock based synchronised data transfer. The Vcc (+5V) and ground pins are used to give power supply to the keyboard. 6-pin Mini-DIN (PS/2): 1 - Data 2 - Not Implemented 3 - Ground 4 - Vcc (+5V) 5 - Clock 6 - Not Implemented Fig. 1. PS/2 connector [2] B. Electrical Specification With a Vcc specification of +4.5V to +5.5V the max drawing current for key board is 275 mA. To connect the data and clock pins with microcontroller pull up resister should be connected, an external pull up registers is used in case there is no internal pull up resisters connected to microcontroller I/ O pins. C. 2.3 Data Communication The bidirectional synchronous serial protocol is implemented in PS/2 keyboard. Data is send byte by byte, one byte of data is sent in a packet of 11 or 12 bit data packet. The transfer of one byte data from key board to microcontroller is sent is a packet of 11 bit TableI. 78
  • 2. Letter Paper Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013 III. TRANSMITTER SECTION TABLE I. DATA PACKET The transmitting section is the PS2 keyboard side which includes the PS2 keyboard, microcontroller, HT12E and the RF transmitter module Figure3. The Data line changes state when Clock is high and that data is valid when Clock is low TableII. The clock frequency is 10-16.7 kHz and the maximum allowed is 30 KHz. The time from the rising edge of a clock pulse to a Data transition must be at least 5 microseconds. The time from a data transition to the falling edge of a clock pulse must be at least 5 microseconds and no greater than 25 microseconds figure2. Fig. 3. Transmitter end TABLE II. D ATA, CLOCK, B US STATE The PS2 keyboard sends the data serially to the microcontroller and the microcontroller interprets the hex code sent by the keyboard as discussed earlier. A. HT12E HT12E is an encoder IC which is capable of encoding information which consists of 8 address bits and 4 data bits. The operating voltage for HT12E is specified as 2.4V~12V and Low standby current is 0.1A at 5V. Address pins are specified as A0~A7, these pins can be externally set to +5V or left open according to the requirement of address that is allocated for secured transmission to the receiver. D8~D11 are the Input pins for data, Dout pin gives the data output serially Figure4. The input data to encoder is parallel and the output data is serial and the output is given to the RF module for the transmission. The data input data to HT12E is in the form of nibbles (lower and upper nibble), that is transferred parallel. The address set on the pins of this HT12E should be same as of the address of decoder HT12D on receiver side, only then the data can be transferred can be decoded properly. A dynamic address allocation for transmitter and receiver can be done by connecting address pin to port pin of microcontroller and program it properly at both transmitter and receiver end. Address allocation gives advantage that the data can be sent only to the specified receiver by the transmitter. The serial data is sent to the RF module by connecting Dout pin of HT12E to the data pin ‘D’ of RF transmitter. Fig. 2. Timing diagram [2] D. Scan Codes The keyboard sends the different scan codes for each different key pressed Table III. The scan code sent is independent of the condition that whether the caps are on or off, i.e. same scan code will be sent when the caps are on and when caps are off. For example the key ‘A’ sends the ‘1C’ (Hex), key ‘Q’ sends the ‘15’ (hex), F1 key sends the ‘05’ (hex), etc. More characters or the longer scan codes are generated by some keys like PRT SCR, PAUSE, etc. The codes sent by the keyboard are HEX codes. TABLE II. SCAN CODE Fig. 4. HT12E and RF module interconnections [10] © 2013 ACEEE DOI: 01.IJRTET.8.2. 559 79
  • 3. Letter Paper Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013 IV. RECEIVER SECTION running hand. A theoretical model presents the upper and lower-bound text-entry rates on QWERTY keyboard [8]. The result is given in tabular form in Figure7.Considering 3475 peoples typing speed the statistics says that mean of speed of typing is 40 words per minute (WPM), median is 38 WPM and mode is 31 WPM with standard deviation of + 16.7 WPM from the median [9]. The receiving section is on display side which includes the RF receiver module, HT12D, microcontroller, and display Figure5. Fig. 5. Reciever end The wireless data is received by the RF module serially and the HT12D receives the serial data and give the parallel data output to the controller after decoding it. Fig. 8. Typing speed (statistically)[8] With time calculation the response of human to press key board key and delay in pressing keyboard key is in range of millisecond where the microprocessor response time is in the range of microseconds Figure8. With due consideration we can say that there will not be time issue in such case. However the display response time is one factor that depends on display type, colour and light condition and can be adjusted by changing microprocessor program using delays as per the practical situation. A. HT12D HT12D is a decoder IC which is capable of decoding information which consists of 8 address bits and 4 data bits. HT12D has operates at voltage specified as 2.4V~12V, and provides low standby current. Address pin A0~A7 are the Input pins for address externally set to +5V or left open as per the address specified on transmitter side. D8~D11 are Output data pins, Din is the Serial data input pin, VT is for the valid transmission, must be active high Figure6. The input data to decoder is serial and the output data is parallel. Data pin ‘D’ of RF receiver module is connected to Din pin of HD12D. VI. SIMULATION RESULT AND T EST OF HARDWIRED MODEL Fig. 6. RF and the HD12D interconnections [10] Fig. 9. Simulation result on Proteus V. TYPING SPEED AND DISPLAY RESPONSE A consideration of typing speed is important where it is a need to get the display content changed while typing in Fig. 10. Hardwired circuit Fig. 7. Theoretical typing speed [8] © 2013 ACEEE DOI: 01.IJRTET.8.2.559 80
  • 4. Letter Paper Int. J. on Recent Trends in Engineering and Technology, Vol. 8, No. 2, Jan 2013 Simulation of the circuit is performed on PROTEUS tool. The simulation result for display on LED was good. The hardwired circuit performance was as per the simulation result of PROTEUS Figure9. The program written for alphabets, numerals and special symbols were displayed on LED according to the key is pressed on keyboard. The range or transmitter and receiver are dependent on antenna quality with the antenna used transmitter and receiver communication was unaffected up to 90 meter range. Copyright 1998-2010, Adam Chapweske. Retrieved from http:/ /www.Computer-Engineering.org [3] Celik, C. (2004). Using PS/2 keyboards in embedded systems. In Istanbul-Turkey: Lima Endustriyel Bilgisayar. Retrieved from www.lima.com.tr [4] Kadu, R. A., More, V. A., Chitte, P. P., Rana, J. G., & Bendre, M. R. (n.d.). Wireless control and monitoring of robotic arm (swords). International  Journal  of  Computer Technology  and Electronics Engineering (IJCTEE), 2(1), doi: ISSN 2249-6343 [5] Kymissis, J., Kendall, C., Paradiso, J., & Gershenfeld, N. (1998, August). Parasitic power harvesting in shoes. The second IEEE International conference on wearable computing. [6] Bhargavi, D. S., & Manjunath, S. (2011). Design of an intelligent combat robot for war fields.International Journal of Advanced Computer Science and Applications (IJACSA) , 2(8), 64-70. Retrieved from www.ijacsa.thesai.org [7] Piyare, R. K., & Singh, R. (2011, March). Wireless control of an automated guided vehicle. In Proceedings of the International MultiConference of Engineers and Computer Scientists. doi: ISSN: 2078-0966 [8] Soukoreff , R. W., & MacKenzie, I. S. (1995). Theoretical upper and lower bounds on typing speed using a stylus and soft keyboard . Behaviour & Information Technology, 14, 370379. [9] Ostrach, T. R. (1997). Typing speed: How fast is average : 4,000 typing scores statistically analyzed and interpreted. In Orlando, FL: Five Star Staffing. [10] Sheth, V. J., & Suryawanshi, P. V. On the Design and Development of a Motion Control System using Accelerometer and RF Communication. CONCLUSION Both LCD and LED array are used as display to test the transmitter and receiver circuit working Figure10. It was found that working model was performing well within the practical distance range of 60-90 meter between transmitter and receiver, which depends on antenna attached with transmitter and receiver and the obstructions. REFERENCES [1] Segalowitz, S. J., & Graves , R. E. (1990). “Instrumentation and Technique”, Suitability of the IBM XT, AT and PS/2 keyboard, mouse, and game port as response device in reaction time paradigms . Behavioural Research Methods, Instruments & computers ,22(3), 283-289. [2] Chapweske, A. (2003).The PS/2 mouse/keyboard protocol. © 2013 ACEEE DOI: 01.IJRTET.8.2. 559 81