Microcontroller Based System Design

89c51 programmer

2011-03-08T23:39:00.005+05:30

A programmer for 89c51/52.
Use MAX 232 instead of DS232.
can be easily wired up on breadboard.
http://chaokhun.kmitl.ac.th/~kswichit/easy2/easy2.htm
The home page of the above link also list some interesting microcontroller based projects.
http://www.kmitl.ac.th/~kswichit/

Peripheral Component Interconnect

2007-12-07T14:57:00.000+05:30

The Peripheral Component Interconnect, or PCI Standard (in practice almost always shortened to PCI), specifies a computer bus for attaching peripheral devices to a computer motherboard.The PCI Bus is a high performance bus for interconnecting chips, expansion boards, and processor/memory subsystems.

Wiki article on PCI

Non-Return-to-Zero Inverted

2007-12-05T17:08:00.000+05:30

NRZI encoding is used for data transmission in the standard USB.
http://en.wikipedia.org/wiki/NRZI

EIA standards :RS232/422/485

2007-12-05T12:46:00.001+05:30

RS 232,422,485 -quick reference

RS 232 tutorial - A very informative webpage - Recommended

Selecting and Using RS-232, RS-422, and RS-485 Serial Data Standards
An application note from Maxim semiconductors.Includes connection firures for RS232.422,485 and specifications

Dallas Semiconductor application note on RS232 - simple

RS422/485 application note

Comparing Bus Solutions

2007-12-05T12:41:00.000+05:30

Texas Instruments Application Report "Comparing Bus Solutions" February 2004, Texas Instruments,

USB On-The-Go

2007-12-02T14:04:00.000+05:30

Every USB communications is between a host and a device. Devices can't communicate with each other directly. The On-The-Go supplement to the USB specification defines a new type of device that can function as both a device and as a scaled-back host (but not both at the same time). When functioning as a device, the On-The-Go device can communicate with a PC or other USB host. When functioning as a host, the device can connect to USB peripherals.

Universal Serial Bus

2007-12-02T13:39:00.000+05:30

Switch debouncing

2007-11-27T13:04:00.000+05:30

Switches can do some really odd things. Most engineers learn this dirty little secret soon after connecting a switch or a relay to a digital system. Switches don't make and break cleanly on the time scales of digital systems. Instead, a typical switch makes multiple transitions during the tens of milliseconds required to open or close, due to effects that include age, operating inertia, mechanical design, and the microscopic condition of the switch-contact surfaces. Commonly called "switch bounce," this behavior is an inescapable fact of life.

- application note 287 :Switch Bounce and Other Dirty Little Secrets,Maxim semiconductors

some resources--

Serial v/s Parallel transmission - which is better?

2007-11-26T11:42:00.000+05:30

Serial v/s Parallel transmission - which is better?

see this wiki article .....

http://en.wikibooks.org/wiki/Communication_Systems/Parallel_vs_Serial

a round up of microcontroller interfacing techniques

2007-11-25T23:33:00.000+05:30

Micro-controllers are useful to the extent that they communicate with other devices, such as sensors, motors, switches, keypads, displays, memory and even other micro-controllers.Many interface methods have been developed over the years to solve the complex problem of balancing circuit design criteria such as features, cost, size, weight, power consumption,reliability, availability, manufacturability.

The following document is a summary of some of these interfacing techniques
http://www.bipom.com/applications/micro_interfacing.pdf

Sorting algorithm animation

2007-11-25T15:21:00.000+05:30

Sorting algorithms:

We all know that Quicksort is one of the fastest algorithms for sorting. It's not often, however, that we get a chance to see exactly how fast Quicksort really is. The following link will lead you to applets chart the progress of several common sorting algorithms namely Bubblesort , Insertionsort , Quicksort and Select sort

sorting algorithm animation

wiki wiki ??

2007-11-25T14:40:00.000+05:30

Wiki Wiki is a reduplication of wiki, a Hawaiian-language word for fast. The word "wiki" (/wiːkiː wiːkiː/) is a shorter form of wiki wiki. WikiWikiWeb was the first site to be called a wiki., Ward Cunningham started developing WikiWikiWeb in 1994, and installed it on Internet domain c2.com on March 25, 1995. It was named by Cunningham, who remembered a Honolulu International Airport counter employee telling him to take the so-called "Wiki Wiki" Chance RT-52 shuttle bus line that runs between the airport's terminals. According to Cunningham, "I chose wiki-wiki as an alliterative substitute for 'quick' and thereby avoided naming this stuff quick-web."

http://en.wikipedia.org/wiki/Wiki

I2C Bus

2007-11-25T14:18:00.000+05:30

Almost 20 years ago the I2C bus was designed by Philips to allow easy communication between c omponents which reside on the same circuit board. Philips Semiconductors migrated to NXP in 2006.

The name I2C translates into "Inter IC". The original communication speed was defined with a maximum of 100 kbit per second and many applications don't require faster transmissions. For those that do there is a 400 kbit and - since 1998 - a high speed 3.4 Mbit option available.

Meanwhile I2C is not only used on single boards, but also to connect components which are linked via cable. Simplicity and flexibility are key characteristics that make this bus especially attractive for consumer and automotive electronics.

to know more about I2C Bus---

http://i2c-bus.org/

http://www.esacademy.com/faq/i2c/

The I2C-Bus and how to use it is a well-known document from Philips discussing the use of this bus in applications.

Wiki article on I2C bus

Reed Relays

2007-11-25T14:03:00.000+05:30

As a relay is a switch controlled by an electromagnet, so a reed relay is one or more reed switches controlled by an electromagnet. The contacts are of magnetic material; thus the electromagnet acts directly on them rather than requiring an armature to move them. Sealed in a long, narrow glass tube, the contacts are protected from corrosion, thus are ordinarily plated with silver rather than precious metals. The most common reed relays of the late 1930s through the 80s had two reed switches inserted into holes in the bobbin. Since the moving parts are small, reed relays are capable of faster switching than most others.

Reed Switches (wiki)
Reed Relay Applications

some interesting motor applications

2007-11-18T14:52:00.000+05:30

A document discussing some interesting applications of various types of motors

http://www.compumotor.com/catalog/cataloga/A72-A96.pdf

stepper motor basics

2007-11-18T14:28:00.000+05:30

A stepper motor is a brushless, synchronous electric motor that can divide a full rotation into a large number of steps, for example, 200 steps. When commutated electronically, the motor's position can be controlled precisely, without any feedback mechanism (see open loop control)

Some web resources on Stepper Motors:

Stepper motor Basics
Control of Stepping Motors - A Tutorial
A Wiki article on Stepper motors
Nice Animation of a stepping Motor : A German webpage.Please use the slider labelled as continuous to vary speed and run the animation.The stepping modes can also be changed.The type of winding can be selected from the top left corner of the animation

the microsoft way.............

2007-11-18T14:17:00.000+05:30

"Microsoft programs are generally bug-free. If you visit the Microsoft hotline, you'll literally have to wait weeks if not months until someone calls in with a bug in one of our programs. 99.99% of calls turn out to be user mistakes. I know not a single less irrelevant reason for an update than bugfixes. The reasons for updates are to present more new features."

-- Bill Gates on code stability, from Focus Magazine

DAC 0808 datasheet

2007-11-18T13:51:00.000+05:30

http://www.national.com/mpf/DA/DAC0808.html

ADC 0804 datasheet

2007-11-18T13:38:00.000+05:30

http://www.national.com/mpf/DC/ADC0804.html

Understanding DC Electrical Characteristics of Microcontrollers

2007-11-11T17:57:00.000+05:30

For the inexperienced designer, understanding the electrical characteristics presented in an integrated circuit data sheet can be confusing. If misinterpreted, a new design could prove disastrous. This tutorial is intended to demystify the steady state characteristics of the Maxim microcontroller product family.(but surely relevant for any microcontroller data sheet)
http://www.maxim-ic.com/appnotes.cfm/an_pk/1087

is 8051 a RISC or a CISC processor?

2007-11-09T23:23:00.000+05:30

8051 is a CISC () processor

"CISC (complex Instruction Set Computer), with all the possible adressing modes on the instructions"

although the actual number of instructions is quite small!

So, taking the words at face-value, it is quite "simple" relative to something "complex" like a Pentium;
It is also quite "simple" relative to something like the ARM - which is RISC!

"CISC" and "RISC" have to do with design philosophy rather than raw counts of numbers of instructions...

see the following discussion forum for more
http://www.keil.com/forum/docs/thread11113.asp

C v/s Assembly

2007-11-09T09:02:00.000+05:30

What are the merits and demerits of using C over assembly language for microcontroller programming,just see this discussion
http://www.keil.com/forum/docs/thread11112.asp#msg53554

RISC v/s CISC

2007-11-07T15:36:00.000+05:30

Source:
http://lobe.ibme.utoronto.ca/presentations/Microcontroller/index.htm

8051 ports

2007-11-07T15:00:00.000+05:30

The following thread sheds light on:

the status of 8051 port pins at power on/reset
what happens when a 1 is written to a port latch

http://www.keil.com/forum/docs/thread11092.asp#msg53474

http://www.8052.com/faqs.phtml?FAQ=120176

Keil C compiler online manual

2007-11-04T15:43:00.000+05:30

http://www.keil.com/support/man/docs/c51

von Neumann architecture and Harvard architecture

2007-11-04T15:40:00.000+05:30

The von Neumann architecture is a computer design model that uses a processing unit and a single separate storage structure to hold both instructions and data. It is named after mathematician and early computer scientist John von Neumann. Such a computer implements a universal Turing machine, and the common "referential model" of specifying sequential architectures, in contrast with parallel architectures. The term "stored-program computer" is generally used to mean a computer of this design, although as modern computers are usually of this type, the term has fallen into disuse.

http://en.wikipedia.org/wiki/Von_Neumann_architecture

Harvard architecture is a computer architecture with physically separate storage and signal pathways for instructions and data. The term originated from the Harvard Mark I relay-based computer, which stored instructions on punched tape (24 bits wide) and data in electro-mechanical counters (23 digits wide). These early machines had limited data storage, entirely contained within the data processing unit, and provided no access to the instruction storage as data, making loading and modifying programs an entirely offline process.

http://en.wikipedia.org/wiki/Harvard_architecture

The following link also provides some insight into the topic especially wrt ARM cores
http://www.arm.com/support/faqip/3738.html

8051 interfacing basics

2007-11-04T15:37:00.000+05:30

some websites on 8051 interfacing:
www.freewebs.com/maheshwankhede/index.html
www.edsim51.com/8051Notes/interfacing.html

Cross compiler

2007-01-14T13:34:00.000+05:30

A cross compiler is a compiler capable of creating executable code for a platform other than the one on which the cross compiler is run. Such a tool is handy when you want to compile code for a platform that you don't have access to, or because it is inconvenient or impossible to compile on that platform (as is the case with embedded systems, on which various kinds of microcontrollers run with a minimal amount of memory for their own purpose).

Know more about cross compilers from this wiki article

DS1302 - Trickle-Charge Timekeeping Chip

2007-01-05T23:25:00.000+05:30

DS1302 - Trickle-Charge Timekeeping Chip

The DS1302 trickle-charge timekeeping chip contains a real-time clock/calendar and 31 bytes of static RAM. It communicates with a microprocessor via a simple serial interface. The real-time clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with an AM/PM indicator.

DS1302 Datasheet

Supervisory Circuits Keep Your Microprocessor Under Control

2007-01-05T22:50:00.000+05:30

Maxim Semiconductor - APPLICATION NOTE 279

Supervisory Circuits Keep Your Microprocessor Under Control

Understand the value of a µP supervisor to ensure proper system operation during power-up, power-down, and brownout situations (undervoltage monitoring). In addition, provides information about overvoltage and windowed monitoring. Describes additional features such as manual reset, watchdog timer, battery backup, and chip enable gating. Discusses the need for multi-voltage monitoring.

Maxim Semiconductor - APPLICATION NOTE 279

Advantages of Using a MicroMonitor and a Simple Application Demonstrating the Use of a DS1232

2007-01-05T22:40:00.000+05:30

Maxim Semiconductor - APPLICATION NOTE 581

Advantages of Using a MicroMonitor and a Simple Application Demonstrating the Use of a DS1232
Discusses how the DS1232 can be used to MicroMonitor an 8051-based system. This supervisor circuit provides power-on-reset (POR), manual reset (push-button) input, a watchdog timer (strobe timer), and an early power-fail comparator. The reset threshold tolerance can set selected to monitor both 5% and 10% supply tolerance systems. In addition, a pin-selectable reset time-out delay is available.

To simplify the use of the device, a software execution program is included to show how the 8051 processor can be used in conjunction with the DS1232.

Maxim Semiconductor - APPLICATION NOTE 581

Watch Dog Timers

2006-12-31T19:57:00.000+05:30

A watchdog timer is a piece of hardware that can be used to automatically detect software anomalies and reset the processor if any occur. Generally speaking, a watchdog timer is based on a counter that counts down from some initial value to zero.

The embedded software selects the counter's initial value and periodically restarts it. If the counter ever reaches zero before the software restarts it, the software is presumed to be malfunctioning and the processor's reset signal is asserted. The processor (and the software it's running) will be restarted as if a human operator had cycled the power.

Introduction to watch dog timers
DS1232 WDT datasheet
(link updated 050107)

AT Keyboard

2006-12-31T19:34:00.000+05:30

The AT keyboard was a keyboard with 84 keys introduced with the IBM PC/AT computer. It succeeded the 83-key PC/XT keyboard and therefore did not have many of the features seen on modern keyboards such as arrow keys and dual ctrl and alt keys.

It was later replaced with the 101-key Enhanced keyboard. Nonetheless, "AT keyboard" remains a popular name for any keyboard that uses the 5-pin DIN connector. Many Enhanced keyboards used this, though it was eventually superseded by the PS/2 connector and many modern computers use Universal Serial Bus (USB) connectors instead.

Interfacing the AT Keyboard

Keyboard Scan Codes

IBM PC Parallel Port

2006-12-31T19:31:00.000+05:30

Interfacing the Parallel port : An excellent tutorial by Craig Peacock

How stuff works on Parallel Ports

ASCII codes

2006-12-28T20:38:00.000+05:30

ASCII stands for American Standard Code for Information Interchange. Computers can only understand numbers, so an ASCII code is the numerical representation of a character such as 'a' or '@' or an action of some sort.

ASCII Table

BCD to ASCII conversion

2006-12-28T20:31:00.000+05:30

The HEX equivalent of ASCII '0'(zero) is 30H.Thus to convert a packed BCD to ASCII we need to add 30H to the unpacked BCD

Packed BCD
34H
0011 0100
------------------------
Unpacked BCD
03H & 04H
0000 0011 0000 0100
---------------------------
ASCII
33H & 34 H
0011 0011 0011 0100

I2C Bus events

2006-12-18T01:26:00.000+05:30

I2C Bus events - a two page handout on I2C bus events

Build and load process for embedded application programs

2006-12-18T01:23:00.000+05:30

The following two page handout is about the build and load process for embedded application programs V/s desktop application programs'
download

http://www.nullmodem.com/

2006-12-17T20:04:00.000+05:30

An informative site on serial communication - nullmodem.com

RS 232,422,485

2006-12-17T19:52:00.000+05:30

PCI Bus

2006-12-17T19:42:00.000+05:30

PCI Bus -Wiki article

PCI Bus pin out

PCI - How Stuff works article

SPI Specification

2006-12-17T19:22:00.000+05:30

SPI Specification

Interfacing Serial EEPROMS with 8051

2006-12-17T19:00:00.000+05:30

Interfacing Serial EEPROMS with 8051

USB in a nut shell

2006-12-17T18:53:00.000+05:30

USB in a nut shell
The document provides amn insight into USB standard

Serial EEPROM 24C04 datasheet

2006-11-19T18:55:00.000+05:30

Serial EEPROM 24C04 datasheet

Basic Serial EEPROM Operation - Application note

2006-11-19T18:29:00.000+05:30

Basic Serial EEPROM Operation - Microchip Application note AN536

Motorola SPI Specifications, M68HC11 Reference Manual,

2006-11-19T18:20:00.000+05:30

Motorola SPI Specifications, M68HC11 Reference Manual
M68HC11 Technical Data
M68HC11 Reference guide

Stepper Motor basics Application notes

2006-11-19T18:15:00.000+05:30

An interesting application note on Stepper Motors

Serial Peripheral Interface

2006-11-19T18:10:00.000+05:30

Serial Peripheral Interface
A web pabe about SPI
PDF format of the webpage

THE L297 STEPPER MOTOR CONTROLLER

2006-11-12T20:22:00.000+05:30

THE L297 STEPPER MOTOR CONTROLLER

ULN 2003 - SEVEN DARLINGTON ARRAYS

2006-11-12T20:11:00.000+05:30

ULN 2003 - Seven Darlington Arrays - Datasheet (download location 1)
ULN 2003 - Seven Darlington Arrays - Datasheet (download location 2)

8255 Programmable Peripheral Interface

2006-11-11T19:34:00.000+05:30

8255 Programmable Peripheral Interface - Tutorial

8255 Programmable Peripheral Interface - Datasheet (download location 1)

Stepper Motor Basics

2006-11-11T19:25:00.000+05:30

Stepper Motor Basics (download location 1)
Stepper Motor Basics (download location 2)

Check out this Wiki article on Stepper motors

4N25: 6-Pin DIP Package Phototransistor Output Optocoupler

2006-11-05T21:12:00.000+05:30

4N25: 6-Pin DIP Package Phototransistor Output Optocoupler

download problems?

2006-11-05T21:08:00.000+05:30

In case of difficulty in downloading any files on the blog,you can download it from the email id, I have posted copy of the files there.

I2C Bus Specification

2006-11-05T21:06:00.000+05:30

I2C Bus Specification

Check out the blog archives for previous posts

2006-11-05T21:03:00.000+05:30

If you are not able to locate previous posts do check out the Archives section

DMX 512 interface

2006-11-05T20:53:00.000+05:30

The U.S.Institute of Theatre Technology (hence refered to as USITT) first developed the DMX512 protocol in 1986 as a standard interface between dimmers and consoles. It was a simple concept and was easily adoptable by all concerned. Since the first standard, some improvements was made in 1990 to accomodate some problems and it is now known as the USITT DMX512 (1990) standard.

check out this link to know more about DMX512 interface

MOC3020-M:6-Pin DIP 400V Random Phase Triac Driver Output Optocoupler

2006-11-05T20:45:00.000+05:30

MOC3020-M:6-Pin DIP 400V Random Phase Triac Driver Output Optocoupler

An introduction to 8051 development tools

2006-11-05T20:37:00.000+05:30

An introduction to 8051 development tools

Safety precautions for development tool:TRIAC + Microcontroller

2006-11-05T14:15:00.000+05:30

Safety precautions for development tool:TRIAC + Microcontroller

Interfacing the Densitron LCD to the 8051

2006-10-30T07:17:00.000+05:30

Interfacing the Densitron LCD to the 8051

ADC 0804 datasheet

2006-10-30T07:16:00.000+05:30

ADC 0804 datasheet

DAC 0808 datasheet

2006-10-29T18:20:00.000+05:30

DAC 0808 datasheet

Where The Mind is Without Fear

2006-10-14T20:24:00.000+05:30

Where The Mind is Without Fear

WHERE the mind is without fear and the head is held high
Where knowledge is free
Where the world has not been broken up into fragments
By narrow domestic walls
Where words come out from the depth of truth
Where tireless striving stretches its arms towards perfection
Where the clear stream of reason has not lost its way
Into the dreary desert sand of dead habit
Where the mind is led forward by thee
Into ever-widening thought and action
Into that heaven of freedom, my Father, let my country awake.: Rabindranath Tagore

Understanding Relay operation

2006-10-08T23:54:00.000+05:30

Understanding Relay operation

Build Your Own Microcontroller Projects

2006-09-24T20:50:00.000+05:30

Check out this site for some cool project ideas based on 8051 family.The site features a lowcost 89c51/89c2051 programmer with the flash programming software(easydownloader)
Build Your Own Microcontroller Projects

Intel Hex file format

2006-09-24T20:43:00.000+05:30

Check out his link for a quick idea about Intel Hex file format.
Intel Hex file format

Help required?

2006-09-24T20:37:00.000+05:30

In case of any difficulty in downloading the files provided on the blog ,you can find the copy of it in the email id
ece_2007@hotmail.com (access only to S7ECE, GEC Idukki Students)

Flash Programming methods

2006-09-24T20:32:00.000+05:30

This handout provides an overview of In System Programming of 89C51RDx2 devices. Do read this handout to better understand the 89c51 based trainer kit operation.
Flash Programming methods

Dual Port RAM

2006-09-17T23:03:00.000+05:30

Dual Port RAM

Sorting algorithm animation

2006-09-09T00:04:00.000+05:30

Sorting algorithms:

sorting algorithm animation

80C51 instruction set

2006-09-09T00:02:00.000+05:30

80C51 instruction set

8051 development tools

2006-09-08T09:08:00.000+05:30

This handout provides an overview about assemblers and 8051 development tools (RIDE and Keil Uvision)
8051 development tools

Topics for test 3

2006-08-20T18:45:00.000+05:30

test date:24/08/06, Thursday

8085 programming model- ie. the programmable registers in 8085
8085,8051 addressing modes:definition,egs
RAM memory space allocation in 8051,
Register bank select:PSW.4,PSW.5 bits
Stacks in 8085 and 8051 - PUSH and POP instruction
How does an 8085 based single board micrcocomputer(ie is a microprocessor trainer kit) work? - read the section from Ramesh S.Goankar's text (Section 3.6) and appendix B

Topics for test 2

2006-08-20T18:42:00.000+05:30

test date:22/08/06,Tuesday

Registers
Memory map
memory address decoding using NAND gates, Decoders
Tristate Devices
comparison b/w microprocessor & microcontroller
instruction cycle,machine cycle,T-state
Timing diagram of Memory read, opcode fetch,
control signals: RD-,WR-,IO/M-,ALE,EA-,RST,PSEN-