PCB Design Method and Software

June 9, 2008

Method:

How to make PCBs with a laser printer

First thing to do is make a schematic in any Layout editor. Once you have done this you can then design the layout using layout editor too. Making schematic first helps because Layout editor will show you clearly if make any mistakes with the PCB.

Here is an example

Print it out onto some semi glossy photo paper. Be sure to select “solid black” in the Layout editor printing preferences and also unselect silk screen layers so that you only see pads and traces:

Then quickly take this paper, cut out your design and place it face down onto some blank PCB board. Then use an iron and press the design on to the board. Use A LOT of pressure and ensure all parts of the design make good contact with the blank PCB. Keep it pressed for at least 5 mins. I have found that having steam on/off makes no difference.

Then take your blank PCB with the design stuck on to it and soak it in soapy water for about 20 mins to loosen the paper.

Then CAREFULLY remove the paper. Be sure not to remove any of the black ink traces beceause these are what stops the acid in the etching process. I use a kind of rubbing motion to remove the paper. Keep it wet all the time so that it seoarates easily from the copper board.

Done and ready for etching:

Get some etchant and just follow the instructions for the dilution level. I just use a noral ceremic or glass bowel. Ghetto style.

Add boiling water from a jug:

And slowly swirl or rock the bowl around. The liquid must be always moving over the copper board to get it to etch properly.

Done!

Now scrub the black ink off the PCB and voila, you have a custom designed PCB:

Then all you need to do is drill out the holes and start mounting the components:

It will take maybe a couple of tries to get the hang of it but once you’ve got it you can produce perfect PCBs everytime.

Tips for making PCBs: www.expresspcb.com/ExpressPCBHtm/Tips.htm

Another guide like this: http://homepage.tinet.ie/~ei9gq/pcb.html

Note:

  • You can’t do it with Inkjet printers, the ink doesn’t stick.
  • OKI LED and regular laser printers work well.
  • I have only used matt photo paper and have always had perfect results, although glossy would probably work too.
  • Once the design is stuck to the PCB put a blank piece of paper over the design and then rub and twist the iron while pressing the print on the PCB. This gives better coverage and makes sure it sticks on all parts of the PCB.

Here is some pics of another design





SOFTWARE:

This is a good free PCB design software using which you can prepare professional looking pcb’s

to download use this link http://www.diptrace.com/download.php

download software with the libraries they contain most of the commonly used IC’s

It includes:

  • PCB Layout — PCB design with an easy to use manual routing tools, auto-router and auto-placer.

  • Schematic — Schematic Capture and export to PCB or Spice.

  • Pattern Editor — allows you to create part footprints.

  • Component Editor — allows you to draw parts and make components

OR

you can download PCB123 from “http://www.pcb123.com/”.

NOTE: I recommend using diptrace as it can prepare single sided pcb’s which PCB123 cannot do in free version.


A Good Site About Line Follower

May 15, 2008

Guys check this out. Other things are normal but the two videos in the end which show the difference when you apply only  Proportional control and when you apply Proportional and Differential control are worth watching.

This is the link to the page:

http://elm-chan.org/works/ltc/report.html


PHOENIX…..THE PERFECT LINE FOLLOWER

May 3, 2008

PHOENIX…..THE PERFECT LINE FOLLOWER

A SUCCESSFUL LINE FOLLOWER ROBOT…..A PROJECT MADE BY ADITYA, OMKAR, PRITAM & KETAN…..


Ultimate Line Follower

April 28, 2008

IF THIS DOESNT BLOW UR MIND NOTHING WILL..


MIN4A

April 28, 2008

Another video of this great mouse


Ultimate Micromouse

April 28, 2008

This is MIN4A, Second place in the Expert class was MIN4A, a micromouse developed by Ng Beng Kiat (Ngee Ann Polytechnic in Singapore)


Parallel port PIC programmer (Tested)

April 27, 2008

This is a simple parallel port PIC programmer taken from site http://www.members.aon.at/electronics/pic/picpgm

Download schematic here


Winners of micromouse @ techfest 08

April 27, 2008

Arjun secured third position in micromouse competition @ techfest 08

Team:
Anup kumbharikar
Sumedh deshpande
swapnil jariwala (jerry)


Micromouse side looking sensors by jerry.

April 27, 2008

Download this article in PDF form here

This article describes a analog IR sensor which gives output voltage

IR Distance sensor

Circuit is simple. This circuit uses differentiator to eliminate constant voltage component corresponding to ambient light. To be able to use this sensor it requires that transmitter be OFF normally and must be switched ON only when we want to sense. A transistor does the job of switch to make IR transmitter ON and OFF.

Hardware requirements:

ATmega16/32 with 8MHz crystal. Uart baud rate setting 19200 on hyperterminal. And proper ADCREF and AVCC connections.

Procedure to sense from programmers’ point of view:

1) Turn ON IR transmitter (PORTC3 =1)

2) Wait for 7uS (allow IR transmitter to glow completely)

3) Start ADC conversion.

4) Read ADC value.

5) Turn OFF IR LED (PORTC3=0)

This sensor value is then printed on hyperterminal screen through COM port using serial communication. I have set baudrate to 19200. you can change it if you find it necessary

Download program folder sensor.zip from http://www.swapniljariwala.co.nr/upload.php

Sensor.zip contains

1) main.c main C program

2) uart.h uart functions

3) makefile configuration file

Discuss your problems in the comment box provided.


Stepper motor driver using ULN2803

April 27, 2008

Download this article in PDF form here

Please read http://www.triindia.co.in/resources/?p=40 if you are handling the stepper motor for the first time.

stepper motor driver using 2803

Example describes stepper motor driver using ULN2803. In this example code two stepper motors are driven by a single timer. Code is written for ATmega16/32 running at 8MHz, for serial baudrate of 19200 and winavr platform.

Circuit description:

It is a simple unipolar drive. Circuit for a single stepper is shown same circuit is used for other stepper also. A B A’ B’ of first motor are connected to PORTB0-PORTB3. and other motor is connected to PORTD4-PORTD7.

Program description:

Include uart.h and makefile in your project folder and name your main program as main.c.

Stepper motors run by interrupt of Timer 0. Timer 0 is configured in CTC mode(refer datasheet) with pre-scalar of 1024. Every time interrupt is executed motors move by one step. Delay between the steps can be controlled by OCR0. To increase the speed of motor lower the value of OCR0 and do reverse to decrease the speed.

I use serial port of PC to configure speed and number of steps to rotate, this program runs without serial connection but motors will rotate only 100 steps each time it is switched ON. Connect a RS232 to TTL level converter like MAX 232 between TX and RX pin of uC and PC serial port.

Please read http://www.triindia.co.in/resources/?p=35 to configure your hyperterminal to be able to communicate with your robot through PC serial port.

Uart.h enables us to use C functions printf , scanf with controller. printf (“string”); writes specified string on hyperterminal screen and scanf can be used to take input from hyperterminal.

I have tested this circuit and program and it works fine but, There may be some bug introduced while writing this article so please post your comments to find the bug if any.

Downlaod stepper.zip from http://www.swapniljariwala.co.nr/upload.php

It contains main.c and uart.h.