WEEK 6

ELECTRONIC DESIGN

WEEK ASSIGNMENTS:

Tasks for a week

Individual assignment:
Redraw the echo hello-world board
Add (at least) a button and LED (with current-limiting resistor)
Check the design rules, make it, and test it

Group assignment:
Use the test equipment in your lab to observe the operation of a microcontroller circuit board

Task:01 To make PCB board:

What is electronic design?

Electronic circuit design involves the selection and interconnection of physical devices in a variety of topologies to meet performance specifications, environmental requirements, power and cost budgets, operating life requirements, and other design constraints in agreement with an overall schedule.

Machine used:

Milling machine:Roland SRM-20

Software used:

Eagle

Arduino IDE

This week assignment content:

INDIVIDUAL ASSIGNMENTS:

Schematic Design.

PCB Design.

Mods Settings.

Milling.

Soldering.

Programming.

PROBLEMS:

Layer width small.

merged layer traces.

header pin problem

crystal traces short.

wrong connection of IC

Individual Assignments:

First I have to go through the Eagle software with the help of a youtube tutorial then I have downloaded eagle software version 9.6.2.

Schematic Design:

Create a new schematic diagram.

Downloading Library from previous student's archive.

How to add library in eagle software?

Steps:

first, you have to copy the library from the download folder and paste documents>eagle>libraries.

copy library address from documents folder then open eagle software.

go to the option>directories and paste the library address

then go to the menu>library>open manager library.

browse library from documents folder here library pasted.

and update all library from eagle software>menu bar>library option and update all library

then you should see the library by clicking add a part from the left toolbar.

To make a Schematic diagram:

Steps:

First I have added all components which are required from the fab library by clicking add part tool from the left side toolbar.

After adding all parts, route them using a Net tool from the left toolbar.

I have completed the schematic diagram of the hello echo board and then I have designed the actual board by shifting from the schematic to PCB and making a route of components.

Bill of material.

Incompelete Design:

First Attempt:

This is my first PCB design in which the width of the Layer is 10 mil it is a very small size because I did not have an idea then my local instructor is telling me about the layer size.

Second Attempt:

This is the second PCB design I can not found routing of the last components because the layer of the last components are intersected with each other.

Change width size of PCB layer before making rout of PCB components I never forget to change the width of PCB layer.

Go to the DRC option from the left tool bar and then go to the distance option and change the width size and drill hole size.

Change the width of some layers because these layers intersect with each other because of not much space between the IC pads.

When I have completed routing and generate rml file into fab modules then I have known about the layer intersection before I did not die of layer intersection.

Creating space between layers.

I can not be connecting the last trace of components.

I was trying and found another way to connect the last layer.

I did not want to connect a zero-ohm resistor to my circuit. But in the last, I have an idea in my mind to change the pin name of 2*3 pin header so this is the better way to avoid the zero-ohm resistor.

This is my final PCB diagram. After face some problems I am able to do this task.

To make png file steps:

Then to export the traces file, go to File menu > Export > Image.

Set a name for the file, change the resolution 2000 dpi(Dot Per Inch), and select Monochrome to make it a black and white image.

Then I have given the file to mods.cda.mit.edu and generate rml file to mill the board.

Board Problem:

My first design is not working because I have not set the dimension of the circuit border. Due to the border dimension, some layer is removed in my circuit.

I have mill another circuit.

I have completed my new circuit.

Test circuit continuity.

Component List.

connect ISP board to my hello eco board circuit.

Programming

Programming done using Fab ISP board (attiny45) with Arduino software IDE. Steps as following:

1- Connect my echo hello-world board and the Fab ISP board together both to my laptop using Female to Female header wires and USB cables.

2- Set Arduino Preferences by going to File top bar menu > Preferences > in the Additional Board Managers URLs paste this URL:

https://raw.githubusercontent.com/damellis/attiny/ide-1.6.x-boards-manager/package_damellis_attiny_index.json

3- From the Tools menu > Borad > Boards Manager.

4- Search for attiny and install it.

5- ATtiny microcontrollers should be shown in the boards menu.

6- Set the following:

7- Click on Burn Bootloader. When done, you should see this message “Done burning bootloader.”.

8- Upload a simple blinking LED code to my echo hello-world board.

9- You should see this message “Done uploading.”.

This is my final result.

Microcontroller:

I chose to make my own microcontroller after being inspired by Arduino and having hands-on experience with Atmel family processors and controllers. To do so, I used Atmega 328 microcontrollers and designed the PCB as shown in the photographs.

I began by designing an arduino microcontroller sketch, selecting components from the fab library first, and then finishing the arduino sketch diagram.