Task

  1. Individual Assignment:redraw the echo hello-world board,
  2. add (at least) a button and LED (with current-limiting resistor)
  3. check the design rules, make it, and test it extra credit: simulate its operation
  4. Group Assignment:use the test equipment in your lab to observe the operation of a microcontroller circuit board

Indivisual Assignment

Eagle

This is a also existing week for me ,this week is about Electronic designing,so as usual our instructor Supriya and Suhas sir took review of what we have to do in this week and explained us the bassic terms of electronics like resistor,capacitors,ohms law,etc.I am already familiar with this terms still I refered very useful "PPT" ,then I started with basic pcb designing softwareEagle

Features of Eagle

Eagle can run on any operating systems like windows.Mac and on linux also

It requires less memory space anywhere from 50-200MB of disk space

This is a free/low cost software,or you can download educational licence for 3 years free.

It has best community support.


Download, Install, Run

Downloading the full version and after installing clicking the “Run as freeware” button will give us all we need. There's a three great tutorials on EAGLE from sparkfun: Install and Setup, Schematic, and Board Layout

Exploring the Control Panel

The first time you open up EAGLE, you should be presented with the Control Panel view.

Control Panel

You can explore the six separate trees in the control panel, which highlight separate functions of the software:

Libraries -- Libraries store parts, which are a combination of schematic symbol and PCB footprint. Libraries usually contain a group of related parts, e.g. the atmel.lbr stores a good amount of Atmel AVR devices, while the 74xx-us.lbr library has just about every TTL 74xx series IC there is.

Design Rules (DRU) -- Design rules are a set of rules your board design must meet before you can send it off to the fab house. In this tree you'll find DRU files, which are a a pre-defined set of rules.

User Language Programs (ULPs) -- ULPs are scripts written in EAGLE's User Language. They can be used to automate processes like generating bill of materials (bom.ulp), or importing a graphic (import-bmp.ulp).

Scripts (SCR) -- Script files can be used to customize the EAGLE user interface. In one click you can set the color scheme and assign key bindings.

CAM Jobs (CAM) -- CAM jobs can be opened up by the CAM processor to aid in the creation of gerber files. Projects -- This is where each of your projects are organized into a single project folder. Projects will include schematic, board design, and possibly gerber files.(Source internet)

After downloading the Eagle and overviewing the control panel the imp part is "add the library",for our Echo board we are using by default given libarary called fab.lbr

Eagle lib

Fab.lbr

a library with the components available in fablabs. To do so, first download fab.lbr to any folder. Then, open the add menu with Edit > Add. If the fab library is not in the list, then Open Library Manager. In this new prompt, browse for the fab.lbr, and then close the prompt. Now the fab library must be in the list

Eagle Fab

Designing

Now time to circuit design for that first, I understand the image provided by Neil image of the circuit on assignment page: then I identify the appropiate components and see how they are connected to the rest.And I have to add a button and a Led and resistor to my circuit.

Reference sch.

So,I decided I will add 3 resistor ,3 leds and 1pushbutton in my circuit.

The schematic

Now it's time to create the schematic in eagle. We just need to follow the board above and,I will add led,pushbutton and resistor.First we will calculate the resistor value that we will add

For calculation of resistance we will use

"Ohm's law"

V=IR → R=V∕I

Voltage (operation): 1.8V (red), 2.1V (green) Current (max): 10mA (we don't need to go constant full brightness and can operate it at ~30%) Input voltage of V=5V,then
R=5V∕0/10mA=500Ω

Components we are going to use

  • supply1/+5V
  • supply1/gnd
  • fab/attiny44-ssu
  • fab/resonator
  • fab/res-us1206fab
  • fab/cap-unpolarizedfab
  • fab/avrispsmd
  • fab/ftdi-smd-header
    • Enhancement:
  • fab/6mm_switch6mm_switch
  • led/ledsmt1206
    • after calculation of resistor value we will start with actual schematic
    • Creat new project from control panel,in project creat new schematic named it and open the schematic window

      • New project

      • identify the elements (names help) in the board
      • get that element from the fab library and place in the schematic
      • Edit > add prompts the add menu. You have to open the fab lib, and look for the component you need, and click Ok
      • VCC and GND are selected from supply1 lib
      • Place the component somewhere in the schematic. The component can later be moved/rotated
      • Press ESC once you are done placing one component
      • connect the different components according to the given board and the datasheets if needed.
      • Draw > Net to draw the connections between components
      • Give values to the components:
      • rightclick a component to show menu
      • value and insert the desired value

      SMD component

      The final result of schematic and after connecting the component will look like:

      SMD component



      Key concepts of schematic and board

      NET Tool:To use the NET tool, hover over the very end of a pin (as close as possible, zoom in if you have to), and left-click once to start a wire. Now a green line should be following your mouse cursor around. To terminate the net, left-click on either another pin or a net.

      Routing GIF

      The board(source sparkfun guide")
      • Capacitor (German: Kondensator)
      • Crystal (German: Quartz): oscillates (e.g. to keep time); resonator is similar
      • Current limiting/ballast/series resistor (German: Vorwiderstand)
        • Pull-up resistor: avoid infinite current when the power source goes to ground and we want to read the signal from a microcontroller, pull-down just inverts the logic
      • Ratʼs nest: criss-crossing wires before theyʼre routed when moving from schematic to layout Airwire: unrouted trace (yellow lines in EAGLE board view)
      • Design rule checking (DRC): e.g. width of and spacing in-between traces
      • Electronic design automation (EDA): advanced circuits, e.g. with billions of transistors, are designed programmatically with a hardware description language

      Once the schematic is ready, it's time to create the real traces. First, we need to press Generate/switch to board button to get the board. It is a representation of the board components joined by airwires.

      Before trace

      All the components have to be placed in the black mat on the right. Then, you need to manually create the routes that cannot overlap. For that, use:
      • Edit > move and Edit > rotate to position
      • Edit > Route to create routes from one component to another
        Once you select route, and click on one component, you get feedback on all the possible endings of the route as seen in the figure on the right
      • Edit > ripout to delete a route
      • Tools > ratsnest to reorganize airwires

      You should check the Default Rules, DRC , which will give feedback on possible problems. You can also define your own rules in the DRC prompt, as minimum clearance (space) between conductive elements. You can define new values and save those settings for later usage. Values defined are

      Minimum size set I kept is 0.006"


      DRC check

      After routing the component and DRC check,it's time to export our file ,we will simulate the board .

      then before exporting one more important step is"Layer Setting",for traced image I hide all layer except dimension and top layer then I export this board as a "png"image,and for outline trace I hide all layer,except bottom and dimension

      Simulate

      Layer setting

      Layer setting

      Export as images File > Export > Image, with correct whites and blacks. Note that:

      • for my settings, for the outline image, the background must be changed to white (Select white at Options > User interface> Layout)
      • for the outline, you need to see just the layer 46: milling
      • for the traces, you need to just see the layer 1: top
      • select monochrome
      • set resolution. In this occasion I set it to 1000dpi. UPDATE!

      Traced Image

      Layer setting

      Milling and Soldering

      For milling and soldering I did same process as for FABISP,

      Milled PCB

      Soldered PCB

      I added one jumper wire from reset pin to Push button because I forgot to connect it in design file,while programming I got it.


      Group assignment(testing of PCB)

      • 1.Multimeter

        while I am doing soldering simultaneouly I was checking continuty between nearby componets because still I am not that much used to smd soldering .
      • I used the multimeter again after soldering the components to check the same thing
      • In this case, I had an "issue" i.e. shortning of path ,I remove it by X-acto cause this was just a small track so don't milled it again.

      • 2.Osciloscope

        In our group assignment section we used "DSO"osciloscope for checking the wave behaviour of the components.
      • In this test we understand the osciloscope's parameter like chanels,autoset,frequency,different wave signals

      Osciloscope

      Group

      Programming

      I downloaded the hello.ftdi.44.echo.c and hello.ftdi.44.echo.c.make
      Then I followed the Programming guide

      Program Guide

      I used my programmer from assignment5 to program this week's board

      Fab ISP as programmer

      Then I open my folder with "Git bash",and followed the instruction given,for my windows10
        • 1.make-f hello.ftdi.44.echo.c.make
        ,after entering this command my make file convers .hex file then I got output as

          • make


          • 2.make-f hello.ftdi.44.echo.c.make program-usbtiny-fuses
          , I got output as

            • Fuse

            • 3.make-f hello.ftdi.44.echo.c.make program-usbtiny
            ,after entering this command

          Running the program

          After connecting the board to the computer with an FTDI cable, I checked which is the serial port assigned:I checked it's port set baut rate as 115200

          Driver

          Opening the session opens a command prompt. The hello program is an echo program: I started to press keys in the keyboard:

          Programmed board1

          Programmed board1

          Programmed board2

          Resources

          Difficulties

          • I stucked in eagle while routing,then I refered no.of you tube tutorials that how to route properly
          • I got difficulties while soldering sometimes it was dry solder so I have to fixed it.
          • I have little difficulties in programming that,I don't had python when I downloaded it 3.7.0 version still it won't works.

            • Programmed board2

          • then my friend Manoj Sahukar helped me to solved it he suggest that I have to download python version 2.7.xx,then I have to make path then my board works

          Learnings

          • From others experience: always check continuity with the board

          Tips

          • For routing, just start doing it! It gets easier as you go on with the job

          Summary

          • I have learnt to use eagle to design my board: create schematic, route the board
          • I have used the multimeter to check my board connections
          • I have used the oscilloscope for some basic testing
          • I have used my programmer from assignment 05, and it works (!!)

          Files

          Download files here

          Assignment 6 Assignment 8