Electronics design

Update 06/07/21

Group assignment

use the test equipment in your lab to observe the operation of a microcontroller circuit board

Here you can check the electronics design grop assignment

individual sssignment

Redraw an echo hello-world board, add (at least) a button and LED (with current-limiting resistor) check the design rules, make it, and test it extra credit: simulate its operation

individual sssignment

for this assignemnt i used autodesk's eagle software here you can download an educative version you only have to create an educative account to redraw an echo-hello-world board based on the ATTiny44a chip here you can see the board i based my design once installed and decided which board to start from the process is pretty straight forward create a project that contains a scheme and a board file.

first i downloaded the libriaries following the instructive my instructor gave us.

eagle libraries

2.- then copy the file in my case was C:\Users\Luis.HernandezV\Documents\EAGLE\libraries

3.- Then restart eagle in case you already had it open

now it's time to place all the components and their respective conections so the software know what pad conect with wich pad

this is my final scheme

Now i clicked on the button to generate the board from the schematic file

this is the version that really made the final cut.

TIPS AND TRICKS

you have two choices to create your conections between components

you can create lines using comand net like in the picture above

Or you can create what eagle calls "implicit" lines using name in the command line and clicking on the line you want to conect.

to create an "implicit" conection you just have to give the same names to the lines you want to conect on the board file.

you can also give values to certain elements like resistors capaciors

you just need to type value on the command line and click on the component.

you can give names to components like the pullup resistor i used to the rst pin on the MCU like in the picture above

both of the components of the picture below serves the same function but the one that states "right component" at the bottom of the pic is easier to solder.

always search components that suits you necesities.

wrong component

right component

EAGLE already has a lot of compoents to choose aditionally you could use the FABcomponents (folowing the instructions to add libraries above)

but there are a lot of usefull component libraries in the library manager on eagle go to:

add part button/open library manager button/available tab/and add whatever you find interesting licking in the "use" button

this is my sch file

it's better to keep well organized your diagrams in case you need to redesign something.

or some one else is trying to use the file as an example.

I try to use this system in all of my eagle projects.

when you are ready click the "Generate/switch to board" button to create the brd file.

the first time you create the board file it will leave you a mess of component "wired" with yellow lines

this yellow lines are guides to show you where correspond in your sch file.

you have to create "routes" in order place copper in the pcb.

RED pads mean smd component and green ones means a through hole components

this yellow rectangle is the default pcb size. you can transfom it by clicking and draging the lines the lines.

file/import/DXF

also you can import you own DXF files and place them into the respective layers (outline in yellow and tsilk in gray)

right click on any line then propierties and you can change the width of only that selected line segment

i recomend to edit the DRC (design rules check) at the begining to avoid futures pain in the neck every time you open your board for the first time

type drc oin the command line to open the window like in the picture below.

the wider the line you made the easier is to solder. but also the wider the bigger the noise you get in your circuit (basically works like an antena).

choose a minimum clearance between routes that fits your machine capabilities. (i choose 10 mil for this brd)

Also if you have no idea of what you were doing like me. you can set the autorouter function to do all of the copper wires for you.

click on the auto router button on the right side of the screen.

remember to set te bottom layer to N/A like in the picture above. Otherwise you'll end doing a double sided pcb.

the biggest advice while working the auto router is thath you set the conection between essecial components first (like the mcu to the auxiliary pads, the sensors and the actuators)

then leave the autorouter set the routes to ground and voltage.

Also important to consider that you're doing single sided pcb so all of the components,routes and conection pads should fit nicely and have enough room

schematic on the echoboard using t45

board on the echoboard using t45

HERE you can download all of the files for this board (Vcarve,roland srm20- gcode ,sch & brd for eagle)

after milling and cutting it. Finally it was time to solder it so i'm going to list here the bill of materials

before soldering

bill of materials

1.- (1) ATTiny45

2.- (1) Tactile switch

3.- (1) 2X3 header

4.- (1) 1X6 Header

5.- (1) SMD LED green clear

6.- (2) resistor 10k ohm (one pullup for the button and one for the reset)

7.- (1) resistor 499 ohm (for the LED)

echoboard all soldered

after soldering all was time to program it

here i will post what i updated on this assignment if you can read this i messed up

picture of the echo dragon V1 this is the work i did during COVID-19 quarantine. if you can read this i messed up

and this is the echodragon v3 if you can read this i messed up

a screenshot on the schematic file of the echodragon v3 if you can read this i messed up

a screenshot on the board file of the echodragon v3 if you can read this i messed up

a picture of the pcb completily finishied this is a video of the whole process

it inlcudes.

the process of the toolpath generation (i give a lot of detail into electronics production week)
the soldering process (althoug a little boring i'm very proud of this little achivement)
uploading a blink sketch using a dev kit though.
testing the sketch i've made using the arduino IDE

please be gentle it involved a lot of effort for my self to edit the video on premiere pro.

at the time this video was recorded i didn't had an ISP of my own that's why i used a third party dev board

i repeated this sketch in embedded programming week using an ISP

this is a video of the fabrication including testing it with a blink

this is the text on the ino file.

this is a video of me testing the button sketch

obviously i had to compress it in order to push it to my repo but i will host it in here if you like to see it in detail.