Electronic designs typically contain a selection of highly complex functions—such
as processors, controllers, and memory—interfaced to each other by a plethora of
simple functions such as primitive logic gates. The simple interfacing functions
are often referred to as the glue logic because they “glue” everything together.
Group assignment
- Use the test equipment in your lab to observe the operation of a microcontroller circuit board (in minimum, check operating voltage on the board with multimeter or voltmeter and use oscilloscope to check noise of operating voltage and interpret a data signal)
- Document your work (in a group or individually)
Individual assignments
- Redraw one of the echo hello-world boards or something equivalent, add (at least) a button and LED (with current-limiting resistor) or equivalent input and output, check the design rules, make it, test it.
Find out the details of our common work al ZOI Here.
Oscilloscopes (or scopes) display voltage signals as waveforms,
visual representations of the variation of voltage over time. The signals are plotted on
a graph, which shows how the signal changes. The vertical (Y) access represents the
voltage magnitude and the horizontal (X) axis represents time.
The graph on an oscilloscope can reveal important information:
For this task we used
For more information about how to use a oscilloscope you can go to this website. Click Here.
A digital multimeter is a test tool used to measure two or more electrical values—principally voltage (volts), current (amps) and resistance (ohms). It is a standard diagnostic tool for technicians in the electrical/electronic industries.
For his task I used an auto-range digital multimeter which has multiple functions:
There are 3 steps to set the multimeter to test continuity:
I used the multimeter to check the traces on my board and the polarity of the leds I used.
It might be something obvious for many people, but I don't really know what a hello world is.
A "Hello, World!" program generally is a computer program that outputs or displays the message "Hello, World!". Such a program is very simple in most programming languages, and is often used to illustrate the basic syntax of a programming language. It is often the first program written by people learning to code. It can also be used as a sanity test to make sure that a computer language is correctly installed, and that the operator understands how to use it.
To download eagle and instal the fab component library you can go to my
pre fab page and fllow the instructions at the Electronics design section.
For this week assignment I designed a board based on
Adrian's Hello Train
from last year. I find this assignment pretty hard to do from scratch so I ratter follow
instrcutions until I understand all the concepts and processes involved.
I checked his BOM which has the following components and started from there since
I already understand how to insert and connect them on Eagle:
To start with the schematic I inserted the components from the fab library and checked the avaliability on the lab's inventory
to make sure I have all the components to built it later.
Found most of them but got really confused with the Attiny since I only found the Attiny 44, but on Adrian's
page he suggest the Attiny1614. I decided to go with it despite this condition. I wasn't really sure
that what I was doing would work but still wanted to do it to remind myself the process.
To upload the components write add or go to the "add component" icon located on the left bar.
With the components ready I wired them using labels to name them and add values to resitances.
Now is time to arrange the components on the board. Once on this window, all the components are placed in no
specific order. There are some things to have on mind for this step:
I enjoy arranging the components on the board. Once you are done you can check if there are errors. For this go to "errors" located on the left bar with an attention symbol!. Luckily for me there were no errors.
In case you have the traces made but for some reason you need to change the width, you can leave the traces layer on, select all of them, on the text bar write down change width 24 (or the width you need), press enter, right click on the drawing and change group.
Make sure all the layers are on, select them, in the text bar write move, press enter, right click, move group.
Eagle has an interesting option called DRC (design rule check) which warns you about clearance and design issues that could affect your board production.
In this case, based on the milling tool that will be used I set 0.4mm to make sure I wont have trouble later.
Also, if you press check, this window will pop up and some errors will be evident, in this case I had some trouble wiring, specially with double wires, errase the ones that are
not necessary or wire them again. Once this errors are cleared, the window will show 0 errors.
Here you can download the Design Rules Check File
For the traces: turn all the layers off and leave only the traces layer on. Go to file,
export, image. In the properties box mark monochrome and at least 1000dpi, in browse select were
you want to save this file.
For the border: same process as the traces, just leave the border layer on.
Eagle has the tools to generate its own file for the milling machine. First you have to dowload the UPL
avaliable
on this
and install it on the computer. Then press ULP and the next window will come out, fill the parameters using the
following parameteres:
The border is not possible to export on Eagle, so I used mods. It is importat on this point to
edit the png image to fill inside the border, otherwise mods does not recognize it.
It is necesarry to invert the colors in the contour image, for this I use pain, an easy and quick tool to achieve what I need.
The following pictures shows the parameter used on mods:
To make sure the files were right before milling I used the G-code simulator on line and found out
the scale of the border wasn't right.
Fixed it, by generating the files again, something was wrong when I changed the color of the contour using paint, but once I re-did this step itworked. Ready to go!
The machine used for this is one fabricated at the lab and hacked there.
The software used for millin is bCNC.
The mill used to engrave and cut the board was the same, a triangular 3mm mill.
The final result of my board. The edges are not very clean, this is because the mill is not sharp enough.
This can cause conductivity failures later, so it is necessary to sand it or pass a metal mesh to clean these threads. It is important to ensure that the contours of the tracks are free of any copper residue.
Something important I learned this week is that the micros have predetermined pins and functions.
In this case the pint out for the Attiny1614 is the following and it gave me a further understanding of this
component. Also my classmates recommended me to check the data sheet in case I have more doubths.
For further information about this micro you can visit this site where you will find the Attiny1614 data sheet
Most of the components were avaliable at the lab, still have to figure out what to do with the attiny 1614.
After searching at a couple of local vendors, finally found the Attiny1614. This is the final result of my board
For this process I needed some instructions to install the megattiny and make the UPDI to program my board. Found this really usefull site thanks to Diego
which has all the information needed step by step.
Getting started with the new Attiny chips and programming with the Arduino IDE
According to the web site there are two ways to install the megaTinyCore on the Arduino IDE:
In order to upload a code to the attiny, is needed to make a UPDI programmer and for this I am going to use an Arduino board and arduino IDE.
First, I have to transform the Arduino board to work as a UPD programmer. Then, I have to connect the attiny to the programmer to upload the code.
For this is necessary to use the UPDI Arduino sketch created by
ElTangas
The sketch converts ATmega328(p)-based Arduino’s, like the Arduino UNO, Nano, and Pro mini, into a UPDI programmer.
These are the steps to make the UPDI programmer:
Connect the ATiny to the Arduino as shown in the schematics below;
| Arduino | Attiny |
|---|---|
| GND | GND |
| 5V | VCC |
| D6 | UPDI |
Also add:
Follow the next steps:
//Adrián Torres - Fab Academy 2020 - Fab Lab León
//tiny1614 hello_train
//
//Original code:Neil Gershenfeld 12/8/19
// This work may be reproduced, modified, distributed,
// performed, and displayed for any purpose, but must
// acknowledge this project. Copyright is retained and
// must be preserved. The work is provided as is; no
// warranty is provided, and users accept all liability.
//
const int ledPin1 = 3;//first light
const int ledPin2 = 6;//white light
const int ledPin3 = 7;//white light
const int ledPin4 = 1;//red light
const int ledPin5 = 2;//red light
const int buttonPin = 0;// button pin
int buttonState = 0;//initial state of the button
int i = 0; //variable intensity led
void setup() { //declaration of inputs and outputs
pinMode(ledPin1, OUTPUT);
pinMode(ledPin2, OUTPUT);
pinMode(ledPin3, OUTPUT);
pinMode(ledPin4, OUTPUT);
pinMode(ledPin5, OUTPUT);
pinMode(buttonPin, INPUT);
}
void loop() {
buttonState = digitalRead(buttonPin);// we read the state of the button
if (buttonState == HIGH) { //if we press the button
digitalWrite(ledPin2, HIGH);
digitalWrite(ledPin3, HIGH);
delay(2000);
digitalWrite(ledPin4, HIGH);
digitalWrite(ledPin5, HIGH);
delay(2000);
digitalWrite(ledPin1, HIGH);
delay(5000);
}
else { //if we don't press the button
digitalWrite(ledPin1, LOW);
digitalWrite(ledPin2, LOW);
digitalWrite(ledPin3, LOW);
digitalWrite(ledPin4, LOW);
digitalWrite(ledPin5, LOW);
}
}
Based on Adrian's work I made some changes on the code, this is the result:
//Daniela Felix - Fab Academy 2021 - Fab Lab ZOI
//tiny1614
//
//Original code:Neil Gershenfeld 12/8/19
// This work may be reproduced, modified, distributed,
// performed, and displayed for any purpose, but must
// acknowledge this project. Copyright is retained and
// must be preserved. The work is provided as is; no
// warranty is provided, and users accept all liability.
//
const int ledPin1 = 3;//blue led
const int ledPin2 = 6;//red led
const int ledPin3 = 7;//red led
const int ledPin4 = 1;//blue led
const int ledPin5 = 2;//blue led
const int buttonPin = 0;// reset button
int buttonState = 0;//initial state of the button
int i = 0; //variable intensity led
void setup() { //declaration of inputs and outputs
pinMode(ledPin1, OUTPUT);
pinMode(ledPin2, OUTPUT);
pinMode(ledPin3, OUTPUT);
pinMode(ledPin4, OUTPUT);
pinMode(ledPin5, OUTPUT);
pinMode(buttonPin, INPUT);
}
void loop() {
buttonState = digitalRead(buttonPin);// we read the state of the button
if (buttonState == HIGH) { //if we press the button
digitalWrite(ledPin2, HIGH);
digitalWrite(ledPin3, HIGH);
delay(1000);
digitalWrite(ledPin4, HIGH);
digitalWrite(ledPin5, HIGH);
delay(1000);
digitalWrite(ledPin1, HIGH);
delay(1000);
digitalWrite(ledPin1, LOW);
delay(1000);
digitalWrite(ledPin4, LOW);
digitalWrite(ledPin5, LOW);
delay(1000);
digitalWrite(ledPin2, LOW);
digitalWrite(ledPin3, LOW);
delay(1000);
}
else { //if we don't press the button
digitalWrite(ledPin1, LOW);
digitalWrite(ledPin2, LOW);
digitalWrite(ledPin3, LOW);
digitalWrite(ledPin4, LOW);
digitalWrite(ledPin5, LOW);
}
}
This was the hardest week for me so far, lots of information, kind of frustrating at times, because there are many things I completely don't understand. But I'm going to follow Neil's advice, (this is something he said during class) "Don't look at this as a linear learning, better to go in spiral, learn something and come back to it later". That's what I'm gonna do, try to do my best every week, I know it's gonna take a bigger effort on this tasks, but i'll get it little by little. Fortunately my classmates and tutor have been patient explainig to me even te most basic stuff and open to share their knowledge and experience with me.