A outline of what's in the test.

The test will be in our normal classroom on Wednesday 10th June at 10:14am

There will be a picture of an Arduino like this below and you'll annotate it with text and arrows. You may be asked to identify a crystal, capacitor, resistor, LED or voltage regulator too.

There will be one of the two pages from the Atmel mega 328 family's data pdf. You'll be required to comment on some of the functions in the page below and most of the features in the very front page.







There will be questions about a schematic involving the Arduino like the one below.

There's a clearer copy of this in a pdf on our Moodle page.

Test Information

There will be a theory test on Thursday 10 June. It will be closed book and you must complete it in 1 hour and 45 minutes. We will discuss some of the items in the test on the previous class.

There will be a question on the main parts of the Arduino. See the labelled diagram above. This is not exactly the same as our Arduino but, apart from the DIL processor and colour, is pretty close.

There will be a question on the page above called The Front Page of the Mega328. You will be expected to write a sentence explaining some of the features listed. 

There will be questions on the functions diagram of the Mega328. You will be given a copy of this diagram and be expected to write a short paragraph on up to three blocks.

There will be a question about the Arduino schematic diagram above or similar.

Also there's buggy program. A program will be given to you with errors in it. You will have to identify the errors. Mostly syntax violations.

A problem to do with sampling real world inputs will be given and you will be asked how you would respond to this using the Arduino.

You will be asked to write a simple assembly language program. You will be asked to write a program in Arduino C.

There may be other questions but only on items we have studied in class including serial buses, pin outs of the Arduino and the mega328p, voltage dividers, the stack and interrupts.

Please contact me about any problems. Good luck.

PeterB

Pulse width modulation

Good simulation vid

The Arduino page on analogWrite() here

You can use pwm to control higher voltages like here.

i2c Bus

Most popular of the serial buses. Uses one wire for clock and one wire for bidirectional data. Based on Phillips' iic network. Lots of chips use the i2c protocol.

Good short introduction here. Not Arduino based.

Using i2c to connect arduino to eeprom chip that holds 256k bits, here.

Interesting use of i2c OLED display.

SPI or i2c. Which one is ""better"?

Arduino descriptive diagram. DIL version of Rev 3

Arduino Uno Schematic

A good introduction to reading a schematic

The SPI bus

Fastest of the serial I/O on the Arduino.

A good tutorial on spi using a digital potentiometer chip here

A tutorial on the spi bus, more technical here

Two Arduino's connected via spi here. Code via link to github.

Using hex files from AVR studio to program Arduino

Programs needed are just AVR Studio and avrdude. I used AVR Studio version 4.14 and the avrdude that came with the Arduino suite.

Step 1. Write your program in assembler in AVR Studio, build then save the hex file.
Step 2. Go into the command prompt and invoke avrdude with the right switches.

I started with the usual Arduino C blink program, just to make sure I got the COM port right and to see the hardware was all working. Then did steps above.

Below are some relevant screen shots.

Blink for AVR Studio 4 assembler


.include "m328pdef.inc"


;Based on http://www.robertoinzerillo.com/wordpress/?p=5
;-----------------------------------------;
; FIRST WE'LL DEFINE SOME REGISTER TO USE ;
;-----------------------------------------;
.DEF A = R16   ;GENERAL PURPOSE ACCUMULATOR
.DEF I = R21   ;INDEXES FOR LOOP CONTROL

.ORG $0000

;-----------------------------------------;
; FIRST WE SETUP A STACK AREA THEN SET    ;
; DIRECTION BIT ON PORT-B FOR OUTPUT/SPKR ;
;-----------------------------------------;
START:
  LDI A,LOW(RAMEND)   ;SETUP STACK POINTER
  OUT SPL,A           ;SO CALLS TO SUBROUTINES
  LDI A,HIGH(RAMEND)  ;SETUP STACK POINTER
  OUT SPH,A           ;SO CALLS TO SUBROUTINES

  LDI A,0b1111_1111   ;SET ALL PORTB FOR OUTPUT
  OUT DDRB,A          ;WRITE 1s TO DIRECTN REGS

;--------------;
; MAIN ROUTINE ;
;--------------;
LEDONOFF:
  SER A
  OUT  PORTB,A
   RCALL DELAYLONG
  CLR A
  OUT PORTB,A
   RCALL DELAYLONG
  RJMP LEDONOFF


DELAYLONG:
; =============================
; Delaying approximately 1 sec at 8Mhz.
; This code has been created with  “AVR Delay Loop Generator V1.2?.
          ldi  R17, $48
WGLOOP0:  ldi  R18, $BC
WGLOOP1:  ldi  R19, $C4
WGLOOP2:  dec  R19
          brne WGLOOP2
          dec  R18
          brne WGLOOP1
          dec  R17
          brne WGLOOP0
; =============================
RET

Each AVR assembler instruction has its own help page with example.

Each op code has an explanation via the help screen

You can also go to the Atmel AVR assembler site and look at instruction like SER.

Port Input and Output

All AVR devices, like our Mega328, have ports. Usually they are a group of 8 pins that send or receive binary to or from the outside world.

There are three registers associated with each port.

1. The output register PORTX
2. The input register PINX
3. The data direction register DDRX.

For instance port B is made up of 8 pins PB0, PB1, PB2 ....PB7. It has three associated registers:

1. PORTB
2. PINB
3. DDRB

These registers live in the I/O register space just above the 32 general purpose registers.

Some good port pages:
Useful but about GCC.
Some good stuff here.

There are four sorts of memory on the avr devices like the mega328

Setting up the stack before using subroutines

The code for the above program is:

.include "m328pdef.inc"
start: ;set up the stack
ldi r16, low(RAMEND)
out SPL, r16
ldi r16, high(RAMEND)
out SPH, r16

nop

call below
nop

finish: rjmp finish
below:
ldi r17,$99
ret

The relevant part of the def.inc file the shows what RAMEND is for this processor is:

; ***** CPU REGISTER DEFINITIONS *****************************************
.def XH = r27
.def XL = r26
.def YH = r29
.def YL = r28
.def ZH = r31
.def ZL = r30



; ***** DATA MEMORY DECLARATIONS *****************************************
.equ FLASHEND = 0x3fff ; Note: Word address
.equ IOEND = 0x00ff
.equ SRAM_START = 0x0100
.equ SRAM_SIZE = 2048
.equ RAMEND = 0x08ff
.equ XRAMEND = 0x0000
.equ E2END = 0x03ff
.equ EEPROMEND = 0x03ff
.equ EEADRBITS = 10
#pragma AVRPART MEMORY PROG_FLASH 32768
#pragma AVRPART MEMORY EEPROM 1024
#pragma AVRPART MEMORY INT_SRAM SIZE 2048
#pragma AVRPART MEMORY INT_SRAM START_ADDR 0x100



; ***** BOOTLOADER DECLARATIONS ******************************************
.equ NRWW_START_ADDR = 0x3800
.equ NRWW_STOP_ADDR = 0x3fff
.equ RWW_START_ADDR = 0x0
.equ RWW_STOP_ADDR = 0x37ff
.equ PAGESIZE = 64
.equ FIRSTBOOTSTART = 0x3f00

Assembler delays

Using delays in AVR studio

Write a variation on the above program to produce any delay required for your project.

AVR Studio and assembly language.

You'll need to download AVR Studio 4.19 for further work on AVR assembly language.

RS232 protocol

The RS232 protocol has been around for many years now. There are various versions and we have to be aware that non-standard applications are used often. The main aspects are the sockets and plugs and the packet sending rules.

Think about the wearable project

The next project is about using an embedded system very close to a person. It could be on clothes, shoes or on something you carry or on an accessory like a coat, hat or belt. Some ideas below are given in links.

Links


http://atmelcorporation.wordpress.com/2014/01/23/wearables-to-create-personal-data-streams/?utm_campaign=January_2014_Newsletter.html&utm_medium=email&utm_source=Eloqua

Some Instructable wearable projects.

http://www.instructables.com/id/Despicable-Me-Minion-Costume-1/

http://learn.adafruit.com/light-activated-pixel-heart

New Zealand has a a strong wearable art movement.

http://www.nst.com.my/life-times/tech/top-picks-ground-breaking-wearable-gadgets-1.528292

http://realbusiness.co.uk/article/26128-7-of-the-best-tech-gadgets-from-londons-wearable-technology-show

http://www.pcadvisor.co.uk/news/google-android/3507296/android-wear-release-date-smartwatches/?cmpid=HTML-DN190314&olo=daily%20news

http://sensoree.com/

LDR, our first sensor

Some good code and information here.
Light dependent resistor circuit. See http://www.ladyada.net/learn/sensors/cds.html

Some voltage division images

We often want a sensor to send its signal using a changing voltage. For instance when the temperature is high we get a big voltage, and when the temperature is low we get a low voltage. Note that normally the input to an Arduino analog pin has to be between 0 and 5 volts.

Futurlec is a good site for buying Atmel ICs

Voltage division

Many sensors we use with the Arduino allow us to sense a changing signal, like light or heat, in terms of a changing voltage. We need to work out the approximate analog input value.

You have to identify all the parts of our Arduino

The Sparkfun Arduino Uno smd

Can you identify all the parts.

Mega 328 Pinout vrs Arduino Pinout

Using the serial monitor

Simple program that uses the serial monitor:

void setup() { 
 //Initialize serial and wait for port to open:
  Serial.begin(19200); 
}
void loop() {
  Serial.println("Hello world");
}  

Lots of ideas on Fritzing site

Look at the projects page of the Fritzing site.

Push that button

Check out this site: http://www.arduino.cc/en/Tutorial/Button

Then do the tasks associated with push buttons.

Arduino Analog Inputs

Most sensors are detected via a changing voltage that's fed into the analog inputs using voltage division.

 There are some good introductions to analog voltage on the Arduino including this one.

And here's the Arduino tutorial about the analog pins.

Running two LEDs

/*

Blink2

Turns on a LED on for half a second, then off for half a second, repeatedly. It also does the same to an off-board LED connected to pin 12 so that when one LED is on the other is off.

The circuit:

* LED connected from digital pin 13 to ground via resistor.

* second LED connected from digital pin 12 to ground via resistor. I used 330 ohms.

* Note: On most Arduino boards, there is already an LED on the board

connected to pin 13.

Created 1 June 2005

By David Cuartielles. Adapted by Peter Brook

based on an orginal by H. Barragan for the Wiring i/o board

*/

int ledPin = 13; // LED connected to digital pin 13

int redLedPin = 12; // LED connected to digital pin 13

int del =500;

// The setup() method runs once, when the sketch starts

void setup() {

// initialize the digital pin as an output:

pinMode(ledPin, OUTPUT);

pinMode(redLedPin, OUTPUT);

}

// the loop() method runs over and over again,

// as long as the Arduino has power

void loop()

{

digitalWrite(ledPin, HIGH); // set the LED on

digitalWrite(redLedPin, LOW); // set the LED on

delay(del); // wait

digitalWrite(ledPin, LOW); // set the LED off

digitalWrite(redLedPin, HIGH); // set the LED on

delay(del); // wait

}

Building your own Arduino

Building your own Arduino is possible and you learn a lot in the process.

For example this site shows you how to build an Uno for about $5.

Talk like a pirate day. An Arduino introduction.

Led powered pumpkin from Instructables.

The classic intro on "talk like a pirate day"

http://www.youtube.com/watch?v=PeScmRwzQho

Also: lots about LEDs:

http://www.youtube.com/watch?v=pMV2isNm8JU

More LEDs and good planning.

http://www.youtube.com/watch?v=NGRqWaIECm8

LED Pixel Matrix Project

http://www.youtube.com/watch?v=hEKEM6ZOsZE

A good intro via Jaycar (but slightly different Arduino)

Another Arduino introduction. This time for the Uno.

Also  an introduction the Chinese clone Arduinos. Cheap but don't help the Arduino community.

LED information

Good diagram of LED pinout

Some more LED information

Check list for first two weeks.

Make sure you have addressed the following topics.

Week one
Access class Moodle site.
Access class blog.
Created own blog.
Put blog URL into Moodle wiki.
Started tasks from class blog.
Purchased Arduino kit.
Unpacked kit and got default led flash after plug in.

Week two
Get Arduino IDE going.
Look at main Arduino site.
Checked pages on how to get started.
Found example programs in IDE.
Run famous Blink Program.
Did simple mods to Blink and ran them.
Understand structure of Arduino sketch.
Found the Arduino C language reference.
Installed kit's project software in examples.
Do blink sketch from kit book.
Download Fritzing.
Accessed specs for LED project.
Continued with blog tasks.

The booklet that should have come with the red Arduino kit carton

Find the contents here:

Tasks

List of Tasks. You have to respond to all of these in your blog.
Please number your tasks in your blog so they can be found easily.


1. Start your blog.

2. Edit the permissions in your blog so that just prjbrook@gmail.com is invited to see it.

3. Make sure you can access the Arduino environment. Find the Blink program in the examples and paste into your blog. Test that it compiles in the Arduino IDE but you don't have to send it to your Arduino yet.

4. What is the name of the Atmel microprocessor in your Arduino board? Insert the link to the large pdf from Atmel associated with this chip. Insert an image of the first page of this pdf. Finally insert a picture of the pin-out of this chip.

5. Find the forum associated with main Arduino site. Take a screen shot of something in the forum that interests you with a comment on what appeals to you.

6. Find a picture of your Arduino  publish it in your blog and label the main parts. You may need a special graphics program to do this. Add another interesting Arduino variation. You can see some on this page.

7. Put the url for your blog into the wiki in Moodle. Add some other contact details. If you wish your cell phone number to remain private that's OK too.

8. Check out the following sites. Insert a screen shot and a URL link into your blog. Small images or large ones are both OK .
The Arduino environment version 1.5 or (stop press) 1.6.
The Processing environment.
The Fritzing files.
Link to Blogger.
GNU gcc
Moodle
AVR Studio download. Latest version.
PDF of ATMega 328
PDF of specs of USB-to_serial chip. The one used in the Duemilanove.
Good pic of our arduino clone
The MindKits site.
One cool video on Youtube.
One other interesting internet resources. eg "Make" site or electonics sites.
The Nice Gear store in Timaru that sells good Arduinos.

9. Find 4 more Arduino LED related videos in Youtube, BlipTV etc. Put a link and a two-sentence review about each one in your blog. Be prepared to talk about one or more of them to the class.

10. Establish a sketchpad folder in the D Drive or in a USB pen or somewhere you can get to.

The next tasks will relate to programming your Arduino using the Blink program with variations. So you might like to get going on setting things up.

All programs from now on need their source code to be entered into your blog with comments. Make sure you comment the the top of your blog posting with the number of the task and enter too the task number as a //coment in your code.

11. Copy the famous Blink program to your blog and make sure you can run it on you Arduino.

12. Create a variation in timing and put your new program into your blog. Indicate with a comment what your change was.

13. Write a program that will have the LED mostly off. That is it only blips on once a second if you look closely.

14. Same as 13 but this time have your LED mostly on.

15. Repeat 14 with an external LED on a breadboard.

16. Copy the two LED program into your blog and run it.

17. Insert a variation so that the LEDs blink together.

18. Write a program so that one LED is blinking fast while the other blinks slowly.

18.1 (Look at analog pins.) Pin A0 will read any voltage value between 0 and 5 volts. Set up your Arduino board so that its circuit looks like the Fritzing diagram on this site. Run the program and make a change with a comment in your blog.

(Now looking at serial monitor.)

19. Copy the ASCII printing program from http://arduino.cc/en/Tutorial/ASCIITableand run it. A good background site is the lady ada serial tutorial.

20. Same as 19 but make some changes in formatting. Indicate your changes through a comment.

20.1 Have a look at this blog and run the following programs as they are set out in the blog then make some interesting chnages that you indicate with a comment and publish your versions in your blog.

20.11 Echo, echo.

20.12 Stage 2, delimiters.

20.13 Stage 3, Arduino maths.

20.14 Stage 4, simple transmission of a double.

20.15 Stage 4 again, Double, double.

20.16 Stage 5, analog read. (Very similar to 18.1 above.)

21. Randoms. Write a program to output random numbers between 0 and 100 to the serial terminal.

22. Write a program to output the throwing of a dice every second and display the number that comes up.

23. Same as 22 but display as well the number of sixes that you have thrown so far.

24. Same as 23 but speed it up and stop when you get to 25 sixes.

25. Same as 24 but don't display the dice numbers, rather say how many throws it takes to get to 100 sixes. Then start again each time you get to 100 sixes.

25A. Write a program that takes the output of the voltage between two resistors into an analog port pin for reading. This voltage will be between 0 and 5 volts. Output the number you get between 0 and 1023 to the screen. (Try different resisitors and predict what will happen.)

25B. Same as 25A but this time make one of the resistors a variable resisitor so that your output will change.

26. RS232 Check out this site  and others like it so you can write about 100 words in your blog on the protocol. Include in your text two pictures of pin-outs or relevant frames.

27. A very short talk to the class about an Arduino command that you can use in your programs. Check out the word allocated to you in the wiki part of our blog. Study the word and give a 2-3 slide presentation telling the class what the word does and give an example of the way it's used in Arduino code. Any other tips or relevant information should be presented. The talk should last about a minute.

28. Write a delay subroutine in avr assembler using AVR studio 4 that lasts fro exactly 50 milliseconds.Refer to a post above in this blog called assembler delays.

Welcome

Welcome to the 2015 Embedded class

Most of our work will come from tasks set on this blog and you will respond with your own work in your blog. For example you will have to write a short program to flash a LED early on the course. You get this going in the Arduino environment then transfer the code, and perhaps, pictures, links or movies onto your blog page that corresponds with the task. Please remember to put the task number somewhere in or near the title for easy marking purposes.

Sometimes extra information is given in our Moodle pages.