hacdc-wiki/Old Pages/Electronics/AVR_Microcontroller_Class_2009.md

Syllabus, course material, homeworks, photos, etc from a previous
Introduction to Microcontrollers with AVR chips class can be found here.

For the current class, head on over to [AVR Microcontroller Class
2011](AVR_Microcontroller_Class_2011 "wikilink")

Also see (and contribute to) [Useful AVR
Links](Useful_AVR_Links "wikilink")

## Class 0: Introduction and Setup

What the AVRs are, what all the pins do, what they can do for you. Then
the toolchain: soldering together the programmer kits, getting the
software up and running.

Labs: building the kit and running a test LED flasher. (Almost all lab
today, little talk.)

**Resources**:

- Slides from class: [Media:class0.pdf](Media:class0.pdf "wikilink")
- ATmega48P Datasheets (get both): [ATmega48P Summary
  Datasheet](http://www.atmel.com/dyn/resources/prod_documents/8025S.pdf)
  and [The Long ATmega48P
  Datasheet](http://www.atmel.com/dyn/resources/prod_documents/doc8025.pdf)
- Download the software part of the toolchain: For Mac folks: [AVR Mac
  Pack](http://www.obdev.at/products/avrmacpack/index.html). For Windows
  folks: [WinAVR](http://winavr.sourceforge.net/) and the Atmel IDE [AVR
  Studio](http://www.atmel.com/dyn/products/tools_card.asp?tool_id=2725).
  For Ubuntu linux folks: "sudo apt-get install build-essential avr-libc
  binutils-avr gcc-avr avrdude"
- Programmer and mega48 pinouts:
  ![Image:FFVH7HBF5UO1JMR.MEDIUM.jpg](FFVH7HBF5UO1JMR.MEDIUM.jpg "Image:FFVH7HBF5UO1JMR.MEDIUM.jpg")
  <img src="Screenshot-ATmega48-88-168.png"
  title="Screenshot-ATmega48-88-168.png" width="320"
  alt="Screenshot-ATmega48-88-168.png" />

## Class 1: Programmer Hookup and Hello World LED Blinking

Lecture on how the programmer works -- simple serial interface basics.
Some basics on avrdude / GCC tools. Hook up the programming interface
wire-by-wire to the Mega48 chip and flash it with a simple program. Then
hook up an LED to the output port and watch it blink!

**Resources**

- [helloWorld.zip](http://elliotwilliams.org/avrclass/helloWorld.zip)

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- Class notes: [Media:class1.pdf](Media:class1.pdf "wikilink")

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- Wiring Diagram:
  <img src="wiring.png" title="wiring.png" width="520" alt="wiring.png" />

**Homeworks**

- Your kit has 10 resistors and 10 LEDs. If you want, you can solder
  them together to make \[AVR: LED Blinkenlights\].

<!-- -->

- If you didn't already, make labels for the signal wires. Think of an
  easy way to remember which go where (into the 6-pin or 10-pin header).
  And/or make permanent programmer "pigtails" by soldering the signal
  wires to a 2x3 header in the correct orientation (headers available in
  the HacDC hackersmart for pennies).

<!-- -->

- Play around with the delays in the LED_Demo.c code. Make the blinking
  faster or slower. Experiment with on time and off time.

## Class 2: Outputs: Bit Math, Cylon Eyes, and PWM Fading

How to make chips speak to the outside world, pin-by-pin. Enough C
bitwise-math operations to make it work. Pulse-width modulation.

Labs: Visualizing bytes, Cylon eyes, and dimming LED's. Extra credit:
cross-fading cylon eyes!

**Resources**

- [registers.zip](http://elliotwilliams.org/avrclass/registers.zip)
- [cylonEyes.zip](http://elliotwilliams.org/avrclass/cylonEyes.zip)
- [introPWM.zip](http://elliotwilliams.org/avrclass/introPWM.zip)
- Class notes: [Media:class2.pdf](Media:class2.pdf "wikilink")

**Homework**

- So you can make various lights blink and/or dim. Now what?
  Cross-fading cylon eyes? Patterns? Something groovy?

<!-- -->

- Note that you've got an 8-bit display if you're willing to read out
  numbers in binary. Useful for debugging later on, for sure. What else?
  Binary clock? Simple upcounter? Display "random" numbers?

<!-- -->

- If you could swing it around, you'd be on your way to a [POV
  toy](http://www.ladyada.net/make/minipov3/index.html).

## Class 3: Inputs: Buttons

Gather data from the world. The lecture ended up being just on digital
input.

Labs: One note organ [Media: class3.pdf](Media:_class3.pdf "wikilink")

## Class 4: Inputs: Debouncing and Analog-to-Digital conversion (ADC)

This class, we'll get to debouncing our button input, and reading in
continuous voltages

For more info on ADC stuff, see [this
note](http://www.avrfreaks.net/index.php?module=Freaks%20Files&func=viewFile&id=383&showinfo=1)

Labs: pushbutton organ, light-dependent theremin.

[Media: class4.pdf](Media:_class4.pdf "wikilink")
[Media:
debouncedMusicbox.zip](Media:_debouncedMusicbox.zip "wikilink")
[Media:
lightDependentTheremin.zip](Media:_lightDependentTheremin.zip "wikilink")

## Class 5: Serial I/O and Interrupts I

Laptop, meet AVR. AVR, laptop. Serial communication (plus serial-to-USB
cable) lets you connect your micro to about anything, including your
computer. Interrupts let the hardware (pins, serial port, timers, etc)
call run functions for you, with the main body of your code picking up
where you left off. Combine the two, and you can get pushbutton control
of an AVR from your laptop keyboard.

[Media: helloSerial.zip](Media:_helloSerial.zip "wikilink")
[Media: helloInterrupts.zip](Media:_helloInterrupts.zip "wikilink")
[Media: class5.pdf](Media:_class5.pdf "wikilink")
And as a bonus, if you run Python,
[serialScope.py](http://www.jerkpile.com/serialScope.py) provides a
helpful debugging tool and an example of how simple USB/Serial code can
be on the laptop side. Coupled with on-chip ADC, it's a (low speed,
sideways) serial oscilloscope. Otherwise, a handy debugging aide.

**Homework:** Take the scale.h from last class, and using input from
your laptop, make a full keyboard out of the AVR plus speaker. Or write
a ROT-13 device that takes your input and returns the encoded version.

## Class 6: Timers/Counters and Interrupts II

Timers/counters let you do precision things with time. Fix up that nasty
audio tone from the LDR theremin. Precise timing allows you to use LED's
as light sensors. It's also good for making quality analog output and
for directing servo motors. Interrupts + timers = deluxe PWM. Or give
your AVR a solid internal timebase. (You know you want to.) In this
class, we'll scratch the surface of what you can do with timers.

[Media: timerPWM.zip](Media:_timerPWM.zip "wikilink")

[Media:
timerPWM_ctc_hardware_toggle.c](Media:_timerPWM_ctc_hardware_toggle.c "wikilink")

## Extra Credit: I2C

Talked a bit about the I2C serial protocol -- a light-weight serial
multi-master bus using two wires (plus ground) and capable of addressing
127 different devices. Great for connecting to all sorts of peripherals.

Demoed an \$20 I2C 3-axis accelerometer using bare-minimum I2C code,
with none of the error-checking that the pro's would do. But it works a
charm. That's why it's called hacking, baby!

[Media: i2c_class.pdf](Media:_i2c_class.pdf "wikilink")

[Media: i2c_accelerometer.zip](Media:_i2c_accelerometer.zip "wikilink")

[Category:AVR_Class](Category:AVR_Class "wikilink")