Week 10 Today

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Week 10Today

1. Homework presentations and critique.
2. Review digital and analog inputs.
3. DIY - jumpers, soldering etc.

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Homework

• Those who did not show last week show
• Pushbutton and LED
• Light sensor and LED
• Serial input to Arduino software
• Either Knight Rider or Shooting Star
• Potentiometer
• New version of above with a control structure
  (below)
• This weeks assignments
• Multiple switch assignment - make a project that
  uses at least 2 for interesting outputs.
• Create project with two HOMEMADE switches.
• Create a cool creative piece using at least one
  photocell and one other sensor and two LEDs or
  other outputs. This should be more than just some
  lights on your board, it should feel more
  finished - like the eyes project. As a class
  well crit and vote on the best ones - theyll
  get an extra credit mark.Criteria creativity,
  function, ability to explain code, clarity of
  codeTHIS ONE MUST BE LIVE AND WORKING IN CLASS.

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• Review

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Arduino Sketch Structure

• Top of sketch
• Declare variables at top
• Initialize
• setup() run once at beginning, set pins
• Running
• loop() run repeatedly, after setup()
• Pins can be changed in loop() too, but
  conceptually easier in setup()

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Arduino Programming
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Arduino Programming
Known Good Configuration Rule 1 of
experimenting Before trying anything new, Get
back to a known working state Get your entire
edit-gtcompile-gtupload-gtrun working Even if it
becomes so second nature to you that you feel you
shouldnt need to, do it anyway. Especially when
mysterious problems arise, revert to a known state
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Digital Input
Switches make or break a connection Most inputs
youll use are variations on switches Fundamentall
y, theyre all like the simple knife switch
Knife Switch
Toggle Switch
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Digital Input
Switches make or break a connection But Arduino
wants to see a voltage Specifically, a HIGH (5
volts) or a LOW (0 volts)
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Analog Inputs
Many states, not just two (HIGH/LOW) Arduino has
six ADC inputs (ADC Analog to Digital
Converter) Reads voltage between 0 to 5 volts
Resolution is 10-bit (1024 states) You used
this for the Potentiometer Homework exercise
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An Analog Sensor
Photocell, photoresistor, light-dependent
resistor A variable resistor ANALOG Brighter
light lower resistance Photocells have range
approx. 0-10k schematic symbol
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Reading Diagrams
Analog Sensor w/o Arduino shown Power Photocell C
ommon Join Arduino pin (Analog pin
0) Resistor Ground
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Reading Diagrams
Switch w/Arduino Power LED Arduino pin (Digital
pins) Ground Resistor Switch
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• Break, 10 minutes.

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Do It Yourself!
The exciting part of all this is that you can
make almost anything. If you are careful,
thoughtful, and test, retest, and document your
work.
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Doing It Yourself
Making Jumper Wires strip off about 1/2 of
insulation Can use wire strippers, cutters, or
fingers Can be a pain.. so often use pre-cut
wires to save time but they do cost more.
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Doing It Yourself
The End Result ready to go in the Breadboard
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Doing It Yourself

• Soldering
• Permanent connections
• When inputs and outputs need to be further away
  from the breadboard
• Demonstration
• Be careful not to overheat
• Watch for good connections
• Protect solder joints with hot glue when they are
  likely to be delicate or subject to stress
• Ventilation is good if you are doing a lot of it

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Talking to the computer
Communicating with Others Arduino can use same
USB cable for programming and to talk with
computers Talking to other devices uses the
Serial commands Serial.begin() prepare to
use serial Serial.print() send data to
computer Serial.read() read data from
computer Can talk to not just computers. Most
things more complex than simple sensors/actuators
speak serial.
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Talking to the computer
Watch the TX/RX LEDS TX sending to PC RX
receiving from PC Used when programming or
communicating
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Talking to the computer

• serial_hello_world
• Send Hello world! to your computer (and blink
  LED)
• Click on Serial Monitor to see output
• Watch TX LED compared to pin13 LED
• Assgn 1
• Do this. Get it working and save it.

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Telling Arduino what to do
serial_read_basic (get from examples) In
Serial Monitor type H, press Send Watch pin
13 LED blink once Notice how you might not always
read something, thus the -1 check. Assign
2 Modify to print hello world after it
receives something, but before it checks for
H. This way you can verify its actually
receiving something.
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Cool! Now what?
Now its your turn! Assgn 3 Add other outputs
onto your board. Use different key commands to
trigger them. Assgn 4 Get data in from an
analog sensor and print it out in at least 3
formats. (hint http//www.arduino.cc/en/Serial/Pr
intln) Assgn 5 Add other responses on the
screen and have different sensors trigger them.
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Homework

• Complete and post your work (description of
  project, photo of it, plus code)
• Assgn 1
• Get basic serial communication working.
• Assgn 2
• Modify to print hello world after it receives
  something, but before it checks for H. This way
  you can verify its actually receiving something.
  
• Assgn 3
• Add other outputs onto your board. Use different
  key commands to trigger them.
• Assgn 4
• Get data in from an analog sensor and print it
  out in at least 3 formats. (hint
  http//www.arduino.cc/en/Serial/Println)
• Assgn 5
• Add other responses on the screen and have
  different sensors trigger them.