1
edit
Changes
Jump to navigation
Jump to search
→Activity 02: Digital Input (aka a button)
''(Generally, this workshop is offered at least once every two weeks on a rotating basis. Check the [http://designandbuildlab.com/?page_id=445/ Lab calendar] for up-to-date availability!)''
== Intro ==
This Workshop will introduce you to the world of microcontrollers: tiny computers that do a specific task. Effectively, what you'll be doing today is interfacing hardware and software together: you will write code which will interact with the outside world!
== Hardware Setup ==
You’ll be using a microcontroller today called the Teensy 3.2. As its name suggests, it’s pretty small! As such, the silkscreen (the text that appears on the faces of the printed circuit board, usually indicating things like pin labels) is minimal. In order to actually utilize the Teensy, you’ll need its [https://www.pjrc.com/teensy/card7a_rev1.pdf pinout]:
[[File:Teensy_3.2_3.1_pinout.png]]
=== Set up the Teensy on the breadboard ===
(add picture and description)
== Software setup ==
You're going to need two pieces of software to work with the microcontroller.
=== Download and install ===# Download and install the [https://www.arduino.cc/en/main/software Arduino IDE] on your operating system of choice. ''(Note: if you're using Windows, use the installer, not the app!)''# Download and install [https://www.pjrc.com/teensy/td_download.html Teensyduino], which adds Teensy support to the Arduino IDE. Just follow the prompts; you don’t need to install all the libraries, but if you ever want to work with Teensies in the future, it’s worth taking the time to install them now.
#Download and install the [https://www.arduino.cc/en/main/software Arduino IDE] on your operating system of choice. ''(Note: if you're using Windows, use the installer, not the app!)''#Download and install [https://www.pjrc.com/teensy/td_download.html Teensyduino], which adds Teensy support to the Arduino IDE. Just follow the prompts; you don’t need to install all the libraries, but if you ever want to work with Teensies in the future, it’s worth taking the time to install them now. === The which, the where, and the how ===
In order to get the Arduino IDE up and running with your board - regardless of which board it happens to be - you must answer for it three questions: the which, the where, and the how.
# Which board are you using?#* Navigate to ''Tools → Board'' and select ''Teensy 3.2 / 3.1''# Where is the board connected?#* Navigate to ''Tools → Port'' and:#** Windows: select ''COMX'', where ''X'' is the largest number (it should also say Teensy 3.2)#** OSX: select ''/dev/cu.usbmodemXXXXXX'', where ''XXXXXX'' is some number. This may not show up with Teensy.#** (You can see that neither of these operating systems handle hardware communication ports very elegantly.)# How are you programming the board? So far, you’ve used the mEDBG device for programming. Teensy won’t work with that - but it will work with the default programmer, the AVRISP mkII.#* Navigate to ''Tools → Programmer'' and select ''AVRISP mkII''.
== Activities ==
Each Activity in this Workshop will have a Hardware component and a Software component. It will be important to remember this, to begin to compartmentalize each task you must complete! Ultimately, this workshop will consist of two main objectives: how to control digital pins (both as inputs and outputs) and how to control an analog pins (both as inputs and 'outputs').
=== Activity 01: Digital output (aka 'Hello World' for hardware) ===
In this activity, you will use a pin on the microcontroller to blink an LED.
# Navigate to ''File → Examples → 01.Basics → Blink''.<br>The code which appears should look something like this:<br>[[File:code for teensy.png]]# Upload the code to your board using the button or CTRL+U. This is actually a compile and program. If you get any errors, ask for help. Assuming it has programmed correctly, you should now see the onboard LED blinking!# Fiddle with the delay times and reprogram to see how you can affect the speed of the LED blinking.# Connect an LED and a 220Ω resistor (just like in previous labs) to D9, and then change to code to reference this new LED’s pin.# Compile and Program to test.
'''NOTE: There is a button on the Teensy. This button does not do what you think it does. This button is a program button, meaning that when you press it, the device takes the most-recently compiled code and sticks it in its program memory. This is not a reset button!'''
=== Activity 02: Digital Input (aka a button) ===In this activity, you will use a button to control an LED - all through software. Leave the LED and 220Ω resistor connected to D9 like in the previous activity.
# Navigate to ''File → Examples → 02.Digital → Button''.# Connect a button to D2.# In the code, change the button pin to D2, and the LED pin to D9.#Make the following change to the code#: <code>pinMode(buttonPin, INPUT_PULLUP);</code># Compile and Program.# Modify the code so that when you press the button the LED turns on, and when you are not pressing the button, the LED turns off.
=== Activity 03: Analog Input (aka knobtwisting) ===
In this activity, you will use a knob to control the blinking speed of an LED - all through software.
# Navigate to ''File → Examples → 03.Analog → AnalogInput''.# Change the LED pin to D9. Additionally, change the analog input pin to A5.# Compile and Program, and turn the pot to change the speed at which the LED blinks!
There isn't a way (yet) to see ''exactly'' how long each of those delays is happening for. Let's change that. You're going to add some '''debugging''' functionality to your code - by incorporating the '''Serial Monitor'''.
# In the setup function, add the following line:#: <code>Serial.begin(9600);</code> <br> This initializes the Serial communications protocol.# Now, in loop, after you’ve read the value of the analog pin, add the following line:#: <code>Serial.println(sensorValue);</code> <br> (The method name reads as “print line”.)# Compile and program the code, and once it’s successful, open the Serial Monitor with CTRL+SHIFT+M or by going to ''Tools → Serial Monitor''. You should see values printing out on this screen; turn the potentiometer, and the value will change! This number is what is being used as the delay time (in ms) in the code.
'''ERROR: OH NO I CAN’T OPEN THE SERIAL MONITOR / OH NO I CAN’T PROGRAM ANYMORE.''' The Serial Monitor uses the same communication port as the Programmer - you can’t use both at the same time. Program the device, then open the Serial Monitor. If it’s still not working, check to make sure the IDE knows where the board is connected.
=== Activity 04: Analog 'Output' (aka breathe) ===
In this activity, you will program an LED to fade in and out. There is no input control.
# Navigate to ''File → Examples → 03.Analog → Fading''.# Compile and Program the code. your LED’s brightness should be fading up and down!
=== Activity 05: CHALLENGE ===
Using all your newly-acquired hardware and software prowess, create a device which directly controls the brightness of an LED with a knob.
