Sensing + LCD Displays

In this assignment you will use an environmental sensor and LCD display to create a responsive prototype.

You can use any of the air quality sensors we reviewed in class, or you can construct your own sensor from scratch. The only requirement is that your sensor reports on some condition in the environment (soil moisture, movement, pressure, conductivity, etc.)

Use an LCD display to output data from your sensor. The output displayed on the LCD should be clear to a non-expert (meaning, you are not simply printing numeric values read from your sensor). It should be clear from looking at the display what the environmental condition is and whether the sensor is reading high, low, or moderate values.

In your demo video, demonstrate a scenario where this sensor and display would be used in the real world.

Document your project on the class blog under the “sensors-displays” category. Include a photo or video, a diagram, and a brief description (2-3 sentences).

This assignment is worth 4 points, everyone in the group will get the same grade

1 point for using an environmental sensor
1 point for using an LCD display
1 point for clear documentation that includes a video and description of how you made your project
1 point if your prototype is fun/creative

Open-ended skills review

In this assignment, you use the skills we learned in class to create an open-ended project. Your project must somehow engage with a theme discussed during the Biodesign faculty presentations.

The Biodesign themes we’ve discussed so far include:

Kombucha, fashion, food science
Immune system, personal genetics, cancer
Sensing, public health
DIYbio, DIY incubator

Your project should engage with Biodesign by prototyping an idea or concept related to one of the above themes.

Your project should also demonstrate at least 2 of the techniques we learned so far (digital input, analog input, capacitive sensing, thermochromic actuation, LEDs, motors, buzzers, LCD display, soil sensor, etc.)

Document your project on the class blog under the “review” category. Include a photo or video, a diagram, and a brief description (2-3 sentences).

This assignment is worth 4 points, everyone in the group will get the same grade

2 points for creating a prototype that uses at least 2 of the techniques we learned in class
1 point for clear documentation that includes a video and description of how you made your project
1 point if your prototype engages with an idea from the Biodesign presentations

Midterm

You have 1.25hours (a class period) to make an interactive prototype with your group.

Here is what we learned in class so far:

  • basic switches
  • soft analog sensors
  • LEDs, motors, piezo buzzers
  • muscle wire & thermochromic actuation
  • capSense
  • laser cutter
  • how to use google

Use any materials to make anything. Post the results on the class blog under the “midterm” category.

This midterm is worth 4 points, everyone in the group will get the same grade

2 points for creating something interactive (upload code, video, and diagram)
1 point for explaining what you wanted to do and how/why what you did is different
1 point if your prototype is fun/creative

Transistors and thermal actuation

In this assignment, you will create a thermochromic system. You will use a transistor to activate either a peltier element, heating pad, or muscle wire to generate heat. You will also use thermochromic fabric or create thermochromic ink (using pigments that change color at different temperatures) to visualize the output of your system.

Muscle wire (flexinol) is an alloy that can be electrically driven: it contracts/expands (moves) when a current is applied across it. The muscle wire will heat up when a current is applied across it. Peltiers convert electric energy into a thermal energy. When current is applied across a peltier element, one side becomes cooler and the other side heats up.  A heating pad can be use to warm up a larger surface area.

The heating pad, peltier, and the muscle wire all draw more current than can be provided by the regular Arduino pins, so you will have to use a transistor to control current from the Arduino power pin (5v pin). Heating elements can be fun! Heating elements can also be dangerous.

Safety tips for using muscle wire:

  • DO NOT RUN CURRENT THROUGH THE WIRE FOR MORE THAN 2 SECONDS AT A TIME (1-2 seconds on, ~3 seconds off is ideal)
  • USE SUFFICIENTLY LONG PIECES OF MUSCLE WIRE (a short wire will get too hot)
  • DO NOT ATTACH THE WIRE TO EASILY FLAMMABLE MATERIALS (e.g., parchment paper)
  • NEVER LEAVE ACTUATED MUSCLE WIRE UNATTENDED

A transistor acts as a type of switch: when voltage is applied to its base, a larger current/voltage will flow from the collector to the emitter. In this assignment, you will use one of Arduino’s digital output pins to drive the transistor, and Arduino’s 5V power pin will act as an “external” power source.

Create a circuit and code that drives muscle wire using the TIP120 transistor. You can refer to this ITP transistor tutorial for more information on driving external power sources. You can also see this thermal blanket example.

In addition, you will combine thermochromic pigments with a paint base of your choice. The pigments provided with this class will loose their color at 86F. You can use them to creatively visualize the output of your thermal circuit. This is a cool little demo of thermochromic paint.

Your circuit should exhibit interesting thermal behavior, beyond simply heating up and cooling down. Your project must be interactive (use a switch or analog sensor to activate the thermochromic behavior). You must also use a while loop in your code. For instance, use a switch, capsense, or one of the analog sensors as input to control the wire; or think about generating a heating pattern that mimics organic behavior. For more creative ideas, check out the muscle wire crane tutorial. This video shows a bunch of neat interactive examples.

Document your project on the class blog under the “thermal” category. Include a photo or video, a diagram, and a brief description (2-3 sentences).

This assignment is worth 4 points
1 points for setting up your Arduino/transistor/muscle wire or peltier or heating pad circuit and not burning anything
1 point for a while loop in your code and interactive input (switch, sensor)
1 point for clear documentation that includes a description of how you made your project
1 point for using thermochromic fabric or paint to visualize your actuation

capSense and organic materials

In this assignment, you will play with organic materials as part of your Arduino circuit. You will also learn how to install and use external libraries.

Download and install Arduino’s capacitance sensing library. This library will enable you to measure the electronic capacitance of organic materials such as foods, plants, or the human body.

Create a circuit and code that measures and responds to the capacitance of organic materials. You can think about building a simple food sensor that recognizes different types of foods based on their electronic capacitance; you can create a circuit that responds to human touch; or you can use organic materials as intermediaries between the Arduino and the person (for instance, detecting when a person touches a plant).

Your project must have some sort of creative output, beyond just the Serial print! You can use Max to create sound or video feedback, or add LED’s, piezo, vibration, or muscle wire output.

Document your project on the class blog under the “capSense” category. Include a photo or video, a diagram, and a brief description (2-3 sentences).

To receive full credit for the project, your circuit should have an interesting organic component based on the capacitance of some organic material(s) such as foods, plants, vegetables or the human body.

This assignment is worth 4 points
2 points for creating an Arduino circuit and code for responding to the capacitance of organic materials
1 point for video documentation and a description of how you made your project
1 point if your capSense project is creative/fun
1 bonus point if you included a food science experiment (pickling, kombucha, cheese, solar dehydration) as part of this assignment

Handcrafting analog sensors

Using one of the techniques we learned in class, create an analog sensor. For instance, you might create a sliding potentiometer using conductive yarn and beads, a rotary potentiometer out of conductive fabric and felt, or a pressure sensor out of conductive thread and fabric. You can refer to the Handcrafting Sensors guide for more ideas.

Connect your sensor to an analog pin on the Arduino and use the AnalogRead function to process the input.  As an output for your sensor, use the AnalogWrite function to control an LED or buzzer with PWM. For instance, your circuit might respond to pressure, tilting, or stretching with variable brightness or sound. If you use light as your output, you must use a LilyPad LED (not the basic ones we’ve been using in class).

Document your project on the class blog under the “analog sensing” category. Include a photo or video, a diagram, and a brief description (2-3 sentences).

To receive full credit for this assignment, you must go beyond what we did in class. You must use an organic material in your project.

This assignment is worth 4 points
2 points for creating an Arduino circuit and code for processing input from an analog sensor and a PWM-controlled output (sound or light)
1 point for clear documentation that includes a description of how you made your project
1 point if your project includes an organic material and is fun/creative

Arduino soft switch

Sign up for wordpress and email piyum.fernando@asu.edu and kstace@asu.edu your username to be added to the blog.

Get the Arduino software installed on your computer. Follow this installation guide to set up USB/FTDI drivers if necessary. You may also need to install CH304 Drivers.

Make an Arduino circuit that responds to a switch by changing the behavior of at east two LED’s. Connect your switch to a digital pin on the Arduino.  Use the DigitalRead function to detect whether the switch is open or closed. Use at least two LED’s to respond to the state of the switch. You can refer to the Arduino button tutorial.

Document your project on the class blog under the “Arduino Switch” category. Include a photo or video, a diagram, and a brief description (2-3 sentences).

To receive full credit for this assignment, you must go beyond what we did in class. Your project must incorporate an organic material. You can also try using creative materials for a switch (conductive dough, saline solution, tin foil), embedding your circuit in a physical object (e.g., a food item, a plant, clothing, a kitchen utensil), or a space that people inhabit.

This assignment is worth 4 points
2 points for creating an Arduino circuit and code where 2 LED’s respond to a switch
1 point for clear documentation that includes a description of how you made your project
1 point if your switch idea includes an organic material and is fun/creative