# Schematics Workshop

## Intro and Goals of Workshop

• Chancey Fleet, Non-Visual Tech Ed and Design, Andrew Heiskell Braille and Talking Book Library
• Lauren Race, Accessibility Fellow, NYU Ability Project
• Claire Kearney-Volpe, Accessibility Teacher and Researcher, NYU
Today we’re going to use circuit descriptions and tactile schematics for hooking up circuits.

## Tour of Components and Symbols

### Schematics

Schematics are drawings of the relationships between components in an electronic device. They are blueprints used to build circuits.They use symbols that represent real life components. Real world examples of circuits range from a simple electrical fan to the complex circuitry of the laptop that you’re on.

We are going to hand out tactile graphics sheets with three columns:
• Column 1: the physical component glued onto the sheet
• Column 2: a tactile graphic of the component, scaled up to provide detail
• Column 3: the schematic symbol
These sheets will detail 7 components, in order of how we’ll cover them:
1. Ardunio Microcontroller
3. Piezo buzzer
4. Ground
5. USB cable for Voltage In
6. 220-ohm resistor
7. Jumper wires

Take 10 minutes to review and get familiar with the tactile graphics sheets. [After 10 minutes] Does anyone have questions before we move on to exploring our Arduino kits?

### Arduino Kits

Now we will explore our Arduino kits.

1. Locate each component.
2. In the largest compartment, you will find an Arduino in a box and a breadboard with the power and ground buses connected to each other with jumper wires. There are two smaller compartments. In one, there’s one USB cord. In the other, you will find four items:

• two jumper cables
• a 220-ohm resistor
• a piezo buzzer
• a paperclip.

3. Explore each component.
• ### Arduino

• Moving back to the larger compartment, locate the Arduino and take it out of its box.
• The Arduino is a rectangular shape. On one of the shorter sides, you should be able to locate a large, metal, cube. That is the USB port and we’ll need that later. Rotate the Arduino so the square USB port is on the upper right hand corner. That’s how we’ll orient the board today.
• If you feel along the long side of the Arduino, there are parallel plastic walls on either side. These are the rows of pin inputs.
• Unfold your paperclip and run the tip of it along the top of the walls. You should be able to feel that there are tiny pin holes on the top. These holes are your pin inputs.
• #### Left-side pins

• We count the pins on the left side from top to bottom.
• Starting at the top left of the Arduino board, and counting the pins down, we get the reset, power and ground pins (Since the Arudino is a computer and it has to have a power cord and a reset button). Let's use the paper clip to follow the description of each. The pins from the top-left going down are as follows:
1. Power: physical pin 1
2. Ground: physical pin 2
3. Reset:physical pin 3
4. 3.3V: physical pin 4
5. 5V: physical pin 5
6. Ground: physical pin 6
7. Ground: physical pin 7
8. Vin: physical pin 8
9. ...Moving down, we get to the analog input pins, going from 0-5.
10. A0: physical pin 9
11. A1: physical pin 10
12. A2: physical pin 11
13. A3: physical pin 12
14. A4: physical pin 13
15. A5: physical pin 14

#### Right-side pins

• We count the pins on the right side of the board from bottom to top. On the right side of your arduino, start from the bottom. Here, we get our digital inputs 0-13, followed by another ground and a couple of special function pins that we won’t use here today. So, starting from the bottom right, lets review what each pin is.
• 0: physical pin 1
• 1: physical pin 2
• 2: physical pin 3
• 3: physical pin 4
• 4: physical pin 5
• 5: physical pin 6
• 6: physical pin7
• 7: physical pin 8
• 8: physical pin 9
• 9: physical pin 10
• 10: physical pin 11
• 11: physical pin 12
• 12: physical pin 13
• 13: physical pin 14
• Ground: physical pin 15
• Special function pin: physical pin 16
• Special function pin: physical pin 17
• Special function pin: physical pin 18

• In the large compartment of the bento box, you should also have a breadboard. Let's take that out.
• Orient the breadboard by the three bumps along the shorter end, and have them closest to you.
• Compare the breadboard and your tactile graphic of the breadboard. The tactile graphic emphasizes, more than the physical breadboard, that there are two vertical columns on the left side and two vertical columns on the right side of the breadboard. These vertical columns on each side are called buses. They contain pin holes that are connected to one other. Feel on the tactile graphic the connection between the pin holes on both buses. For each individual vertical column of pin holes, electrical current runs vertically throughout the column. The grid of pin holes between the two buses, connect horizontally.
• Use the tactile graphic labels to locate both power buses and both ground buses. Power is your source of electricity, in our case it’s the USB cable that will go into our computer. Ground absorbs electricity so that we don’t short circuit our electronics (damage our Arduino). If you want to learn more after the workshop, you can read about the basics on the ITP Physical Computing Site
• The physical breadboard has the same pattern of connection, but it’s under the shell of the board and cannot be felt.
• Let’s refocus on the physical breadboard. Know that the top of the breadboard is facing up. The texture is the grid of pin holes you felt in the tactile graphic.

### Jumper Wires

• Also closest to you, on the breadboard, are jumper wires that are connecting the buses that run along the left and right sides of the breadboard.
• Let’s find the leftmost jumper wire. You’ll feel a small cylinder and that’s where the wire connects to the breadboard.
• Follow that wire over to the other side. This wire connects the power bus to the other power bus.
• Now find the cylinder of the jumper that is all the way to the right. You can follow that wire, which goes from one ground bus to the other ground bus.

### Piezo

• Pick up your piezo buzzer and the piezo buzzer tactile graphic. Feel that there is a longer and shorter pin at the bottom of the buzzer.
• The longer pin is called the anode. The plus indicates that the anode draws the power into the buzzer.
• The shorter pin is called the cathode and the negative sign indicates that that pin needs to be connected to ground.

1. Put the breadboard and Uno on the table right next to each other. Put the breadboard to the right of the Uno. Double check that the Uno is oriented so that the USB input is on the top right corner. Keep it that way the entire exercise.
2. Touch the Arduino pins on the right side of the board. Use an unfolded paper clip and count the pins.
3. Pins are numbered from 13 (5th pin hole down from the top) to 0 (18th pin hole down from the top)
4. Touch the Arduino pins on the left side of the board. Use and unfolded paper clip and count the pins.
5. 3.3V is the 4th pin down from the top.
6. Ground is on the left side, the 6th and 7th pins down from the top, and the right side, the 4th pin down from the top.

## Build Circuits with Tactile Schematics and Circuit Descriptions

• Explore your tactile schematic for a piezo, resistor in series.
• Listen to this circuit description of a piezo, resistor in series.
• Schematic image of speaker circuit with one end of a 220-ohm resistor connected to the same row as pin 5 of the Ardunio. If you’re holding the Aduino so the USB port is on the top right, Pin 5 is on the 13th pin down on the right side. The other end is connected to one of the other short rows of the breadboard. One end of the speaker is attached to that same row.The other end of the speaker is connected to the ground bus on the left side of the board. The Arduino ground pin is on the 4th pin down on the left side of the board. Schematic image of a piezo, resistor in series. Begin at pin 5, from there it makes a connection to a 220 ohm resistor. From there make a connection to a piezo speaker. The speaker connects back to Arduino ground.
• Set up your breadboard, while choosing either the tactile schematic and/or the circuit description as a blueprint to do so.

Did it work? You should hear a repetitive beeping sound coming from the piezo. Troubleshoot if needed.

## Closing/Review

Schematics are drawings of the relationships between components in an electronic device. They are blueprints used to build circuits. Circuit examples would be a simple flashlight to this laptop. There are symbols that represent real life components.

Today we used two different tools: circuit descriptions and tactile schematics as blueprints to hook up circuits. We want to improve these tactile schematics as much as possible and would be so thankful for your feedback. We will be hosting optional, paid, volunteer-based interviews after the workshop at Data & Society next door. We can offer a \$25 Visa gift card as compensation. Please let us know if you'd be willing to help. Thank you!

You are welcome to take home your Arduino kits! If you don’t want to shoulder the responsibility or mind a bunch of small components, we can safely hold the equipment for you at the NYU Ability Project, if it makes your life easier.

## Basic Screen Reader Workflows for Arduino (time permitting)

We’ve pre-programmed your Arduinos with code for you since we only have two hours, but we have information on how to do it yourself at home.

### Steps:

Install JAVA Access Bridge. Remove all Java spoor from your system:
1. From the search box open Settings, then tab to the list of items and open Apps. Tab until you get to the list of installed apps and arrow down until you hit Java of any flavor. Press return, then tab to remove and follow prompts to uninstall. Shift tab to get back to the list and repeat with any other Java-related items until there are no Java items left.
2. Go to the advanced settings dialog and remove any system variables that reference JAVA and remove any java references from the path. Reboot your machine just to give yourself that nice fresh feeling.
3. Download and install the latest 32-bit JDK from the usual Oracle location. In this case, the package is called jdk-8u144-windows-i586.exe
4. Open a command window and enable the jabswitch.
5. Launch Arduino and it works!
6. Go to Tools > Boards Manager > Select “Arduino Genuino/Uno”
7. Go to Tools > Port > Select the port that has “Arduino Genuino/Uno” at the end of the port address
8. Delete the default code in the window
9. Copy and paste the following code in there instead:
10. ---code starts below---
void setup() {
// make the speaker pin an output:
pinMode(5, OUTPUT);
}
void loop() {
// turn the speaker on at 440Hz...tone is a function that accepts two values: pin number and frequency
tone(5, 440);
delay(500);
// turn the speaker off:
noTone(5);
//This number represents the time in milliseconds the program has to wait until moving on to the next line of code.
delay(500);
}
---code end---

11. Make sure your board is plugged in with the USB and click “Verify”