Ledger Art Project Guide

Table of Contents

1 Overview

In section 1 of the curriculum, students learn about ledger art, and in section 2, students play with circuits. In section 3, students combine ledger art with circuitry as they plan (Lesson 3-1 (Introduce the Ledger Art Project)), design (Lesson 3-2 (Design the Ledger Art Project)), and program (Lesson 3-3 (Program the Ledger Art Project)) ledger art-inspired projects.

This guide will present the process of creating the section 3 ledger art project using an example made by one of the authors of the curriculum. The guide will be written in the first person to emphasize design choices made by the creator and how those choices influenced the practice of computing.

2 Plan

First, I brainstormed stories that I wanted to share with others. Growing up in Los Angeles, my constant environment was a concrete jungle. In 5th grade, my class took a trip to Yosemite, where we camped and hiked for a week. This experience changed my world view and my connection with the Earth. I decided to build a visual narrative to tell the story of my first camping trip in Yosemite.

I completed the handout from Lesson 3-1 (Introduce the Ledger Art Project). I chose the following symbols to help visually tell my story:

Symbol Meaning
Backpack Hiking in the outdoors and feeling a new connection with the land
Tent and tree Sleeping in the outdoors
Open circle around me Feeling a sense of vulnerability
Sun with rays Feeling a sense of wonder and awe
Maze Finding a new sense of self within a new place and experience
Earth Environmentalism; taking care of our home

I knew that I would need to select three of these images to highlight using LEDs. I chose the following symbols and explained my reasoning:

Symbol Importance to the story
Tent Sleeping in a tent in the outdoors made me vulnerable and open to my new environment.
Maze Feeling disoriented, I tried to find a new sense of self within this scary and larger place.
Earth The outcome of this experience is a lifelong dedication to environmentalism and protecting the only home we have.

At this point, I was ready to begin designing.

3 Design

There were two parts to designing my ledger art project: drawing my visual narrative and creating a circuit diagram on top of the visual narrative.

Visual Narrative

I cut out a large piece of newspaper and glued it to card stock measuring 8.5” x 11”. I then trimmed the excess newspaper to fit the card stock.

newspaper on cardstock

I added the symbols that I planned out on top of the newspaper.

add symbols to newspaper and cardstock

Circuit Diagram

Now that the visual narrative was complete, I wanted a way to add three LEDs to the visual narrative so that I could control each of the three LEDs individually. This would mean that I would need to connect the positives of each LED to a different pin on the Circuit Playground.

I put tracing paper over my visual narrative so as not to have to start over if I made a mistake. I started by drawing where I wanted the three LEDs to be placed. I then decided that I wanted all of my lines to go to the bottom of the paper so that I can connect the circuit playground at the bottom. To further simplify the circuit design, I drew the positive lines first. I decided to make the positive sides of the LEDs face down because I figured that the positive lines would be most difficult to orient since they were being connected to three different pins, while the negative lines could all be connected to the same ground.

circuit diagram with just positive lines

I knew that negative lines cannot cross positive lines. So my negative lines would have to go above the LEDs and around on the right. I made the decision to have one continuous line connect all of the negatives of the LEDs and then go to ground on the Circuit Playground Express. I made certain that I identified which lines were positive by using red, and which were negative by using blue. I also indicated polarity using a + and - on the drawing.

circuit diagram completed

I then removed the tracing paper, and added my LEDs and copper tape to the visual narrative as depicted in my circuit diagram.

visual narrative with LEDs and copper tape

Code

Before programming, I storyboarded my light pattern using the student handout from Lesson 3-2 (Design the Ledger Art Project). In order to tell the story of how this was a sequential process, starting with the environment, and ending with my feelings about that environment, I wanted my LEDs to tell the story of how the three symbols are intertwined and caused by each other.

tent on, maze and earth off.
pause 1 second.
tent and maze on, earth off.
pause 1 second.
tent, maze, and earth on.
pause 1 second.
tent, maze, and earth flash quickly three times.
repeat.

4 Program

I wanted to be able to test my code. So I connected each of the positive lines connected to the LEDs to the following pins:

LED Pin that positive line is connected to
Tent A2
Maze A1
Earth A0

I connected the negative line to GND (ground).

Connect ledger art project to CPX

I wanted to be able to iteratively and sequentially test my code. So I decided to use functions and break up my light pattern into smaller pieces so that I could test them individually:

Function name What it does
turn on one by one A2 on, A1 and A0 off. pause 1 second. A2 and A1 on, A0 off. pause 1 second. A2, A1, and A0 on. pause 1 second.
triple flash repeat x 3 {A2, A1, A0 on. pause .3 seconds. A2, A1, A0 off. pause .3 seconds}

creating the first two functions

I tested both functions and the LEDs did what I wanted them to do! If they had not, I would have had to debug and find where I made an error in my logic.

I then made a forever loop and called the two functions I made.

Ledger art project code

I performed one final test, and was very happy with the results. Here is my final ledger art project.

gif of working ledger art project