Prototyping

Introduction

To develop a better understanding about the programming behind our proposed sensor loop, a prototyping approach has been chosen. Two test setups have been created which gave new insights in the coding of the final setup, this chapter will discuss these different prototypes. For more detailed information about the different scripts see Appendices 3 & 4.

At the same time a wearable that attaches to the experience of the artwork has been designed, iterations and developments will be discussed in this chapter secondly.

Technical prototype 1

Our first setup consisted of an Arduino Uno connected to a breadboard with 6 different LED‘s and an ultrasonic distance sensor. The goal of this setup was to develop an understanding of the preciseness of the ultrasonic sensor. We quickly discovered that the ultrasonic sensor was not applicable. The sensor is unidirectional and singular in its measurement, meaning that it only reacts to the nearest object. The code of this prototype was written with if ‚statements‘ meaning if that if the ultrasonic sensor measured a certain distance X, a certain amount of Y lights will turn on. With this setup we have to determine the distances ourselves and the approach will not influence the lights gradually but rather stepwise as shown in figure 15.

Prototype 1

From left to right: the shorter the distance, the more LED‘s turn on

Current data interpretation: if distance < than X, perform Y

From left to right: the closer our testsubject, with the ESP tag, comes to the ESP anchor, the brighter the LED gets.

New data interpretation: a gradual, parabolic reaction to distance; the closer you get, the faster the reaction increases.

Technical prototype 2

The second prototype consisted of two ESP32 microcontroller, the Arduino UNO microcontroller and one LED. The ESP32 microcontrollers use the Bluetooth® signal strength of the other ESP32 to approximate their distance.. Initially they were programmed to use Bluetooth® Low Energy or BLE, in order to use less power when powering the devices with a portable battery. These ESPs approximated the distance and sent this data to a laptop over a wireless network. On the laptop, we received the data using a program written in Python, the program remaps to values between 0 & 1 which were then squared to create a more parabolic response arch and thus a more ‚sudden‘ reaction to the approach. Although the test setup worked we quickly noticed that the values were not as precise as we wanted them to be; the data had a lot of major anomalies that resulted in the LED suddenly increasing in brightness but also sometimes falling back to a previous measurement and therefore dimming while the person was still approaching. After reprogramming the ESP32‘s to use regular Bluetooth® the data quality slightly improved. Unfortunately, this data also wasn‘t precise enough, which is why we conducted futher research and ended up with DWM1001 development modules. These development boards with on-board Ultra-wideband modules are also part of our final implementation.