For milestone 2,  I gave my robot the ability to speak. This was more difficult than my first milestone was, as it required more advanced programming, and some understanding of computer file structures. However, it still involved some soldering (see fig. 1). These were skills I really have not developed, so this milestone really helped me grow in my software skills. I am modeling my robot after the Daleks from Dr. Who, so I programmed the computer to say “exterminate”. Getting the Arduino to say this was a multi-step challenge. First, I had to solder my wave shield together, and then connect it to the Arduino underneath it (see fig. 2). I also had to learn about computer file systems through converting the mp3 sound effect to a WAV file. I then had to load the WAV of the Dalek saying exterminate onto my SD card, and from there, onto the WAV shield. I had very little experience with coding Arduinos to access files, so the coding was very difficult. Essentially, I had to add the contents of the SD card to the library of the program, then reference the contents individually, by name, using a play function.

void loop(){

  play("EXTER.WAV", true);//play the file

}

The play loop that makes the Arduino speak.

 

Playing the sound file was more straightforward than the original code was, as can be seen in the final function of my code. A lot of the code is used to diagnose potential issues, and print the workings of the wave shield onto the serial monitor.

void setup() {

  

  Serial.begin (9600); // prints warnings to help users diagnose the problem

  Serial.println("Initializing SD card...");

  if (!sdCard.init()) Serial.println ("Card could not be read");

  sdCard.partialBlockRead(true); //built in SD card function that allows the file to be read faster

  if (!volume.init(sdCard)) Serial.println ("Volume could not be opened");

  if (!fatRoot.openRoot(volume)) Serial.println ("Root could not be opened");

  Serial.println ("Card initialized");

}

As you can see, a large chunk of code was made to diagnose potential problems, and update users as to the workings of the SD card.

 

I learned a lot about software this milestone, and I look forward to combining this with milestone 1.

Fig 1. The wave shield and speaker as seen from above

Fig 2. The completed circuit vertically integrated with the Arduino

First Milestone

          For Milestone one, I wired two servo motors and an ultrasonic sensor to my Arduino, and programmed the Arduino to respond to proximity by turning the servos. When the ultrasonic sensor detects an object in front of it within a certain radius, the servos whir back and forth. I had to learn how to operate servos through Arduino, but with the help of the code library, the process was rather straightforward (see code below). I also learned a bit about plugging components into the Arduino, such as learning how to use digital input/output pins. See declaration of pin outputs in the opening variables of my code below. The sensor has two functional pins, the trigger pin, and the echo pin (trigPin and echoPin). The trigPin sends out the sound wave, and the echoPin receives the sonic wave, when it bounces back to the sensor, off an object (See figure 1). This is controlled in the first commands of the loop. See code below for details.

HOW IT WORKS

The emitter on the ultrasonic sensor fires out high-frequency sound waves. The sound waves bounce off objects in front of the sensor, and are deflected back to the sensor. When the sensor detects a sound wave, the sensor measures the distance between the object and, based on the qualities of the returning sound waves. Below in figure 1 is a diagram displaying the way Ultrasonic sensors work. I programmed the Arduino to start rotating the servos whenever the distance between an object and the ultrasonic sensor is measured as smaller than 20. Attached is a diagram displaying the wiring I used. 

Starter Project

 

For my starter project, I made a TV-B-gone machine, essentially a universal remote that sends infrared (IR) waves in the direction it is pointed. IR waves are a variety of wavelengths invisible to the human eye, but visible to specialized computer sensors. The flashing pattern of the IR LEDs (Light Emitting Diode) tells most televisions to shut off. An LED is a special electronic component that creates light  when a current is run through it. The different types of IR LEDs mean that the device can communicate on a wide range of frequencies. The project is powered by two AA batteries, and several components, such as capacitors, resistors, and five transistors. These parts serve to restrict, direct, and smooth out the current flow throughout the circuit, essentially making sure that the right amount of energy gets from the battery to the LEDS (see row of black pieces on the right side of the circuit, fig.1). The circuit has five of these LEDS, four of which are infrared (see fig. 2). The human eye cannot see infrared, so there is an extra, green LED, so that the naked eye can see if the device is functioning. The circuit is activated at the press of a button, which lets power into the circuit which the computer directs the LEDS to flash, via the transistors. The whole machine is mounted on a PCB, a printable circuit board. The gadget is primarily useful as a prank, but doesn’t have much practicality outside of that. The tv-b-gone works by broadcasting IR beams on a variety of wavelengths, sending out bursts in a hit-or-miss style signal to a television’s receiver, telling the TV to turn off.  

Fig. 1: Side view of the TV-B-Gone

Fig. 2: The TV-B-Gone, as seen from above