Week 11 - Input Devices

Individual assignment: Measure something: add a sensor to a microcontroller board that you have designed and read it

Group assignment: Probe an input device's analog levels and digital signals

In the last week 10 for Moulding & Casting, i had made a batman made out of black panther and had temporarily added and programmed a neopixel LED as below

So this week i thought i would utilize the same with an input device. The first sensor that came to my mind was the accelerometer. So i thought of using MPU6050. I thought i could use the accelerometer in the module so that whenever i move the batman the rate of changeing of colour increases I went through several tutorials to study the working of the same. Since the MPU 6050 module used I2C communication, I found the below youtube links very useful for understanding the same

MPU 6050 module

I modified Arduino program for mpu 6050 and attiny 44 with tinywireM.h obtained from several sources

Shifting from MPU6050 to HCSR04

I thought i would use the same with attiny 44 and had found and modified the codes for the same. But i felt that there was a high chance of failure by using the same. Since i found only handful of supports for the interfacing with attiny 44 and mpu6050, i decided to test the working with another sensor before this. I desided to use the ultrasonics sensor module HC SR04 for the purpose of blinking the neopixel batman. If i get time then i will test the MPU6050 Sensor. My plan was to use this with neopixel LED WS2812B so that the colour changes instantly when the distance measured by the sensor is low

HC-SR04 Ultrasonic sensor module

WS2812B- Neopixel LED

Attiny 44 with ultrasonic sensor & neopixel

First we have to design the same in eagle by placing the required components and check whether the program and scheme would work

// NeoPixel Ring simple sketch (c) 2013 Shae Erisson
// released under the GPLv3 license to match the rest of the AdaFruit NeoPixel lib

// How many NeoPixels are attached to the Arduino?
#define NUMPIXELS 1

// When we setup the NeoPixel library, we tell it how many pixels, and which pin to use to send signals.
// Note that for older NeoPixel strips you might need to change the third parameter--see the strandtest
// example for more information on possible values.
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

int delayval = 500; // delay for half a second

const int trigPin = A0;
const int echoPin = A1;


long duration;
int distance1,distance2,distance3;

void setup() {
  // This is for Trinket 5V 16MHz, you can remove these three lines if you are not using a Trinket
#if defined (__AVR_ATtiny85__)
  if (F_CPU == 16000000) clock_prescale_set(clock_div_1);
#endif
  // End of trinket special code

  pixels.begin(); // This initializes the NeoPixel library.

  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input
}

void loop() {

  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
 
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  duration = pulseIn(echoPin, HIGH);
 
  distance1 = duration * 0.034 / 2;

  distance2 = (distance1/400)*255;
  distance3= distance2*3;

  // pixels.Color takes RGB values, from 0,0,0 up to 255,255,255
  pixels.setPixelColor(0, pixels.Color(distance1, distance2, 89)); // Moderately bright green color.

  pixels.show(); // This sends the updated pixel color to the hardware.

  delay(delayval); // Delay for a period of time (in milliseconds).

}

I found out that the neopixel i attached to my board was not working by connecting an external neopixel as below

This is what i intended.So when the distance increases the light will change.

I made another board by using the working components from the other board and adding a new atmega328 IC .Since neopixel was in small quantity with me i seperately soldered an external NEOPIXEL using wires

Removed useful components from the old PCB