Week 4: Peanut Sweeper

My final project is a peanut crusher. A special feature this peanut crusher will have is that if peanuts start to move from the crushing space to the sides of the mortar during the crushing phase, there will be a scraper that scrapes the sides of the mortar to return the peanuts to the ideal space where the pestle will be exerting direct force.

Now that I know how to program a microcontroller, I want to see if my Arduino will be able to detect peanuts coming up the side. To do that, I will need to download and install a library called CapacitiveSensor. Capacitive sensors can be programmed to detect even the slightest interruption in the electric field in the air. For my project though, I don’t need the sensors to be that sensitive, or else, the mortar will keep on scraping the sides even when no peanuts are coming up into the space.

Therefore, it is important to classify thresholds. Even if the sides of the mortar detect peanuts, I don’t want it to be scraping with one or two peanuts stuck on the side. That is still a waste of power and energy. I want it to wait a little longer until “enough”, whatever we designate as “enough”, has accumulated before scraping the side.

From the Arduino project book, I found my starting point in designing a capacitive sensor.

https://www.arduino.cc/reference/en/libraries/capacitivesensor/



This is the starter code:

  
#include <CapacitiveSensor.h>


CapacitiveSensor capSensor = CapacitiveSensor(4,2);
int threshold = 1000; 
const int ledPin = 12;

void setup() { 
  Serial.begin(9600); 
  pinMode(ledPin, OUTPUT); 
}

void loop() { 
  long sensorValue = capSensor.capacitiveSensor(30); 
  Serial.println(sensorValue);
  if(sensorValue > threshold) { 
    digitalWrite(ledPin, HIGH); 
  } 
  else { 
    digitalWrite(ledPin, LOW); 
  }
  delay(10); 
}