Lab Guide

 

Lab Guide: Cobot End-Effector Programming for Mushroom Bio-Factories

Objective: Program a 3-DOF Cobot’s end-effector to automate the handling of Orellana mushroom substrate and spore collection.

 General Wokwi Setup:

• Microcontroller: ESP32.

• Servos: Connect VCC to 5V (Red), GND to GND (Black), and Signal to the assigned Pin (Orange).

• Button: Connect one side to GND and the other to the assigned Pin.

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 Mission 1: The Substrate Shear (Sequential Logic)

Scenario: The cobot must perform a quick, forceful cut into the substrate blocks to prepare them for inoculation.

• Task: Program a fast closing motion and a slow safety opening.

• Wokwi Connection: Signal to Pin 18.

#include <ESP32Servo.h>

Servo shearServo;
const int shearPin = 18;

void setup() {
  shearServo.attach(shearPin);
  shearServo.write(0); // Initial position: Open
}

void loop() {
  // --- STUDENT CHALLENGE ---
  // 1. Move the servo to 130 degrees for a fast cut
  shearServo.______(130); 
  
  // 2. Add a delay of 200ms to allow the blade to pass through
  ______(200); 
  
  // 3. Return the servo to 0 degrees
  shearServo.write(0);
  
  // 4. Wait 2 seconds before the next substrate block arrives
  delay(2000);
}

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Mission 2: The Inoculum Mixer (Iterative Logic - Loops)

Scenario: Mix the spores into the substrate gently using a sweeping motion.

• Task: Use a for loop to create a smooth "sweep" to avoid damaging the mycelium.

• Wokwi Connection: Signal to Pin 19.

#include <ESP32Servo.h>

Servo mixerServo;
const int mixerPin = 19;

void setup() {
  mixerServo.attach(mixerPin);
}

void loop() {
  // Forward sweep: from 45 to 135 degrees
  for (int pos = 45; pos <= 135; pos++) {
    mixerServo.write(pos);
    delay(20); 
  }

  // --- STUDENT CHALLENGE ---
  // Complete the 'for' loop to return from 135 back to 45 degrees
  for (int pos = ____; pos >= ____; pos____) { 
    mixerServo.write(pos);
    delay(20);
  }
}

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Mission 3: The Nutrient Dispenser (Conditional Logic)

Scenario: Release water or nutrients into the substrate only when an operator triggers the system.

• Task: Use an if statement to activate the valve upon button press.

• Wokwi Connection: Servo Signal to Pin 21 | Button to Pin 12.

#include <ESP32Servo.h>

Servo valveServo;
const int buttonPin = 12;

void setup() {
  valveServo.attach(21);
  pinMode(buttonPin, INPUT_PULLUP); // Internal pull-up resistor
}

void loop() {
  // --- STUDENT CHALLENGE ---
  // Detect if the button is pressed (Remember: INPUT_PULLUP logic)
  if (digitalRead(buttonPin) == ____) { 
    valveServo.write(90); // Open valve
    delay(1500);          // Dispensing time
    valveServo.write(0);  // Close valve
  }
}

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Mission 4: Vertical Spore Sampler (Functions & Precision)

Scenario: Collect spore samples from the substrate surface using a high-precision vertical descent.

• Task: Organize your code using Functions. Move the servo degree-by-degree very slowly.

• Wokwi Connection: Signal to Pin 5.

#include <ESP32Servo.h>

Servo samplerServo;

void setup() {
  samplerServo.attach(5);
  samplerServo.write(0); // Start at top position
}

void loop() {
  // Call the custom functions
  descendSlowly();
  delay(1000); // Time for collection
  ascendFast();
  delay(5000); 
}

// --- STUDENT CHALLENGE ---

void descendSlowly() {
  // Use a loop to move from 0 to 100 degrees slowly
  for (int i = 0; i <= 100; i++) {
    samplerServo.write(____); // Use the iterator variable
    delay(60);               // Slow speed for precision
  }
}

void ascendFast() {
  // Move the servo back to 0 degrees instantly
  samplerServo.write(____); 
}