Mr. Lafond's Tech Ed Lofi Robot Build

An introductory look into Robots, Fabrication, Electronics, and coding. This projects is for my grade 9/10 Technology/General Explorations class. Through this projects, we will Ideate, Prototype, Make, and Test a basic Robot.

Students will get a chance to design their robot chassis utilizing basic woorworking skills and functions/use of hand tools and stationary equipments (mitre saw, scroll saw, pneumatic stapler). Students will learn basic electrical theory and produce simple circuits from schematic drawings. Students will also explore block-based coding/programming for controlling their robot.

**This is the first year this project has been run, this Intructable is bare bones and will be updated later on.** This was a rush instructable in order to get code easily to my students for a project that is being designed as we carry it out. I plan to get better images and details as it goes on and evolves.

Components and Supplies:

• Arduino Uno - 1
• L298N Module - 1
• HM-10 Bluetooth Module - 1
• 12v power supply - 1-2
• 9v Battery with clip - 1
• Jumper Male to Female - 11

Tools and Machines:

• Scroll Saw
• Mitre Saw
• Drill + Drill Press
• Screwdrivers
• Soldering iron

Apps and Platforms:

• Arduino IDE
• LOFI Blocks (app)

Step 1 - Renaming Bluetooth Module

First thing we need to do is rename our Bluetooth. Since we are going to have multiple in the classroom, it will be helpful to have unique names for each robot. We will also give each one a unique password.

• Open Arduino IDE
• Plug in your Uno - Select your Board and Port from the menu.
• Copy the code (included here, Highlight and Copy) (or click this link)

#include <SoftwareSerial.h>
SoftwareSerial mySerial(8,9);
void setup()
{
mySerial.begin(9600);   
Serial.begin(9600);   
delay(100);
}
void loop()
{
if (Serial.available()>0)
mySerial.write(Serial.read());
if (mySerial.available()>0)
Serial.write(mySerial.read());
}

• Open a new sketch, delete everything you see, File Paste code into the blank sketch
• Connect HM-10 to Uno following the included schematic
• On Arduino IDE - Open Serial Monitor
• make sure the Baud is at 9600 and select "Both NL & CR"
• Type 'AT' (you should get the response 'OK'
• Type 'AT+NAME' (you should get the response '+NAME=<Param>
• this will be the current name of the Bluetooth
• Now let's change the name to your group/robot name
• Type 'AT+NAMErobot (change robot to your chosen name)
• Response should be +NAME=robot
• Now let's put in password protection for the Bluetooth
• Type 'AT+Pinpassword (change password for your password - ie 246810 (must be 6 digits))
• Response should be +PIN=password
• This password will be used to connect your phone to your robot
• This step is done - unplug HM-10 from UNO

Here is the code for the LOFI Brain

• Open Arduino IDE
• Plug in your Uno - select your Board and Port from the Menu
• Copy the Code (included here, highlight and copy) (or click this link)

// LOFI Brain firmware to communicate with LOFI Robot apps and Chrome Plugin
// USB + Bluetooth version
// Author: Maciej Wojnicki
// WWW.LOFIROBOT.COM
// 28.06.2018


#include <Servo.h>


//data sending (arduino->computer) interval  
//raise it if you encouter communication jitter
const long interval = 100;


int analog1 = 0;
int analog2 = 0;
int analog3 = 0;
int analog4 = 0;
int trigPin = 12;
int echoPin = 11;
int dist;
int current_byte = 0;
int prev_byte = 0;


unsigned long previousMillis = 0;
unsigned long currentMillis;


int distance_counter = 0;
int distance_reading[50];
int distance_smooth;
int smoothing = 25;


Servo serwo1;
Servo serwo2;
Servo serwo3;
Servo serwo4;


void setup() {
  Serial.begin(9600);


  
  pinMode(2,OUTPUT);
  pinMode(4,OUTPUT);
  pinMode(3,OUTPUT);
  
  pinMode(7,OUTPUT);
  pinMode(8,OUTPUT);
  pinMode(5,OUTPUT);
  
  pinMode(10,OUTPUT);
  pinMode(9,OUTPUT);
  pinMode(6,OUTPUT);
  
  pinMode(13,OUTPUT);


    pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);


}


void loop() {


      digitalWrite(13,HIGH);
/*
    distance_counter += 1;
  if (distance_counter >= smoothing) {
    distance_counter = 0;


  }


  for (int i = smoothing - 1; i > 0; i--) {
    distance_reading[i] = distance_reading[i - 1];
  }
  distance_reading[0] = odleglosc();


  distance_smooth = 0;
  for (int i = 0; i < smoothing; i++) {
    distance_smooth = distance_smooth + distance_reading[i];
  }
  distance_smooth = distance_smooth / smoothing;


  */


currentMillis = millis();


  //receiving data from Chrome plugin
  receiving();


  // timer delay reduce data bandwidth
  if (currentMillis - previousMillis >= interval) {
    
    previousMillis = currentMillis;


    sending();


  }


}


int odleglosc() {


  long duration, distance;
  digitalWrite(trigPin, LOW);  // Added this line
  delayMicroseconds(2); // Added this line
  digitalWrite(trigPin, HIGH);


  delayMicroseconds(5); // Added this line
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH, 5000);
  distance = (duration / 2) / 29.1;


  if (distance == 0) {
    distance = 100;
  }


  return distance;
}


void receiving() {


  // 201 - buzzer
  // 202 - motor1
  // 203 - motor2


  if (Serial.available() > 0) {
  current_byte = Serial.read();
   //Serial.print(recieved);
  
//buzzer
  if (prev_byte == 201) {
      digitalWrite(13,current_byte);
  }
  outputs_set();
  prev_byte = current_byte;


  }


  
}


void outputs_set() {


//motor1
  if (prev_byte == 202) {


    if (current_byte <= 100) {
      digitalWrite(2,HIGH);
      digitalWrite(4,LOW);
      analogWrite(3,current_byte*2.35);
    }
    
    if (current_byte > 100) {
      digitalWrite(4,HIGH);
      digitalWrite(2,LOW);
      analogWrite(3,(current_byte-100)*2.35);
    }
    
  }


//motor2
  if (prev_byte == 203) {


    if (current_byte <= 100) {
      digitalWrite(7,HIGH);
      digitalWrite(8,LOW);
      analogWrite(5,current_byte*2.35);
    }
    
    if (current_byte > 100) {
      digitalWrite(8,HIGH);
      digitalWrite(7,LOW);
      analogWrite(5,(current_byte-100)*2.35);
    }
    
  }


  //output1
  if (prev_byte == 204) {
      analogWrite(10,current_byte*2.55);
  }
  //output2
    if (prev_byte == 205) {
      analogWrite(9,current_byte*2.55);
  }
  //output3
    if (prev_byte == 206) {
      analogWrite(6,current_byte*2.55);
  }
  //output4
    if (prev_byte == 207) {
      analogWrite(5,current_byte*2.55);
  }


    //servo output1
    if (prev_byte == 208) {
      servo1(current_byte);
  }
      //servo output2
    if (prev_byte == 209) {
      servo2(current_byte);
  }
      //servo output3
    if (prev_byte == 210) {
      servo3(current_byte);
  }
      //servo output4
    if (prev_byte == 211) {
      servo4(current_byte);
  }


  if (prev_byte == 212 && current_byte == 99) {
      servo_off();
  }


    if (prev_byte == 213 && current_byte == 99) {
    all_stop();
  }


  


}


void sending() {


  analog1 = analogRead(0)/10.23;
  analog2 = analogRead(1)/10.23;
  analog3 = analogRead(2)/10.23;
  analog4 = analogRead(3)/10.23;
  
//[224, 115, 2, 225, 102, 4, 226, 107, 5, 227, 63, 6]
  Serial.write(224);
  Serial.write(byte(analog1));
  Serial.write(225);
  Serial.write(byte(analog2));
  Serial.write(226);
  Serial.write(byte(analog3));
  Serial.write(227);
  Serial.write(byte(analog4));


  //odleglosc();


  Serial.write(240);
  Serial.write(byte(odleglosc()));
  // last byte "i" character as a delimiter for BT2.0 on Android
  Serial.write(105);
 


}


void servo1(int position) {
serwo1.attach(10);
serwo1.write(position*1.8);
//delay(5);
//serwo.detach();
}


void servo2(int position) {
serwo2.attach(9);
serwo2.write(position*1.8);
//delay(5);
//serwo.detach();
}
void servo3(int position) {
serwo3.attach(6);
serwo3.write(position*1.8);
//delay(5);
//serwo.detach();
}
void servo4(int position) {
serwo4.attach(5);
serwo4.write(position*1.8);
//delay(5);
//serwo.detach();
}


void servo_off() {
serwo1.detach();
serwo2.detach();
serwo3.detach();
serwo4.detach();
}


void all_stop() {
  serwo1.detach();
  serwo2.detach();
  digitalWrite(16, LOW);
  analogWrite(10, LOW);
  analogWrite(9, LOW);
  analogWrite(6, LOW);
  analogWrite(5, LOW);
  analogWrite(3, LOW);
}

• Open a new Sketch, delete everything you see, File paste into the blank Sketch
• Unplug Uno from computer
• Follow the included schematic to build your robot brain
• this is also printed and laminated

• Download the LOFI Blocks app (and the Lofi Control app if you want)
• Connect your Bluetooth (name you created and password) by clicking the circle with the robot face in it. When paired their will be a cirlce around the robot face circle.

This step will be done through in-class lessons and lots of experimentation.

Resources:

• LOFI Blocks Edu