Bus Buddy

Overview: Imagine you’re at a coffee shop. You’ve finished your cappuccino and are ready to head home for the night. But, alas! You miss the bus by a minute and have to wait another 45 minutes (and end up spending another $5 on coffee). Our ambient object solves this inconvenience through a real-time, responsive display that reminds people when a bus is fifteen, ten, or five minutes away. The display shows a miniature bus moving towards a bus stop and reminds people when they should be headed on their way to their bus stop.

Conceptual Design:

Context it operates in:

It is a casual display meant to be housed in public spaces like coffee shops, libraries, restaurants, etc

What it does:

A miniature bus “drives” to represent a real bus approaching a nearby stop

How/Why someone interacts with it:

People can casually glance up at the display whenever they want to. These interactions should be completely unobtrusive to their experience at a coffee shop or public space - it simply provides people with relevant and easily digestible information

Brainstorming ideas for project

Bill of Materials:
Bipolar Stepper motor
Bus Cutout
A4988 Stepper motor driver
Particle Argon
Timing Belt and TB pulley
Metal rod w/ same diam as TB pulley
2 L-brackets
4 Bearings
Wooden planks
Super Glue
Screws

Design Process:

• Laser cut a bus out of acrylic

• Get timing belt, motor, gears, and plywood to build apparatus bus will move on

• One side of the timing belt is attached to a gear that is attached to a stepper motor

• Other side of timing belt is attached to another gear on a free axis; this is to guide the belt while the other side is being controlled by the motor

//Prev Version (continuously shuttles bus back and forth):
#include "AccelStepper.h"

//Continuously moves bus back and forth. To move forward takes 5 minutes, to move back takes 1 minute

// Remember to set all MS pins high for 16th-microstepping
// defines pins
const int step = D2;
const int dir = D1;
AccelStepper Stepper(1, step, dir);
void setup() {
  Stepper.setMaxSpeed(1000);
  Stepper.moveTo(5000);
  Stepper.setSpeed(200);
  Stepper.setAcceleration(0);
}
void loop() {
   int time = Time.minute();
   transmit("time", Time.minute());
   //moves forward 1 step / 2.5 sec for 1200 steps => 5 min to span display
   Stepper.setSpeed(25);
   while (Stepper.currentPosition() < 1200){
       Stepper.runSpeed();
       delay(2500);
       transmit("position",Stepper.currentPosition());
   }
   Stepper.setSpeed(-200);
   while(Stepper.currentPosition() > 0){
       Stepper.runSpeed();
       delay(10);
       transmit("position",Stepper.currentPosition());
   }
   Stepper.setSpeed(200);
}
void transmit(char message[],int value){
  char valtext[1];
  sprintf(valtext,"%i", value);
  Particle.publish(message,valtext,PRIVATE);
}

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/*Final Code
send time for next bus through particle function. 
This will move the bus if it is at or below threshold
Resources:
https://www.robotshop.com/media/files/pdf/datasheet-1182.pdf
Accelstepper library: https://www.airspayce.com/mikem/arduino/AccelStepper/classAccelStepper.html#affbee789b5c19165846cf0409860ae79
*/

#include "AccelStepper.h"
const int tracklength = 1200; // # clicks to cover whole track
const int threshold = 5; // [minutes] consider this as whole track threshold for next bus




// defines pins
const int step = D2;
const int dir = D1;
// Define Stepper Motor
AccelStepper Stepper(1, step, dir);
void setup() {
    Stepper.setMaxSpeed(1000);
    pinMode(D7,OUTPUT);
    digitalWrite(D7, HIGH);
    Particle.function("next", bustime);
}
void loop() {
    //waiting to receive next bus time 
}
// Receives next bus time [min]
int bustime(String nextbustime){
    digitalWrite(D7, LOW);
    int bus_time = atoi(nextbustime);
    if (bus_time > threshold){
        transmit("bus is too far",bus_time);
    }
    if (bus_time == 0){
        transmit("waiting for next bus",1);
    }
    if (bus_time > 0 && bus_time <= threshold){
        transmit("next bus [min]: ",bus_time);
        // Calculate motor speed
        int speed = tracklength/(bus_time*60);
        transmit("speed [clk/sec]: ",speed);
        Stepper.setSpeed(speed); 
        // Run to end of track
        while (Stepper.currentPosition() < tracklength){ 
            Stepper.runSpeed();
        }
        transmit("Bus Arrived",1);
        // Run back to start zero time in 6 sec = 1200/(-200)
        Stepper.setSpeed(-200);
        while(Stepper.currentPosition() > 0){
            Stepper.runSpeed();
        }
        return 1;
    }
    else {
        return -1;
    }
}
void transmit(char message[],int value){
   char valtext[1];
   sprintf(valtext,"%i", value);
   Particle.publish(message,valtext,PRIVATE);
}

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