Matthew LoveBrett Sackeli
Published

Reed Switch Bike Speedometer using Particle Argons

This project will have bi-directional communication between two Particle Argons. It will calculate the speed of a bike and graph it.

BeginnerShowcase (no instructions)87
Reed Switch Bike Speedometer using Particle Argons

Things used in this project

Hardware components

Argon
Particle Argon
×2
Battery, 3.7 V
Battery, 3.7 V
×1
Reed Switch, Wide Gap
Reed Switch, Wide Gap
×1
Tactile Switch, Top Actuated
Tactile Switch, Top Actuated
×1
Breadboard (generic)
Breadboard (generic)
×2

Software apps and online services

Particle Build Web IDE
Particle Build Web IDE
ThingSpeak API
ThingSpeak API

Story

Read more

Schematics

Argon on Bike

This is the Diagram for the Reed Switch

Stationary Argon

This is the diagram for the button.

Code

Argon on Bike

C/C++
#include <math.h>;

int reedSwitch = D2; //Declaring pin for reed switch to be used. Pin D2 must be used for the reed switch on the particle
double radius = 12.5;   //hard coding in the radius of the wheel in inches for future conversion into circumference 
double circumference;   //declaring the circumference variable
int totaltime;       //declaring the total time until the next trip on the reed switch variable
double Speed;           //declaring the Speed variable
int timer;           //declaring the timer to calculate the total time variable
int groundpin = D0;  // aux ground out.
const pin_t MY_LED = D7; //Use D7 LED
//const String key = "ME8J3G47QWK87YEP";

void myHandler(const char *event, const char *data){
 //print passed Rssi value to realterm (for testing purpose)
 Serial.println(event);
  Serial.print("(From Argon2): ");
 Serial.println(data);
//will Flash D7 LED to let know Speed was Updated
 digitalWrite(MY_LED, HIGH);
    delay(1s);
    digitalWrite(MY_LED, LOW);
 
}

void StartTimer()           
 {
      timer++;                        // Begin the timer and start counting
      delayMicroseconds(9600);        // Delay to start after a 0.0096 seconds
 }
 
 void setup(){
     
     //set up D7 led
        pinMode(MY_LED, OUTPUT);
     
     Particle.subscribe("RSSI", myHandler, MY_DEVICES);         //set up subcribe to rssi
     
        pinMode(groundpin, OUTPUT);                             //set up for reed witch ground
      
        Serial.begin(9600);                                         // Start serial monitor after a few seconds. Mainly for testing code to get it to work.
        attachInterrupt(D2, StartTimer, RISING);                    //Begins the count of seconds when the reed switch in pin D2 is set off
        pinMode(reedSwitch, INPUT_PULLUP);                         // Sets the reed switch to be an input
        timer = 0;                                                 // Sets timer to 0 seconds
        //Speed = 0;                                                 // sets the speed to 0 seconds
        totaltime = 0;                                             // sets the total time to start off at 0
        circumference = (M_PI*2) * radius;
 }
 
 void loop() {
     if (millis() - totaltime >= 1000) {  // Gets varibales to go into the loop everytime the millis() - the total time elapsed is less than 1ms
        detachInterrupt(D2);     // Stops the timer from the reading from pin D2 aka the reed switch

        Speed = ((8.181818182*circumference)/(millis() - totaltime)*timer); // Calculates the speed of the bike. The 8.18 number is converting the time in seconds into hours and inches into feet.
        timer = 0;               // Makes the timer go back to zero
        totaltime = millis();        // Makes the total time the new time
        attachInterrupt(D2, StartTimer, RISING);  // Make the StartTimer loop attach back 
        
        //added
        delay(30000);
        Particle.publish("Speed", String(Speed), PRIVATE);
       
       // return(Speed);//return speed value
  }
   //Realterm output (for testing purpose)
    Serial.print("Speed(from reedSwitch): ");
    Serial.println(Speed);   
 }

Stationary Argon

C/C++
int button = D1;     //input button is connected to D1 and the other terminal to ground.
int groundpin = D0;  // aux ground out.
int switchstate = 0; //a variable that will hold the current switch state
int lastswitchstate = 0; // a variable that will hold the previous switch state
const pin_t MY_LED = D7;
String Speed;        //declare speed value.
char publishString[40];
float rssival = 0;
float rssipct = 0;
//volatile bool mailsend = FALSE; //not needed
volatile bool rssisend = FALSE;

//Thingspeak key
const String key = "ME8J3G47QWK87YEP";

// fuction for subcribe, this will update speed
void myHandler(const char *event, const char *data){
 //print passed speed value to realterm (for testing purpose)
 Serial.println(event);
  Serial.print("(from Argon1): ");
 Serial.println(data);
 //sets subscribed Speed sata to local as Speed variable
 Speed=data;
//will Flash D7 LED to let know Speed was Updated
 digitalWrite(MY_LED, HIGH);
    delay(1s);
    digitalWrite(MY_LED, LOW);
 
}

void setup(){
    //set up D7 led
        pinMode(MY_LED, OUTPUT);
        //update Speed value
        Particle.subscribe("Speed", myHandler, MY_DEVICES);
        
        Serial.begin(9600);
        //set up for button
        pinMode(button, INPUT_PULLUP);
        pinMode(groundpin, OUTPUT);
      
        rssisend = TRUE; //for web hook
 }

void loop() {
     
    lastswitchstate = switchstate;  //copy the previous switch state to the last switch state
    switchstate = digitalRead(D1);  //read a new switch state.
    if (lastswitchstate == 0 && (switchstate == 1)) { //if both are true then...  This is a bit more advanced than just detecting a input state. It detects an edge of a signal to prevent overloading the cloud.
        //"==" compares the two values.  If equal it takes a value of "true" or 1.
       // Particle.publish("data-start/stop", String(Speed), PRIVATE);  //send the event to the particle cloud
       // delay(2000);
       
       // Particle.subscribe("data-start/stop", string(Speed), PRIVATE);
       
        rssi_update();//run the update function
       // Serial.print();
        
    }
}

void rssi_update(){
    
    //delay (2000);
    static int count = 0;
    Serial.println(count++);
    //rssival = WiFi.RSSI();  //measure RSSI
    WiFiSignal sig = WiFi.RSSI();
    rssival = sig.getStrengthValue();
    rssipct = sig.getStrength();

    sprintf(publishString, "%d", rssival);

    //sprintf(publishString,"%d",strength);
    //bool success = Particle.publish("RSSI",publishString);
    bool success = Particle.publish("RSSI", String(rssival));
    
    Particle.publish("thingSpeakWrite_All", +
        "{ \"1\": \"" + String(rssival) + "\"," +
        "\"2\": \"" + String(Speed) + "\"," +
        "\"3\": \"" + String(Speed) + "\"," +
        "\"5\": \"" + String(Speed) + "\"," +  //channel 5 due to a legacy SOC channel being calculated on thingspeak via a react.
        //"\"5\": \"" + String(var4) + "\"," +
        "\"k\": \"" + key + "\" }", 60, PRIVATE, WITH_ACK);


    if (success == TRUE) {
        //delay(10000);
        rssisend = FALSE;                        //if sent, then turn of the send flag, otherwise let it try again.
    }
}

Untitled file

C/C++
No preview (download only).

Untitled file

C/C++
No preview (download only).

Credits

Matthew Love

Matthew Love

1 project • 1 follower
Brett Sackeli

Brett Sackeli

0 projects • 0 followers

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