Sean Hartung
Published

How cold is it in my car?

I might need to know how cold it is in my car so that I know if I should warm up the vehicle or just wear gloves. You're welcome!

IntermediateShowcase (no instructions)10 hours338
How cold is it in my car?

Things used in this project

Hardware components

Photon
Particle Photon
×2
Breadboard (generic)
Breadboard (generic)
×2
OLED Expansion
Onion Corporation OLED Expansion
×1
Resistor 10k ohm
Resistor 10k ohm
×1
Temperature Sensor
Temperature Sensor
×1
Jumper wires (generic)
Jumper wires (generic)
×7

Software apps and online services

Google Sheets
Google Sheets
Maker service
IFTTT Maker service

Story

Read more

Schematics

LCD

This is the lcd display connection. I used it to display the temp sent from my temp recorder in the car.

TEMP

This is the diagram for the temp measurement. I used it outside in my car where it can stay all night and it will send back temp info.

Code

Displayer

C/C++
This will take the published temperatures from particles' event could and display it on the screen
// This #include statement was automatically added by the Particle IDE.
#include "Adafruit_SSD1306/Adafruit_SSD1306.h"

/*****************************************************************************
Particle Maker Kit Tutorial #2: Next Bus Alert

This tutorial uses a Particle Photon and the OLED screen from the Particle
Maker Kit. It uses a webhook to retrieve bus prediction times from the
NextBus Public XML feed, which must be set up first along with the webhook.
See http://docs.particle.io/tutorials/topics/maker-kit to learn how!

NOTE: This code example requires the Adafruit_SSD1306 library to be included,
so make sure to add it via the Libraries tab in the left sidebar.
******************************************************************************/

// use hardware SPI
#define OLED_DC     D3
#define OLED_CS     D4
#define OLED_RESET  D5
Adafruit_SSD1306 display(OLED_DC, OLED_RESET, OLED_CS);

String carName = "The Jeep"; // name of your bus -- FILL THIS IN!
String temperature = "99"; // #temp of the jeep (99 is a placeholder)
String soonestStr, nextSoonestStr; // strings for parsing

int  x, minX; // variables for scrolling code

void getTemp() {
    // publish the event that will trigger our Webhook
    Particle.publish("get_nex_temp");
}

// create a software timer to get new prediction times every minute
Timer timer(60000, getTemp);

void setup()   {
  // start the data retrieval timer
  timer.start();

  //subscribe to the temp 
  Particle.subscribe("temperature", handle, MY_DEVICES);


  // by default, we'll generate the high voltage from the 3.3v line internally! (neat!)
  display.begin(SSD1306_SWITCHCAPVCC);

  display.setTextSize(7);       // text size
  display.setTextColor(WHITE); // text color
  display.setTextWrap(false); // turn off text wrapping so we can do scrolling
  x    = display.width(); // set scrolling frame to display width
  minX = -1500; // 630 = 6 pixels/character * text size 7 * 15 characters * 2x slower
}

void loop() {

  // this code displays the next bus times on the OLED screen with fancy scrolling
  display.clearDisplay();
  display.setCursor(x/2, 7);
  display.print(carName);
  display.print(" is ");
  display.print(temperature);
  //display.print(soonest)
  display.print(" deg ");
  //display.print(nextSoonest)
   display.print("F ");
  display.display();
  if(--x < minX) x = display.width()*2;
}

// This is the handle for subscribing to get temperatures.
void handle(const char *name, const char *data) {

    // put the incoming data (the XML page) into a string called "str"
    temperature = String(data);


}

Temp logger

C/C++
This will record the temperature and send it to the cloud where displayer will grab it. It also uploads it to my good drive's exel page for graphing and analysis.
// This #include statement was automatically added by the Particle IDE.
#include "OneWire/OneWire.h"

/************************************************************************
This sketch reads the temperature from a 1-Wire device and then publishes
to the Particle cloud. From there, IFTTT can be used to log the date,
time, and temperature to a Google Spreadsheet. Read more in our tutorial
here: http://docs.particle.io/tutorials/topics/maker-kit

This sketch is the same as the example from the OneWire library, but
with the addition of three lines at the end to publish the data to the
cloud.

Use this sketch to read the temperature from 1-Wire devices
you have attached to your Particle device (core, p0, p1, photon, electron)

Temperature is read from: DS18S20, DS18B20, DS1822, DS2438

Expanding on the enumeration process in the address scanner, this example
reads the temperature and outputs it from known device types as it scans.

I/O setup:
These made it easy to just 'plug in' my 18B20 (note that a bare TO-92
sensor may read higher than it should if it's right next to the Photon)

D3 - 1-wire ground, or just use regular pin and comment out below.
D4 - 1-wire signal, 2K-10K resistor to D5 (3v3)
D5 - 1-wire power, ditto ground comment.

A pull-up resistor is required on the signal line. The spec calls for a 4.7K.
I have used 1K-10K depending on the bus configuration and what I had out on the
bench. If you are powering the device, they all work. If you are using parisidic
power it gets more picky about the value.
************************************************************************/

OneWire ds = OneWire(D4);  // 1-wire signal on pin D4

unsigned long lastUpdate = 0;

float lastTemp;

void setup() {
  Serial.begin(9600);
  // Set up 'power' pins, comment out if not used!
  pinMode(D3, OUTPUT);
  pinMode(D5, OUTPUT);
  digitalWrite(D3, LOW);
  digitalWrite(D5, HIGH);
}

// up to here, it is the same as the address acanner
// we need a few more variables for this example

void loop(void) {
  byte i;
  byte present = 0;
  byte type_s;
  byte data[12];
  byte addr[8];
  float celsius, fahrenheit;

  if ( !ds.search(addr)) {
    Serial.println("No more addresses.");
    Serial.println();
    ds.reset_search();
    delay(250);
    return;
  }

  // The order is changed a bit in this example
  // first the returned address is printed

  Serial.print("ROM =");
  for( i = 0; i < 8; i++) {
    Serial.write(' ');
    Serial.print(addr[i], HEX);
  }

  // second the CRC is checked, on fail,
  // print error and just return to try again

  if (OneWire::crc8(addr, 7) != addr[7]) {
      Serial.println("CRC is not valid!");
      return;
  }
  Serial.println();

  // we have a good address at this point
  // what kind of chip do we have?
  // we will set a type_s value for known types or just return

  // the first ROM byte indicates which chip
  switch (addr[0]) {
    case 0x10:
      Serial.println("  Chip = DS1820/DS18S20");
      type_s = 1;
      break;
    case 0x28:
      Serial.println("  Chip = DS18B20");
      type_s = 0;
      break;
    case 0x22:
      Serial.println("  Chip = DS1822");
      type_s = 0;
      break;
    case 0x26:
      Serial.println("  Chip = DS2438");
      type_s = 2;
      break;
    default:
      Serial.println("Unknown device type.");
      return;
  }

  // this device has temp so let's read it

  ds.reset();               // first clear the 1-wire bus
  ds.select(addr);          // now select the device we just found
  // ds.write(0x44, 1);     // tell it to start a conversion, with parasite power on at the end
  ds.write(0x44, 0);        // or start conversion in powered mode (bus finishes low)

  // just wait a second while the conversion takes place
  // different chips have different conversion times, check the specs, 1 sec is worse case + 250ms
  // you could also communicate with other devices if you like but you would need
  // to already know their address to select them.

  delay(1000);     // maybe 750ms is enough, maybe not, wait 1 sec for conversion

  // we might do a ds.depower() (parasite) here, but the reset will take care of it.

  // first make sure current values are in the scratch pad

  present = ds.reset();
  ds.select(addr);
  ds.write(0xB8,0);         // Recall Memory 0
  ds.write(0x00,0);         // Recall Memory 0

  // now read the scratch pad

  present = ds.reset();
  ds.select(addr);
  ds.write(0xBE,0);         // Read Scratchpad
  if (type_s == 2) {
    ds.write(0x00,0);       // The DS2438 needs a page# to read
  }

  // transfer and print the values

  Serial.print("  Data = ");
  Serial.print(present, HEX);
  Serial.print(" ");
  for ( i = 0; i < 9; i++) {           // we need 9 bytes
    data[i] = ds.read();
    Serial.print(data[i], HEX);
    Serial.print(" ");
  }
  Serial.print(" CRC=");
  Serial.print(OneWire::crc8(data, 8), HEX);
  Serial.println();

  // Convert the data to actual temperature
  // because the result is a 16 bit signed integer, it should
  // be stored to an "int16_t" type, which is always 16 bits
  // even when compiled on a 32 bit processor.
  int16_t raw = (data[1] << 8) | data[0];
  if (type_s == 2) raw = (data[2] << 8) | data[1];
  byte cfg = (data[4] & 0x60);

  switch (type_s) {
    case 1:
      raw = raw << 3; // 9 bit resolution default
      if (data[7] == 0x10) {
        // "count remain" gives full 12 bit resolution
        raw = (raw & 0xFFF0) + 12 - data[6];
      }
      celsius = (float)raw * 0.0625;
      break;
    case 0:
      // at lower res, the low bits are undefined, so let's zero them
      if (cfg == 0x00) raw = raw & ~7;  // 9 bit resolution, 93.75 ms
      if (cfg == 0x20) raw = raw & ~3; // 10 bit res, 187.5 ms
      if (cfg == 0x40) raw = raw & ~1; // 11 bit res, 375 ms
      // default is 12 bit resolution, 750 ms conversion time
      celsius = (float)raw * 0.0625;
      break;

    case 2:
      data[1] = (data[1] >> 3) & 0x1f;
      if (data[2] > 127) {
        celsius = (float)data[2] - ((float)data[1] * .03125);
      }else{
        celsius = (float)data[2] + ((float)data[1] * .03125);
      }
  }

  // remove random errors
  if((((celsius <= 0 && celsius > -1) && lastTemp > 5)) || celsius > 125) {
      celsius = lastTemp;
  }

  fahrenheit = celsius * 1.8 + 32.0;
  lastTemp = celsius;
  Serial.print("  Temperature = ");
  Serial.print(celsius);
  Serial.print(" Celsius, ");
  Serial.print(fahrenheit);
  Serial.println(" Fahrenheit");

  // now that we have the readings, we can publish them to the cloud
  String temperature = String(fahrenheit); // store temp in "temperature" string
  Particle.publish("temperature", temperature, PRIVATE); // publish to cloud
  delay(5000); // 5 second delay
}

Credits

Sean Hartung

Sean Hartung

1 project • 0 followers
MEGR
Thanks to Adafruit and paricle's tutorial team.

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