This is the temp-logger example
The last 4 lines publish the data to the cloud.
What general steps would be required to: store data in a SD Card only if there is no connection, and once there is cloud, transfer new data and SD Card data?
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(celsius); // store temp in "temperature" string
Particle.publish("temperature", temperature, PRIVATE); // publish to dashboard
delay(60000); // 60-sec delay
}
