ThingSpeakClass Class Reference

Enables an Arduino, ESP8266, Particle or other compatible hardware to write or read data to or from ThingSpeak, an open data platform for the Internet of Things with MATLAB analytics and visualization. More...

Public Member Functions
bool	begin (Client &client, const char *customHostName, unsigned int port)
	Initializes the ThingSpeak library and network settings using a custom installation of ThingSpeak. More...
bool	begin (Client &client, IPAddress customIP, unsigned int port)
	Initializes the ThingSpeak library and network settings using a custom installation of ThingSpeak. More...
bool	begin (Client &client)
	Initializes the ThingSpeak library and network settings using the ThingSpeak.com service. More...
int	writeField (unsigned long channelNumber, unsigned int field, int value, const char *writeAPIKey)
	Write an integer value to a single field in a ThingSpeak channel. More...
int	writeField (unsigned long channelNumber, unsigned int field, long value, const char *writeAPIKey)
	Write a long value to a single field in a ThingSpeak channel. More...
int	writeField (unsigned long channelNumber, unsigned int field, float value, const char *writeAPIKey)
	Write a floating point value to a single field in a ThingSpeak channel. More...
int	writeField (unsigned long channelNumber, unsigned int field, const char *value, const char *writeAPIKey)
	Write a string to a single field in a ThingSpeak channel. More...
int	writeField (unsigned long channelNumber, unsigned int field, String value, const char *writeAPIKey)
	Write a String to a single field in a ThingSpeak channel. More...
int	setField (unsigned int field, int value)
	Set the value of a single field that will be part of a multi-field update. To write multiple fields at once, call setField() for each of the fields you want to write, and then call writeFields() More...
int	setField (unsigned int field, long value)
	Set the value of a single field that will be part of a multi-field update. To write multiple fields at once, call setField() for each of the fields you want to write, and then call writeFields() More...
int	setField (unsigned int field, float value)
	Set the value of a single field that will be part of a multi-field update. To write multiple fields at once, call setField() for each of the fields you want to write, and then call writeFields() More...
int	setField (unsigned int field, const char *value)
	Set the value of a single field that will be part of a multi-field update. To write multiple fields at once, call setField() for each of the fields you want to write, and then call writeFields() More...
int	setField (unsigned int field, String value)
	Set the value of a single field that will be part of a multi-field update. To write multiple fields at once, call setField() for each of the fields you want to write, and then call writeFields() More...
int	setLatitude (float latitude)
	Set the latitude of a multi-field update. To record latitude, longitude and elevation of a write, call setField() for each of the fields you want to write, setLatitude() / setLongitude() / setElevation(), and then call writeFields() More...
int	setLongitude (float longitude)
	Set the longitude of a multi-field update. To record latitude, longitude and elevation of a write, call setField() for each of the fields you want to write, setLatitude() / setLongitude() / setElevation(), and then call writeFields() More...
int	setElevation (float elevation)
	Set the elevation of a multi-field update. To record latitude, longitude and elevation of a write, call setField() for each of the fields you want to write, setLatitude() / setLongitude() / setElevation(), and then call writeFields() More...
int	writeFields (unsigned long channelNumber, const char *writeAPIKey)
	Write a multi-field update. Call setField() for each of the fields you want to write, setLatitude() / setLongitude() / setElevation(), and then call writeFields() More...
int	writeRaw (unsigned long channelNumber, const char *postMessage, const char *writeAPIKey)
	Write a raw POST to a ThingSpeak channel. More...
int	writeRaw (unsigned long channelNumber, String postMessage, const char *writeAPIKey)
	Write a raw POST to a ThingSpeak channel. More...
String	readStringField (unsigned long channelNumber, unsigned int field, const char *readAPIKey)
	Read the latest string from a private ThingSpeak channel. More...
String	readStringField (unsigned long channelNumber, unsigned int field)
	Read the latest string from a public ThingSpeak channel. More...
float	readFloatField (unsigned long channelNumber, unsigned int field, const char *readAPIKey)
	Read the latest float from a private ThingSpeak channel. More...
float	readFloatField (unsigned long channelNumber, unsigned int field)
	Read the latest float from a public ThingSpeak channel. More...
long	readLongField (unsigned long channelNumber, unsigned int field, const char *readAPIKey)
	Read the latest long from a private ThingSpeak channel. More...
long	readLongField (unsigned long channelNumber, unsigned int field)
	Read the latest long from a public ThingSpeak channel. More...
int	readIntField (unsigned long channelNumber, unsigned int field, const char *readAPIKey)
	Read the latest int from a private ThingSpeak channel. More...
int	readIntField (unsigned long channelNumber, unsigned int field)
	Read the latest int from a public ThingSpeak channel. More...
String	readRaw (unsigned long channelNumber, String URLSuffix)
	Read a raw response from a public ThingSpeak channel. More...
String	readRaw (unsigned long channelNumber, String URLSuffix, const char *readAPIKey)
	Read a raw response from a private ThingSpeak channel. More...
int	getLastReadStatus ()
	Get the status of the previous read. More...

Detailed Description

Enables an Arduino, ESP8266, Particle or other compatible hardware to write or read data to or from ThingSpeak, an open data platform for the Internet of Things with MATLAB analytics and visualization.

Member Function Documentation

bool begin	(	Client &	client,
		const char *	customHostName,
		unsigned int	port
	)

Initializes the ThingSpeak library and network settings using a custom installation of ThingSpeak.

Parameters

client	EthernetClient, YunClient, TCPClient, or WiFiClient created earlier in the sketch
customHostName	Host name of a custom install of ThingSpeak
port	Port number to use with a custom install of ThingSpeak

Returns

Always returns true This does not validate the information passed in, or generate any calls to ThingSpeak.

#include <SPI.h>
#include <Ethernet.h>
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
EthernetClient client;

#include "ThingSpeak.h"

void setup() {
  Ethernet.begin(mac);
  ThingSpeak.begin(client,"api.thingspeak.com", 80);
}

bool begin	(	Client &	client,
		IPAddress	customIP,
		unsigned int	port
	)

Initializes the ThingSpeak library and network settings using a custom installation of ThingSpeak.

Parameters

client	EthernetClient, YunClient, TCPClient, or WiFiClient created earlier in the sketch
customIP	IP address of a custom install of ThingSpeak
port	Port number to use with a custom install of ThingSpeak

Returns

Always returns true This does not validate the information passed in, or generate any calls to ThingSpeak.

#include <SPI.h>
#include <Ethernet.h>
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
EthernetClient client;

#include "ThingSpeak.h"

void setup() {
  Ethernet.begin(mac);
  ThingSpeak.begin(client,IPAddress(184,106,153,149), 80);
}

bool begin

(

Client &

client

)

Initializes the ThingSpeak library and network settings using the ThingSpeak.com service.

Parameters

client

EthernetClient, YunClient, TCPClient, or WiFiClient created earlier in the sketch

Returns

Always returns true This does not validate the information passed in, or generate any calls to ThingSpeak.

#include <SPI.h>
#include <Ethernet.h>
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
EthernetClient client;

#include "ThingSpeak.h"

void setup() {
  Ethernet.begin(mac);
  ThingSpeak.begin(client);
}

int getLastReadStatus

(

)

Get the status of the previous read.

Returns

Generally, these are HTTP status codes. Negative values indicate an error generated by the library. Possible response codes:

• 200: OK / Success
• 404: Incorrect API key (or invalid ThingSpeak server address)
• -101: Value is out of range or string is too long (> 255 characters)
• -201: Invalid field number specified
• -210: setField() was not called before writeFields()
• -301: Failed to connect to ThingSpeak
• -302: Unexpected failure during write to ThingSpeak
• -303: Unable to parse response
• -304: Timeout waiting for server to respond
• -401: Point was not inserted (most probable cause is the rate limit of once every 15 seconds)

Remarks

The read functions will return zero or empty if there is an error. Use this function to retrieve the details.

void loop() {
  String message = ThingSpeak.readStringField(myChannelNumber, 1);
  int resultCode = ThingSpeak.getLastReadStatus();
  if(resultCode == 200)
  {
     Serial.print("Latest message is: "); 
     Serial.println(message);
  }
  else
  {
     Serial.print("Error reading message.  Status was: "); 
     Serial.println(resultCode);
  }
  delay(30000);
}

float readFloatField	(	unsigned long	channelNumber,
		unsigned int	field,
		const char *	readAPIKey
	)

Read the latest float from a private ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to read from.
readAPIKey	Read API key associated with the channel. If you share code with others, do not share this key

Returns

Value read, or 0 if the field is text or there is an error. Use getLastReadStatus() to get more specific information. Note that NAN, INFINITY, and -INFINITY are valid results.

void loop() {
  float voltage = ThingSpeak.readFloatField(myChannelNumber, 1, myReadAPIKey);
  Serial.print("Latest voltage is: "); 
  Serial.print(voltage);
  Serial.println("V"); 
  delay(30000);
}

float readFloatField	(	unsigned long	channelNumber,
		unsigned int	field
	)

Read the latest float from a public ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to read from.

Returns

Value read, or 0 if the field is text or there is an error. Use getLastReadStatus() to get more specific information. Note that NAN, INFINITY, and -INFINITY are valid results.

void loop() {
  float voltage = ThingSpeak.readFloatField(myChannelNumber, 1);
  Serial.print("Latest voltage is: "); 
  Serial.print(voltage);
  Serial.println("V"); 
  delay(30000);
}

int readIntField	(	unsigned long	channelNumber,
		unsigned int	field,
		const char *	readAPIKey
	)

Read the latest int from a private ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to read from.
readAPIKey	Read API key associated with the channel. If you share code with others, do not share this key

Returns

Value read, or 0 if the field is text or there is an error. Use getLastReadStatus() to get more specific information.

Remarks

If the value returned is out of range for an int, the result is undefined.

void loop() {
  int value = ThingSpeak.readIntField(myChannelNumber, 1, myReadAPIKey);
  Serial.print("Latest value is: "); 
  Serial.print(value);
  delay(30000);
}

int readIntField	(	unsigned long	channelNumber,
		unsigned int	field
	)

Read the latest int from a public ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to read from.

Returns

Value read, or 0 if the field is text or there is an error. Use getLastReadStatus() to get more specific information.

Remarks

If the value returned is out of range for an int, the result is undefined.

void loop() {
  int value = ThingSpeak.readIntField(myChannelNumber, 1);
  Serial.print("Latest value is: "); 
  Serial.print(value);
  delay(30000);
}

long readLongField	(	unsigned long	channelNumber,
		unsigned int	field,
		const char *	readAPIKey
	)

Read the latest long from a private ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to read from.
readAPIKey	Read API key associated with the channel. If you share code with others, do not share this key

Returns

Value read, or 0 if the field is text or there is an error. Use getLastReadStatus() to get more specific information.

void loop() {
  long value = ThingSpeak.readLongField(myChannelNumber, 1, myReadAPIKey);
  Serial.print("Latest value is: "); 
  Serial.print(value);
  delay(30000);
}

long readLongField	(	unsigned long	channelNumber,
		unsigned int	field
	)

Read the latest long from a public ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to read from.

Returns

Value read, or 0 if the field is text or there is an error. Use getLastReadStatus() to get more specific information.

void loop() {
  long value = ThingSpeak.readLongField(myChannelNumber, 1);
  Serial.print("Latest value is: "); 
  Serial.print(value);
  delay(30000);
}

String readRaw	(	unsigned long	channelNumber,
		String	URLSuffix
	)

Read a raw response from a public ThingSpeak channel.

Parameters

channelNumber	Channel number
URLSuffix	Raw URL to write to ThingSpeak as a String. See the documentation at https://thingspeak.com/docs/channels#get_feed

Returns

Response if successful, or empty string. Use getLastReadStatus() to get more specific information.

Remarks

This is low level functionality that will not be required by most users.

void loop() {
  String response = ThingSpeak.readRaw(myChannelNumber, String("feeds/days=1"));
  Serial.print("Response: "); 
  Serial.print(response);
  delay(30000);
}

String readRaw	(	unsigned long	channelNumber,
		String	URLSuffix,
		const char *	readAPIKey
	)

Read a raw response from a private ThingSpeak channel.

Parameters

channelNumber	Channel number
URLSuffix	Raw URL to write to ThingSpeak as a String. See the documentation at https://thingspeak.com/docs/channels#get_feed
readAPIKey	Read API key associated with the channel. If you share code with others, do not share this key

Returns

Response if successful, or empty string. Use getLastReadStatus() to get more specific information.

Remarks

This is low level functionality that will not be required by most users.

void loop() {
  String response = ThingSpeak.readRaw(myChannelNumber, String("feeds/days=1"), myReadAPIKey);
  Serial.print("Response: "); 
  Serial.print(response);
  delay(30000);
}

String readStringField	(	unsigned long	channelNumber,
		unsigned int	field,
		const char *	readAPIKey
	)

Read the latest string from a private ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to read from.
readAPIKey	Read API key associated with the channel. If you share code with others, do not share this key

Returns

Value read (UTF8 string), or empty string if there is an error. Use getLastReadStatus() to get more specific information.

void loop() {
  String message = ThingSpeak.readStringField(myChannelNumber, 1, myReadAPIKey);
  Serial.print("Latest message is: "); 
  Serial.println(message);
  delay(30000);
}

String readStringField	(	unsigned long	channelNumber,
		unsigned int	field
	)

Read the latest string from a public ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to read from.

Returns

Value read (UTF8), or empty string if there is an error. Use getLastReadStatus() to get more specific information.

void loop() {
  String message = ThingSpeak.readStringField(myChannelNumber, 1);
  Serial.print("Latest message is: "); 
  Serial.println(message);
  delay(30000);
}

int setElevation

(

float

elevation

)

Set the elevation of a multi-field update. To record latitude, longitude and elevation of a write, call setField() for each of the fields you want to write, setLatitude() / setLongitude() / setElevation(), and then call writeFields()

Parameters

elevation

Elevation of the measurement (meters above sea level)

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

See also

setField(), setLatitude(), setLongitude(), writeFields()

void loop() {
   int sensor1Value = analogRead(A0);
   float sensor2Voltage = analogRead(A1) * (5.0 / 1023.0);
   String sensor3Meaning;
   int sensor3Value = analogRead(A2);
   if (sensor3Value < 400) {
       sensor3Meaning = String("Too Cold!");
   } else if (sensor3Value > 600) {
       sensor3Meaning = String("Too Hot!");
   } else {
       sensor3Meaning = String("Just Right");
   }
   long timeRead = millis();

   ThingSpeak.setField(1, sensor1Value);
   ThingSpeak.setField(2, sensor2Voltage);
   ThingSpeak.setField(3, sensor3Meaning);
   ThingSpeak.setField(4, timeRead);
   setLatitude(42.2833);
   setLongitude(-71.3500);
   setElevation(100);
   ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
   delay(20000);
}

int setField	(	unsigned int	field,
		int	value
	)

Set the value of a single field that will be part of a multi-field update. To write multiple fields at once, call setField() for each of the fields you want to write, and then call writeFields()

Parameters

field	Field number (1-8) within the channel to set
value	Integer value (from -32,768 to 32,767) to set.

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

See also

setLatitude(), setLongitude(), setElevation(), writeFields()

void loop() {
   int sensor1Value = analogRead(A0);
   float sensor2Voltage = analogRead(A1) * (5.0 / 1023.0);
   String sensor3Meaning;
   int sensor3Value = analogRead(A2);
   if (sensor3Value < 400) {
       sensor3Meaning = String("Too Cold!");
   } else if (sensor3Value > 600) {
       sensor3Meaning = String("Too Hot!");
   } else {
       sensor3Meaning = String("Just Right");
   }
   long timeRead = millis();

   ThingSpeak.setField(1, sensor1Value);
   ThingSpeak.setField(2, sensor2Voltage);
   ThingSpeak.setField(3, sensor3Meaning);
   ThingSpeak.setField(4, timeRead);
   ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
   delay(20000);
}

int setField	(	unsigned int	field,
		long	value
	)

Set the value of a single field that will be part of a multi-field update. To write multiple fields at once, call setField() for each of the fields you want to write, and then call writeFields()

Parameters

field	Field number (1-8) within the channel to set
value	Long value (from -2,147,483,648 to 2,147,483,647) to write.

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

See also

setLatitude(), setLongitude(), setElevation(), writeFields()

void loop() {
   int sensor1Value = analogRead(A0);
   float sensor2Voltage = analogRead(A1) * (5.0 / 1023.0);
   String sensor3Meaning;
   int sensor3Value = analogRead(A2);
   if (sensor3Value < 400) {
       sensor3Meaning = String("Too Cold!");
   } else if (sensor3Value > 600) {
       sensor3Meaning = String("Too Hot!");
   } else {
       sensor3Meaning = String("Just Right");
   }
   long timeRead = millis();

   ThingSpeak.setField(1, sensor1Value);
   ThingSpeak.setField(2, sensor2Voltage);
   ThingSpeak.setField(3, sensor3Meaning);
   ThingSpeak.setField(4, timeRead);
   ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
   delay(20000);
}

int setField	(	unsigned int	field,
		float	value
	)

Set the value of a single field that will be part of a multi-field update. To write multiple fields at once, call setField() for each of the fields you want to write, and then call writeFields()

Parameters

field	Field number (1-8) within the channel to set
value	Floating point value (from -999999000000 to 999999000000) to write. If you need more accuracy, or a wider range, you should format the number yourself (using dtostrf) and setField() using the resulting string.

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

See also

setLatitude(), setLongitude(), setElevation(), writeFields()

void loop() {
   int sensor1Value = analogRead(A0);
   float sensor2Voltage = analogRead(A1) * (5.0 / 1023.0);
   String sensor3Meaning;
   int sensor3Value = analogRead(A2);
   if (sensor3Value < 400) {
       sensor3Meaning = String("Too Cold!");
   } else if (sensor3Value > 600) {
       sensor3Meaning = String("Too Hot!");
   } else {
       sensor3Meaning = String("Just Right");
   }
   long timeRead = millis();

   ThingSpeak.setField(1, sensor1Value);
   ThingSpeak.setField(2, sensor2Voltage);
   ThingSpeak.setField(3, sensor3Meaning);
   ThingSpeak.setField(4, timeRead);
   ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
   delay(20000);
}

int setField	(	unsigned int	field,
		const char *	value
	)

Set the value of a single field that will be part of a multi-field update. To write multiple fields at once, call setField() for each of the fields you want to write, and then call writeFields()

Parameters

field	Field number (1-8) within the channel to set
value	String to write (UTF8). ThingSpeak limits this to 255 bytes.

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

See also

setLatitude(), setLongitude(), setElevation(), writeFields()

void loop() {
   int sensor1Value = analogRead(A0);
   float sensor2Voltage = analogRead(A1) * (5.0 / 1023.0);
   String sensor3Meaning;
   int sensor3Value = analogRead(A2);
   if (sensor3Value < 400) {
       sensor3Meaning = String("Too Cold!");
   } else if (sensor3Value > 600) {
       sensor3Meaning = String("Too Hot!");
   } else {
       sensor3Meaning = String("Just Right");
   }
   long timeRead = millis();

   ThingSpeak.setField(1, sensor1Value);
   ThingSpeak.setField(2, sensor2Voltage);
   ThingSpeak.setField(3, sensor3Meaning);
   ThingSpeak.setField(4, timeRead);
   ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
   delay(20000);
}

int setField	(	unsigned int	field,
		String	value
	)

Set the value of a single field that will be part of a multi-field update. To write multiple fields at once, call setField() for each of the fields you want to write, and then call writeFields()

Parameters

field	Field number (1-8) within the channel to set
value	String to write (UTF8). ThingSpeak limits this to 255 bytes.

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

See also

setLatitude(), setLongitude(), setElevation(), writeFields()

void loop() {
   int sensor1Value = analogRead(A0);
   float sensor2Voltage = analogRead(A1) * (5.0 / 1023.0);
   String sensor3Meaning;
   int sensor3Value = analogRead(A2);
   if (sensor3Value < 400) {
       sensor3Meaning = String("Too Cold!");
   } else if (sensor3Value > 600) {
       sensor3Meaning = String("Too Hot!");
   } else {
       sensor3Meaning = String("Just Right");
   }
   long timeRead = millis();

   ThingSpeak.setField(1, sensor1Value);
   ThingSpeak.setField(2, sensor2Voltage);
   ThingSpeak.setField(3, sensor3Meaning);
   ThingSpeak.setField(4, timeRead);
   ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
   delay(20000);
}

int setLatitude

(

float

latitude

)

Set the latitude of a multi-field update. To record latitude, longitude and elevation of a write, call setField() for each of the fields you want to write, setLatitude() / setLongitude() / setElevation(), and then call writeFields()

Parameters

latitude

Latitude of the measurement (degrees N, use negative values for degrees S)

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

See also

setField(), setLongitude(), setElevation(), writeFields()

void loop() {
   int sensor1Value = analogRead(A0);
   float sensor2Voltage = analogRead(A1) * (5.0 / 1023.0);
   String sensor3Meaning;
   int sensor3Value = analogRead(A2);
   if (sensor3Value < 400) {
       sensor3Meaning = String("Too Cold!");
   } else if (sensor3Value > 600) {
       sensor3Meaning = String("Too Hot!");
   } else {
       sensor3Meaning = String("Just Right");
   }
   long timeRead = millis();

   ThingSpeak.setField(1, sensor1Value);
   ThingSpeak.setField(2, sensor2Voltage);
   ThingSpeak.setField(3, sensor3Meaning);
   ThingSpeak.setField(4, timeRead);
   ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
   setLatitude(42.2833);
   setLongitude(-71.3500);
   setElevation(100);
   delay(20000);
}

int setLongitude

(

float

longitude

)

Set the longitude of a multi-field update. To record latitude, longitude and elevation of a write, call setField() for each of the fields you want to write, setLatitude() / setLongitude() / setElevation(), and then call writeFields()

Parameters

longitude

Longitude of the measurement (degrees E, use negative values for degrees W)

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

See also

setField(), setLatitude(), setElevation(), writeFields()

void loop() {
   int sensor1Value = analogRead(A0);
   float sensor2Voltage = analogRead(A1) * (5.0 / 1023.0);
   String sensor3Meaning;
   int sensor3Value = analogRead(A2);
   if (sensor3Value < 400) {
       sensor3Meaning = String("Too Cold!");
   } else if (sensor3Value > 600) {
       sensor3Meaning = String("Too Hot!");
   } else {
       sensor3Meaning = String("Just Right");
   }
   long timeRead = millis();

   ThingSpeak.setField(1, sensor1Value);
   ThingSpeak.setField(2, sensor2Voltage);
   ThingSpeak.setField(3, sensor3Meaning);
   ThingSpeak.setField(4, timeRead);
   setLatitude(42.2833);
   setLongitude(-71.3500);
   setElevation(100);
   ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
   delay(20000);
}

int writeField	(	unsigned long	channelNumber,
		unsigned int	field,
		int	value,
		const char *	writeAPIKey
	)

Write an integer value to a single field in a ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to write to.
value	Integer value (from -32,768 to 32,767) to write.
writeAPIKey	Write API key associated with the channel. If you share code with others, do not share this key

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

Remarks

Visit https://thingspeak.com/docs/channels for more information about channels, API keys, and fields. ThingSpeak limits the number of writes to a channel to once every 15 seconds.

void loop() {
   int sensorValue = analogRead(A0);
   ThingSpeak.writeField(myChannelNumber, 1, sensorValue, myWriteAPIKey);
   delay(20000);
}

int writeField	(	unsigned long	channelNumber,
		unsigned int	field,
		long	value,
		const char *	writeAPIKey
	)

Write a long value to a single field in a ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to write to.
value	Long value (from -2,147,483,648 to 2,147,483,647) to write.
writeAPIKey	Write API key associated with the channel. If you share code with others, do not share this key

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

Remarks

Visit https://thingspeak.com/docs/channels for more information about channels, API keys, and fields. ThingSpeak limits the number of writes to a channel to once every 15 seconds.

void loop() {
   int sensorValue = analogRead(A0);
   ThingSpeak.writeField(myChannelNumber, 1, sensorValue, myWriteAPIKey);
   delay(20000);
}

int writeField	(	unsigned long	channelNumber,
		unsigned int	field,
		float	value,
		const char *	writeAPIKey
	)

Write a floating point value to a single field in a ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to write to.
value	Floating point value (from -999999000000 to 999999000000) to write. If you need more accuracy, or a wider range, you should format the number using dtostrf and writeField().
writeAPIKey	Write API key associated with the channel. If you share code with others, do not share this key

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

Remarks

Visit https://thingspeak.com/docs/channels for more information about channels, API keys, and fields. ThingSpeak limits the number of writes to a channel to once every 15 seconds.

void loop() {
   int sensorValue = analogRead(A0);
   float voltage = sensorValue * (5.0 / 1023.0);
   ThingSpeak.writeField(myChannelNumber, 1, voltage, myWriteAPIKey);
   delay(20000);
}

int writeField	(	unsigned long	channelNumber,
		unsigned int	field,
		const char *	value,
		const char *	writeAPIKey
	)

Write a string to a single field in a ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to write to.
value	String to write (UTF8 string). ThingSpeak limits this field to 255 bytes.
writeAPIKey	Write API key associated with the channel. If you share code with others, do not share this key

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

Remarks

Visit https://thingspeak.com/docs/channels for more information about channels, API keys, and fields. ThingSpeak limits the number of writes to a channel to once every 15 seconds.

void loop() {
   int sensorValue = analogRead(A0);
   if (sensorValue > 512) {
       ThingSpeak.writeField(myChannelNumber, 1, "High", myWriteAPIKey);
   }
   else {
       ThingSpeak.writeField(myChannelNumber, 1, "Low", myWriteAPIKey);
   }
   delay(20000);
}

int writeField	(	unsigned long	channelNumber,
		unsigned int	field,
		String	value,
		const char *	writeAPIKey
	)

Write a String to a single field in a ThingSpeak channel.

Parameters

channelNumber	Channel number
field	Field number (1-8) within the channel to write to.
value	Character array (zero terminated) to write (UTF8). ThingSpeak limits this field to 255 bytes.
writeAPIKey	Write API key associated with the channel. If you share code with others, do not share this key

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

Remarks

Visit https://thingspeak.com/docs/channels for more information about channels, API keys, and fields. ThingSpeak limits the number of writes to a channel to once every 15 seconds.

void loop() {
   int sensorValue = analogRead(A0);
   String meaning;
   if (sensorValue < 400) {
       meaning = String("Too Cold!");
   } else if (sensorValue > 600) {
       meaning = String("Too Hot!");
   } else {
       meaning = String("Just Right");
   }
   ThingSpeak.writeField(myChannelNumber, 1, meaning, myWriteAPIKey);
   delay(20000);
}

int writeFields	(	unsigned long	channelNumber,
		const char *	writeAPIKey
	)

Write a multi-field update. Call setField() for each of the fields you want to write, setLatitude() / setLongitude() / setElevation(), and then call writeFields()

Parameters

channelNumber	Channel number
writeAPIKey	Write API key associated with the channel. If you share code with others, do not share this key

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

See also

setField(), setLatitude(), setLongitude(), setElevation()

void loop() {
   int sensor1Value = analogRead(A0);
   float sensor2Voltage = analogRead(A1) * (5.0 / 1023.0);
   String sensor3Meaning;
   int sensor3Value = analogRead(A2);
   if (sensor3Value < 400) {
       sensor3Meaning = String("Too Cold!");
   } else if (sensor3Value > 600) {
       sensor3Meaning = String("Too Hot!");
   } else {
       sensor3Meaning = String("Just Right");
   }
   long timeRead = millis();

   ThingSpeak.setField(1, sensor1Value);
   ThingSpeak.setField(2, sensor2Voltage);
   ThingSpeak.setField(3, sensor3Meaning);
   ThingSpeak.setField(4, timeRead);
   setLatitude(42.2833);
   setLongitude(-71.3500);
   setElevation(100);
   ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
   delay(20000);
}

int writeRaw	(	unsigned long	channelNumber,
		const char *	postMessage,
		const char *	writeAPIKey
	)

Write a raw POST to a ThingSpeak channel.

Parameters

channelNumber	Channel number
postMessage	Raw URL to write to ThingSpeak as a string. See the documentation at https://thingspeak.com/docs/channels#update_feed.
writeAPIKey	Write API key associated with the channel. If you share code with others, do not share this key

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

Remarks

This is low level functionality that will not be required by most users.

void loop() {
   const char postMessage[] = "field1=23&created_at=2014-12-31%2023:59:59";

   ThingSpeak.setField(1, sensor1Value);
   ThingSpeak.setField(2, sensor2Voltage);
   ThingSpeak.setField(3, sensor3Meaning);
   ThingSpeak.setField(4, timeRead);
   ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);
   delay(20000);
}

int writeRaw	(	unsigned long	channelNumber,
		String	postMessage,
		const char *	writeAPIKey
	)

Write a raw POST to a ThingSpeak channel.

Parameters

channelNumber	Channel number
postMessage	Raw URL to write to ThingSpeak as a String. See the documentation at https://thingspeak.com/docs/channels#update_feed.
writeAPIKey	Write API key associated with the channel. If you share code with others, do not share this key

Returns

HTTP status code of 200 if successful. See getLastReadStatus() for other possible return values.

Remarks

This is low level functionality that will not be required by most users.

void loop() {
   String postMessage = String("field1=23&created_at=2014-12-31%2023:59:59");
   ThingSpeak.writeRaw(myChannelNumber, postMessage, myWriteAPIKey);
   delay(20000);
}