The updated ThingSpeak library for Arduino and Particle version 2.0.1 includes the ability to read multiple fields in one function call. The example embedded in the Arduino library can be reached in the File > Examples > ThingSpeak menu in the Arduino IDE once you have installed the latest version of the ThingSpeak library.
Reading multiple fields is especially helpful when you are using your ThingSpeak channel for control settings. For example, I have a drip irrigation system in my backyard that uses ThingSpeak channel 597924 to set the water time and the sleep time. You can see the battery level for the solar powered battery for the pump on ThingSpeak channel 592680.
Here are the basic steps using C code.
First include the library and declare variables in the setup function
include “ThingSpeak.h”
unsigned long weatherStationChannelNumber = 12397;
int statusCode = 0;
In the loop function, read all the fields together and then use the type specific built-in functions to get the values you need.
statusCode = ThingSpeak.readMultipleFields(weatherStationChannelNumber);
if(statusCode == 200)
{
int windDir = ThingSpeak.getFieldAsInt(1); // Field 1
float windSpeed = ThingSpeak.getFieldAsFloat(2); // Field 2
int percentHumid = ThingSpeak.getFieldAsInt(3); // Field 3
}
You can read the status, position information and all eight fields. See the help file at the GitHub repo for the ThingSpeak Arduino Library for more information. Your device will save the information locally until you repeat the call to readMultipleFields again.
