Adding keys to object in a loop
Created by: SeanDS
I am having trouble adding keys to a JsonObject within a loop:
#include <ArduinoJson.h>
// output pins
unsigned int outputPins[8] = {2, 3, 5, 6, 7, 8, 9, 11};
// number of defined pins in list
const int NUMBER_OF_OUTPUTS = (sizeof(outputPins) / sizeof(int));
void setup()
{
// open serial communications and wait for port to open:
Serial.begin(9600);
StaticJsonBuffer<1024> jsonBuffer;
JsonObject& root = jsonBuffer.createObject();
for (int i = 0; i < NUMBER_OF_OUTPUTS; i++) {
String key = String("pin_") + String(i);
Serial.print("Key: ");
Serial.print(key);
String message = String(i);
Serial.print(", index: ");
Serial.println(message);
root.set(key, i);
}
root.printTo(Serial);
}
This outputs on the serial terminal:
Key: pin_1, index: 1
Key: pin_2, index: 2
Key: pin_3, index: 3
Key: pin_4, index: 4
Key: pin_5, index: 5
Key: pin_6, index: 6
Key: pin_7, index: 7
{"pin_7":7}
So only the last iteration of the loop is added to the object. I guess the same value is being overwritten in each iteration, but I can't figure out why.
I'm using v5.0beta1. I know you don't encourage the use of String() but I tried to figure out a way to do this with chars and it was even less successful (meaningless garbage was printed, mostly).
Any help would be greatly appreciated! This is an excellent tool - thanks a lot for sharing it.