How can I split data coming from JSON?

Question

In my recent project, I'm working with Arduino and JSON. Now, I get data from JSON and I can able to receive in Arduino side.

Below one is my Arduino code:

#include<LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
String response = "";
bool begin = false;
void setup()
{
 Serial.begin(9600);
 lcd.begin(16, 2);
}
void loop()
{
 while(Serial.available() || !begin)
 {
 char in = Serial.read();
 if (in == '{')
 {
 begin = true;
 }
 if(begin) response += (in);
 if(in == '}')
 {
 break;
 }
 delay(1);
 }
 lcd.setCursor(0, 0);
 lcd.print(response);
}

Output :

{"TPS":"0.40","MAP":"1.05","LOAD":"14"}

Now, I want to split data means store 0.40 in one variable, 1.05 in another variable and 14 in another variable. I don't know how to split this.

• Majenko: Try this: hackingmajenkoblog.wordpress.com/2017/04/08/…
• goddland_16: Can try this JSON library: github.com/bblanchon/ArduinoJson
• Hasan: @goddland_16 I try out that library but I face one problem.
• goddland_16: if you know the number of variables and it is fixed, and the order of incoming data, you can parse yourself. Well, I can parse the example string provided all the above conditions are met.

Answer 1

Finally, I got it. I have fixed length of data. So, I use a counter to calculate the how many characters are there in my data. Now using the index of this characters, I find out proper data and then store in a different variable.

Below is my code:

#include<LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
String responseOne = "";
String responseTwo = "";
String responseThree = "";
bool begin = false;
int counter = 0;
void setup()
{
 Serial.begin(9600);
 lcd.begin(16, 2);
}
void loop()
{
 while(Serial.available() || !begin)
 {
 char in = Serial.read();
 if (in == '{')
 {
 begin = true;
 }
 if(begin)
 {
 counter++;
 if(counter >= 9 && counter <= 12) // This gives 0.40
 {
 responseOne += (in); // 0.40 store in responseOne variable
 }
 if(counter >= 22 && counter <= 25) // This gives 1.05
 {
 responseTwo += (in); // 1.05 store in responseTwo
 }
 if(counter >= 36 && counter <= 37) // This gives 14
 {
 responseThree += (in); // 14 store in responseThree
 }
 }
 if(in == '}')
 {
 break;
 }
 delay(1);
 }
 float newResponseOne = responseOne.toFloat(); // Convert string into Float
 float newResponseTwo = responseTwo.toFloat(); // Convert string into Float
 int newResponseThree = responseThree.toInt(); // Convert string into Integer
 lcd.setCursor(0, 0);
 lcd.print(newResponseOne);
 lcd.setCursor(8, 0);
 lcd.print(newResponseTwo);
 lcd.setCursor(0, 1);
 lcd.print(newResponseThree);
}