Reading JSON file and array

tipmanfrl · January 24, 2023, 6:15pm

I am receiving a JSON text string from a web page. The JSON contains multiple objects but I can only read values from the first object. How do I read data from other objects?

In the code you can see that I am trying to read to read ID1, ID2, KLUBID1 and KLUBID2 variables. I only have null inn result.
This part is not working. Further down I get the first object in the JSON file only. But how to get data from the second json objekt?

Link to json page:
https://kapsejlads.nu/hide-horn-esp.php?klubid=13&hornset=J&json=J

Result from my code:

WiFi connected: 192.168.1.118
Setting up time
Got the time from NTP
Setting Timezone to CET-1CEST,M3.5.0,M10.5.0/3
JSON HTTP Response code: 200
[{"ID":"1","KLUBID":"13","TIDMLSTART":"5","ANTALSTART":"10","MINFORSTART":"8","KORTHORN":"1000","LANGHORN":"3000","TESTHORN":"50"},{"ID":"2","KLUBID":"10","TIDMLSTART":"6","ANTALSTART":"10","MINFORSTART":"8","KORTHORN":"1000","LANGHORN":"3000","TESTHORN":"50"}]
null
null
null
null
Time between start 5
Number of starts 10
Activate time before start 8
Horn short signal 1000
Horn long signal 3000

Part of Code:

//GET HORN_SETTINGS DATA FORMATTED AS JSON
      String serverPath5 = serverName + "?klubid=13&hornset=J&json=J"; //Set server and request data
      http.begin(client, serverPath5.c_str()); //Begin request
      int httpResponseCode = http.GET(); //Get data
      if (httpResponseCode>0) { //If http runs OK
        Serial.print("JSON HTTP Response code: "); //Print http code
        Serial.println(httpResponseCode);
        String payload5 = http.getString(); //Read http response
        Serial.println(payload5); //Print http response

        //Format JSON data
        char json[500];
        payload5.replace(" ","");
        payload5.replace("\n","");
        payload5.trim();
        payload5.remove(0,1);
        payload5.toCharArray(json, 500);

        StaticJsonDocument<1000> doc;
        deserializeJson(doc, json);

        String ID1 = doc["ID"][0];
        String KLUBID1 = doc[0]["KLUBID"];
        String ID2 = doc[1]["ID"];
        String KLUBID2 = doc[1]["KLUBID"];

        Serial.println(ID1);        
        Serial.println(KLUBID1);
        Serial.println(ID2);
        Serial.println(KLUBID1);

        //Set horn variables and print them
        ALONE_BETWEEN_START=doc["TIDMLSTART"];
        DATA_BETWEEN_START=doc["TIDMLSTART"];
        ALONE_NUMBER_OF_STARTS=doc["ANTALSTART"];
        DATA_NUMBER_OF_STARTS=doc["ANTALSTART"];
        ALONE_STARTTIME=doc["MINFORSTART"];
        DATA_STARTTIME=doc["MINFORSTART"];
        HORN_SHORTTIME=doc["KORTHORN"];
        HORN_LONGTIME=doc["LANGHORN"];
        Serial.println("Time between start "+ String(ALONE_BETWEEN_START));      
        Serial.println("Number of starts "+ String(ALONE_NUMBER_OF_STARTS));      
        Serial.println("Activate time before start "+ String(ALONE_STARTTIME));      
        Serial.println("Horn short signal "+ String(HORN_SHORTTIME));      
        Serial.println("Horn long signal "+ String(HORN_LONGTIME));

johnwasser · January 24, 2023, 6:21pm

The ArduinoJson.org "Assistant" can write the code for you.

StaticJsonDocument<512> doc;

DeserializationError error = deserializeJson(doc, http);

if (error) {
  Serial.print("deserializeJson() failed: ");
  Serial.println(error.c_str());
  return;
}

for (JsonObject item : doc.as<JsonArray>()) {

  const char* ID = item["ID"]; // "1", "2"
  const char* KLUBID = item["KLUBID"]; // "13", "10"
  const char* TIDMLSTART = item["TIDMLSTART"]; // "5", "6"
  const char* ANTALSTART = item["ANTALSTART"]; // "10", "10"
  const char* MINFORSTART = item["MINFORSTART"]; // "8", "8"
  const char* KORTHORN = item["KORTHORN"]; // "1000", "1000"
  const char* LANGHORN = item["LANGHORN"]; // "3000", "3000"
  const char* TESTHORN = item["TESTHORN"]; // "50", "50"

}

tipmanfrl · January 24, 2023, 7:28pm

Sorry, but I still don't know how to put ID=2 into a variable? Can you help further?
Or how can I Serial.Print the ID=2 from your code example?

FernandoGarcia · January 24, 2023, 7:36pm

Try this method to every key:

String KLUBID1 = doc[F("KLUBID")].as<String>();

More details here.

tipmanfrl · January 24, 2023, 7:57pm

This will only give me one value for KLUBID=13. What is the code to get KLUBID=10?

FernandoGarcia · January 24, 2023, 8:10pm

Try:

String KLUBID1 = doc[F("KLUBID")][0].as<String>();

String KLUBID2 = doc[F("KLUBID")[1].as<String>();

tipmanfrl · January 24, 2023, 8:14pm

Sorry, this doesn't work. That gives me null and null as result.

String KLUBID1 = doc[F("KLUBID")][0].as<String>();
String KLUBID2 = doc[F("KLUBID")][1].as<String>();
Serial.println(KLUBID1);        
Serial.println(KLUBID2);

FernandoGarcia · January 24, 2023, 8:16pm

Show me your full code or a minimum code that can be tested.

tipmanfrl · January 24, 2023, 8:29pm

Here is full code:

//INPUT
// I15 - D15 start stand alone
// I4  - D4 start homepage data
// I17 - TX2 

//OUTPUT
// O12 - D12 horn (relay)
// O27 - D27 device is on and ready after setup (red)
// O25 - D25 stand alone running (green)
// O32 - D32 kapsejlads data running (blue)

//når den ikke kører, så skal den hver 5 s hente Kap data, dette sikrer at data altid er opdateret.

#include <WiFi.h>          // Replace with WiFi.h for ESP32
#include <WebServer.h>     // Replace with WebServer.h for ESP32
#include <AutoConnect.h>   // For AutoConnect Wifi
#include <time.h>          // For NTP time
#include <ArduinoJSON.h>   // For reading JSON data

//For display
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

//DISPLAY
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 32 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
// The pins for I2C are defined by the Wire-library. 
// On an arduino UNO:       A4(SDA), A5(SCL)
// On an arduino MEGA 2560: 20(SDA), 21(SCL)
// On an arduino LEONARDO:   2(SDA),  3(SCL), ...
#define OLED_RESET     4 // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C ///< See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

//DISPLAY
int x,minX;
IPAddress ip;

//OUTPUTS
int HORN=12; //Output for horn
int LED_ON=27; //Output for LED, device is on
int LED_AUTO_ALONE=25; //Output for LED, program in stand alone
int LED_AUTO_DATA=32; //Output for LED, program running homepage data

//INPUTS
int START_ALONE=15; //Input to start stand alone
int START_DATA=16; //Input to start with homepage data
int START_TEST=18; //Input to start with homepage data
int BUTTON_START_ALONE=LOW;
int BUTTON_START_DATA=LOW;
int BUTTON_START_TEST=LOW;

//SETABLE VARIABLES FROM WEB
int KLUBID=13;
int ALONE_BETWEEN_START=5;
int ALONE_NUMBER_OF_STARTS=10;
int ALONE_STARTTIME=8;
int HORN_SHORTTIME=1000;
int HORN_LONGTIME=3000;
int DATA_BETWEEN_START=5;
int DATA_NUMBER_OF_STARTS=10;
int DATA_STARTTIME=8;

//CONST TO RUN PROGRAM
int HORN_STARTUPTIME=50; //Horn time during startup
int BLINKTIME=500; //Time for blinking
int STARTDELAY=0; //
int BETWEEN_START_DELAY=0;
int STARTNUM=0;
int FIVEMIN=0; //Time elapsed by 5 min
int FOURMIN=1*60*1000; //Time elapsed by 4 min
int ONEMIN=4*60*1000; //Time elapsed by 1 min
int ZEROMIN=5*60*1000; //Time elapsed by start

//AUTOCONNECT
WebServer Server;          // Replace with WebServer for ESP32
AutoConnect      Portal(Server);
AutoConnectConfig Config;

//Webside fra ESP
void rootPage() {
  char content[] = "Kapsejlads.nu - HORN";
  Server.send(200, "text/plain", content);
}

//SKRIV NTP TID
void printLocalTime(){
  struct tm timeinfo; //skriv tiden til timeinfo som tidskode
  if(!getLocalTime(&timeinfo)){ //kontroller om tid er modtaget
    Serial.println("Failed to obtain time");
    return;
  }
  Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S"); //skriv tid til monitor
}

//SÆT TIDSZONE
void setTimezone(String timezone){
  Serial.printf("  Setting Timezone to %s\n",timezone.c_str()); //skriv til monitor
  setenv("TZ",timezone.c_str(),1);  //  Now adjust the TZ.  Clock settings are adjusted to show the new local time. Indstil til CPH
  tzset(); //indstil tidszonen
}

//HENT NTP TID
void initTime(String timezone){
  struct tm timeinfo; //skriv tiden til timeinfo

  Serial.println("Setting up time"); 
  configTime(0, 0, "europe.pool.ntp.org");    // First connect to NTP server, with 0 TZ offset. Ingen tidszone eller sommertidskorrektion
  if(!getLocalTime(&timeinfo)){ //hvis NTP ikke kan hentes
    Serial.println("  Failed to obtain time");
    return;
  }
  Serial.println("  Got the time from NTP"); //NTP tid er hentet
  // Now we can set the real timezone
  setTimezone(timezone); //sæt tidszonen og dermed evt. sommertid
}


void setup() {
//DISPLAY 
  //Input Output
  pinMode(START_ALONE, INPUT);
  pinMode(START_DATA, INPUT);
  pinMode(START_TEST, INPUT);
  pinMode(HORN,OUTPUT);
  pinMode(LED_ON,OUTPUT);
  pinMode(LED_AUTO_ALONE,OUTPUT);
  pinMode(LED_AUTO_DATA,OUTPUT);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);
  //delay(2000); // Pause for 2 seconds
  display.setTextSize(1); //font størrelse
  display.setTextColor(WHITE); //skrift farve
  display.setTextWrap(false); //skift ikke linje
  display.clearDisplay(); //ryd display
  display.setCursor(0, 10); //start position
  display.print("Kapsejlads.nu"); //sæt tekst
  display.setCursor(0, 20); //ny position
  display.print("by Frank Larsen"); //sæt tekst
  display.display(); //skriv til display
  x=display.width(); //sæt x = display bredde.
  
  //AUTOCONNECT
  Serial.begin(115200);
  Serial.println();
  Config.apid = "Kapsejlads-horn";
  Config.psk = "Kapsejlads.nu";
  Portal.config(Config);

  //FORBIND WIFI    
  Server.on("/", rootPage);
  if (Portal.begin()) {
    Serial.println("WiFi connected: " + WiFi.localIP().toString());
  }

  //hent NTP tid  
  delay(500);  //vent 0,5 s, så wifi er klar
  initTime("CET-1CEST,M3.5.0,M10.5.0/3"); //hent tid for københavn, https://github.com/nayarsystems/posix_tz_db/blob/master/zones.csv

  //hent klub navn
  String serverName = "https://kapsejlads.nu/hide-horn-esp.php";
  if(WiFi.status()== WL_CONNECTED){
      //connect to homepage
      WiFiClientSecure client; //Use https
      HTTPClient http; 
      client.setInsecure(); //Get data without certificate 
      
/*      String serverPath = serverName + "?klubid=13"; //Set server and request data
      Serial.println(serverPath); //Print server path
      
      //GET CLUB NAME
      http.begin(client, serverPath.c_str()); //Begin request
      int httpResponseCode = http.GET(); //Get data
      
      if (httpResponseCode>0) { //If http runs OK
        Serial.print("HTTP Response code: "); //Print http code
        Serial.println(httpResponseCode);
        String payload1 = http.getString(); //Read http response
        Serial.println(payload1); //Print http response
      }
      else {
        Serial.print("Error code: "); //Else print http error code
        Serial.println(httpResponseCode);
      }

      //GET HORN SETTINGS STRING
      serverPath = serverName + "?klubid=13&hornset=J"; //Set server and request data
      Serial.println(serverPath); //Print server path
      
      http.begin(client, serverPath.c_str()); //Begin request
      httpResponseCode = http.GET(); //Get data
      
      if (httpResponseCode>0) { //If http runs OK
        Serial.print("HTTP Response code: "); //Print http code
        Serial.println(httpResponseCode);
        String payload2 = http.getString(); //Read http response
        Serial.println(payload2); //Print http response
      }
      else {
        Serial.print("Error code: "); //Else print http error code
        Serial.println(httpResponseCode);
      }
      
      // Free resources
      http.end(); //End http request


      //GET CLUB NAME AND HORN SETTINGS
      String serverPath3 = serverName + "?klubid=13"; //Set server and request data
      String serverPath4 = serverName + "?klubid=13&hornset=J"; //Set server and request data
      http.begin(client, serverPath3.c_str()); //Begin request
      httpResponseCode = http.GET(); //Get data
      if (httpResponseCode>0) { //If http runs OK
        String CLUBNAME = http.getString(); //Read http response
        Serial.println(CLUBNAME); //Print http response
        http.begin(client, serverPath4.c_str()); //Begin request
        String payload4= http.getString(); //Read http response
        Serial.println(payload4); //Print http response
      }
      http.end(); //End http request


      
*/

      //GET HORN_SETTINGS DATA FORMATTED AS JSON
      String serverPath5 = serverName + "?klubid=13&hornset=J&json=J"; //Set server and request data
      Serial.println(serverPath5);
      http.begin(client, serverPath5.c_str()); //Begin request
      int httpResponseCode = http.GET(); //Get data
      if (httpResponseCode>0) { //If http runs OK
        Serial.print("JSON HTTP Response code: "); //Print http code
        Serial.println(httpResponseCode);
        String payload5 = http.getString(); //Read http response
        Serial.println(payload5); //Print http response

        //Format JSON data
        char json[500];
        payload5.replace(" ","");
        payload5.replace("\n","");
        payload5.trim();
        payload5.remove(0,1);
        payload5.toCharArray(json, 500);

        Serial.println(payload5);

        StaticJsonDocument<512> doc;

        DeserializationError error = deserializeJson(doc, payload5);

        if (error) {
          Serial.print("deserializeJson() failed: ");
          Serial.println(error.c_str());
          return;
        }

        for (JsonObject item : doc.as<JsonArray>()) {

          const char* ID = item["ID"]; // "1", "2"
          const char* KLUBID = item["KLUBID"]; // "13", "10"
          const char* TIDMLSTART = item["TIDMLSTART"]; // "5", "6"
          const char* ANTALSTART = item["ANTALSTART"]; // "10", "10"
          const char* MINFORSTART = item["MINFORSTART"]; // "8", "8"
          const char* KORTHORN = item["KORTHORN"]; // "1000", "1000"
          const char* LANGHORN = item["LANGHORN"]; // "3000", "3000"
          const char* TESTHORN = item["TESTHORN"]; // "50", "50"

        }
        String KLUBID1 = doc[F("KLUBID")][0].as<String>();
        String KLUBID2 = doc[F("KLUBID")][1].as<String>();
        Serial.println(KLUBID1);        
        Serial.println(KLUBID2);        
               

/*
        StaticJsonDocument<1000> doc;
        deserializeJson(doc, json);

        String ID1 = doc["ID"][0];
        String KLUBID1 = doc[0]["KLUBID"];
        String ID2 = doc[1]["ID"];
        String KLUBID2 = doc[1]["KLUBID"];

        Serial.println(ID1);        
        Serial.println(KLUBID1);
        Serial.println(ID2);
        Serial.println(KLUBID1);

        //Set horn variables and print them
        ALONE_BETWEEN_START=doc["TIDMLSTART"];
        DATA_BETWEEN_START=doc["TIDMLSTART"];
        ALONE_NUMBER_OF_STARTS=doc["ANTALSTART"];
        DATA_NUMBER_OF_STARTS=doc["ANTALSTART"];
        ALONE_STARTTIME=doc["MINFORSTART"];
        DATA_STARTTIME=doc["MINFORSTART"];
        HORN_SHORTTIME=doc["KORTHORN"];
        HORN_LONGTIME=doc["LANGHORN"];
        Serial.println("Time between start "+ String(ALONE_BETWEEN_START));      
        Serial.println("Number of starts "+ String(ALONE_NUMBER_OF_STARTS));      
        Serial.println("Activate time before start "+ String(ALONE_STARTTIME));      
        Serial.println("Horn short signal "+ String(HORN_SHORTTIME));      
        Serial.println("Horn long signal "+ String(HORN_LONGTIME));

        //POST2        
*/              
      }
      else {
        Serial.print("Error code: "); //Else print http error code
        Serial.println(httpResponseCode);
      }
      
    }
    else {
      Serial.println("WiFi Disconnected");
    }
}

void loop() {
  //Show ESP homepage
  Portal.handleClient();

  //Get local time from ESP
  struct tm timeinfo;
  getLocalTime(&timeinfo);

  //Read input
  BUTTON_START_ALONE = digitalRead(START_ALONE);
  BUTTON_START_DATA = digitalRead(START_DATA);
  BUTTON_START_TEST = digitalRead(START_TEST);
  //Serial.print(BUTTON_START_ALONE);
  //Serial.print(BUTTON_START_DATA);
  //Serial.println(BUTTON_START_TEST);

  //display rolling text
  char message[]="Dette er min tekst"; //Text
  //minX=-12*strlen(message); //Calculate length of text string
  minX=-12*25; //Set string length to fixed size.
  display.setTextSize(2); //Font size. Max is 3
  display.clearDisplay(); //Clear the display
  display.setCursor(x,10); //Set cursor in position
  display.print(WiFi.localIP().toString()+" - "); //Put IP to display
  display.print(&timeinfo, "%H:%M:%S"); //Put time to display
  //display.print(message); //Display text
  display.display(); //Show in display
  x=x-1; //Move on display
  if(x<minX)x=display.width(); 
  //Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S"); //Print time
}

And result:
WiFi connected: 192.168.1.118

Setting up time

Failed to obtain time

https://kapsejlads.nu/hide-horn-esp.php?klubid=13&hornset=J&json=J

JSON HTTP Response code: 200

[{"ID":"1","KLUBID":"13","TIDMLSTART":"5","ANTALSTART":"10","MINFORSTART":"8","KORTHORN":"1000","LANGHORN":"3000","TESTHORN":"50"},{"ID":"2","KLUBID":"10","TIDMLSTART":"6","ANTALSTART":"10","MINFORSTART":"8","KORTHORN":"1000","LANGHORN":"3000","TESTHORN":"50"}]

{"ID":"1","KLUBID":"13","TIDMLSTART":"5","ANTALSTART":"10","MINFORSTART":"8","KORTHORN":"1000","LANGHORN":"3000","TESTHORN":"50"},{"ID":"2","KLUBID":"10","TIDMLSTART":"6","ANTALSTART":"10","MINFORSTART":"8","KORTHORN":"1000","LANGHORN":"3000","TESTHORN":"50"}]

null

FernandoGarcia · January 24, 2023, 9:25pm

Try:

#include <ArduinoJson.h>

void setup() {
  // Initialize serial port
  Serial.begin(9600);
  while (!Serial) continue;

  StaticJsonDocument<300> doc;

  char json[] =
    R"delimiter([{"ID":"1","KLUBID":"13","TIDMLSTART":"5","ANTALSTART":"10","MINFORSTART":"8","KORTHORN":"1000","LANGHORN":"3000","TESTHORN":"50"},
      {"ID":"2","KLUBID":"10","TIDMLSTART":"6","ANTALSTART":"10","MINFORSTART":"8","KORTHORN":"1000","LANGHORN":"3000","TESTHORN":"50"}])delimiter";

  // Deserialize the JSON document
  DeserializationError error = deserializeJson(doc, json);

  // Test if parsing succeeds.
  if (error) {
    Serial.print(F("deserializeJson() failed: "));
    Serial.println(error.f_str());
    return;
  }

   //serializeJsonPretty(doc, Serial);

  JsonArray nested = doc.as<JsonArray>();

  String KLUBID1 = nested[0][F("KLUBID")].as<String>();
  String KLUBID2 = nested[1][F("KLUBID")].as<String>();
  Serial.println(KLUBID1);
  Serial.println(KLUBID2);
}

void loop() {
  // not used in this example
}

tipmanfrl · January 24, 2023, 9:29pm

I still get null and null as result

tipmanfrl · January 24, 2023, 9:43pm

If I run your code only then I get 13 and 10 as result.

Can you update my full code? I can't make it run in that code.

FernandoGarcia · January 24, 2023, 9:53pm

Try:

// INPUT
// I15 - D15 start stand alone
// I4  - D4 start homepage data
// I17 - TX2

// OUTPUT
// O12 - D12 horn (relay)
// O27 - D27 device is on and ready after setup (red)
// O25 - D25 stand alone running (green)
// O32 - D32 kapsejlads data running (blue)

// når den ikke kører, så skal den hver 5 s hente Kap data, dette sikrer at data altid er opdateret.

#include <WiFi.h>          // Replace with WiFi.h for ESP32
#include <WebServer.h>     // Replace with WebServer.h for ESP32
#include <AutoConnect.h>   // For AutoConnect Wifi
#include <time.h>          // For NTP time
#include <ArduinoJSON.h>   // For reading JSON data

// For display
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// DISPLAY
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 32 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
// The pins for I2C are defined by the Wire-library.
// On an arduino UNO:       A4(SDA), A5(SCL)
// On an arduino MEGA 2560: 20(SDA), 21(SCL)
// On an arduino LEONARDO:   2(SDA),  3(SCL), ...
#define OLED_RESET     4    // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C ///< See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// DISPLAY
int x,minX;
IPAddress ip;

// OUTPUTS
int HORN = 12;           // Output for horn
int LED_ON = 27;         // Output for LED, device is on
int LED_AUTO_ALONE = 25; // Output for LED, program in stand alone
int LED_AUTO_DATA = 32;  // Output for LED, program running homepage data

// INPUTS
int START_ALONE = 15; // Input to start stand alone
int START_DATA = 16;  // Input to start with homepage data
int START_TEST = 18;  // Input to start with homepage data
int BUTTON_START_ALONE = LOW;
int BUTTON_START_DATA = LOW;
int BUTTON_START_TEST = LOW;

// SETABLE VARIABLES FROM WEB
int KLUBID = 13;
int ALONE_BETWEEN_START = 5;
int ALONE_NUMBER_OF_STARTS = 10;
int ALONE_STARTTIME = 8;
int HORN_SHORTTIME = 1000;
int HORN_LONGTIME = 3000;
int DATA_BETWEEN_START = 5;
int DATA_NUMBER_OF_STARTS = 10;
int DATA_STARTTIME = 8;

// CONST TO RUN PROGRAM
int HORN_STARTUPTIME = 50; // Horn time during startup
int BLINKTIME = 500;       // Time for blinking
int STARTDELAY = 0;        //
int BETWEEN_START_DELAY = 0;
int STARTNUM = 0;
int FIVEMIN = 0;             // Time elapsed by 5 min
int FOURMIN = 1 * 60 * 1000; // Time elapsed by 4 min
int ONEMIN = 4 * 60 * 1000;  // Time elapsed by 1 min
int ZEROMIN = 5 * 60 * 1000; // Time elapsed by start

// AUTOCONNECT
WebServer Server;          // Replace with WebServer for ESP32
AutoConnect Portal(Server);
AutoConnectConfig Config;

// Webside fra ESP
void rootPage()
{
  char content[] = "Kapsejlads.nu - HORN";
  Server.send(200, "text/plain", content);
}

// SKRIV NTP TID
void printLocalTime()
{
  struct tm timeinfo;          // skriv tiden til timeinfo som tidskode
  if(!getLocalTime(&timeinfo)) // kontroller om tid er modtaget
  {
    Serial.println("Failed to obtain time");
    return;
  }
  Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S"); // skriv tid til monitor
}

// SÆT TIDSZONE
void setTimezone(String timezone)
{
  Serial.printf("  Setting Timezone to %s\n",timezone.c_str()); // skriv til monitor
  setenv("TZ",timezone.c_str(),1);                              //  Now adjust the TZ.  Clock settings are adjusted to show the new local time. Indstil til CPH
  tzset();                                                      // indstil tidszonen
}

// HENT NTP TID
void initTime(String timezone)
{
  struct tm timeinfo; // skriv tiden til timeinfo

  Serial.println("Setting up time");
  configTime(0, 0, "europe.pool.ntp.org"); // First connect to NTP server, with 0 TZ offset. Ingen tidszone eller sommertidskorrektion
  if(!getLocalTime(&timeinfo))             // hvis NTP ikke kan hentes
  {
    Serial.println("  Failed to obtain time");
    return;
  }
  Serial.println("  Got the time from NTP"); // NTP tid er hentet
  // Now we can set the real timezone
  setTimezone(timezone);                     // sæt tidszonen og dermed evt. sommertid
}


void setup()
{
// DISPLAY
  // Input Output
  pinMode(START_ALONE, INPUT);
  pinMode(START_DATA, INPUT);
  pinMode(START_TEST, INPUT);
  pinMode(HORN,OUTPUT);
  pinMode(LED_ON,OUTPUT);
  pinMode(LED_AUTO_ALONE,OUTPUT);
  pinMode(LED_AUTO_DATA,OUTPUT);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);
  // delay(2000); // Pause for 2 seconds
  display.setTextSize(1);           // font størrelse
  display.setTextColor(WHITE);      // skrift farve
  display.setTextWrap(false);       // skift ikke linje
  display.clearDisplay();           // ryd display
  display.setCursor(0, 10);         // start position
  display.print("Kapsejlads.nu");   // sæt tekst
  display.setCursor(0, 20);         // ny position
  display.print("by Frank Larsen"); // sæt tekst
  display.display();                // skriv til display
  x = display.width();              // sæt x = display bredde.

  // AUTOCONNECT
  Serial.begin(115200);
  Serial.println();
  Config.apid = "Kapsejlads-horn";
  Config.psk = "Kapsejlads.nu";
  Portal.config(Config);

  // FORBIND WIFI
  Server.on("/", rootPage);
  if (Portal.begin())
  {
    Serial.println("WiFi connected: " + WiFi.localIP().toString());
  }

  // hent NTP tid
  delay(500);                             // vent 0,5 s, så wifi er klar
  initTime("CET-1CEST,M3.5.0,M10.5.0/3"); // hent tid for københavn, https://github.com/nayarsystems/posix_tz_db/blob/master/zones.csv

  // hent klub navn
  String serverName = "https://kapsejlads.nu/hide-horn-esp.php";
  if(WiFi.status() == WL_CONNECTED)
  {
    // connect to homepage
    WiFiClientSecure client; // Use https
    HTTPClient http;
    client.setInsecure();    // Get data without certificate

/*      String serverPath = serverName + "?klubid=13"; //Set server and request data
      Serial.println(serverPath); //Print server path

      //GET CLUB NAME
      http.begin(client, serverPath.c_str()); //Begin request
      int httpResponseCode = http.GET(); //Get data

      if (httpResponseCode>0) { //If http runs OK
        Serial.print("HTTP Response code: "); //Print http code
        Serial.println(httpResponseCode);
        String payload1 = http.getString(); //Read http response
        Serial.println(payload1); //Print http response
      }
      else {
        Serial.print("Error code: "); //Else print http error code
        Serial.println(httpResponseCode);
      }

      //GET HORN SETTINGS STRING
      serverPath = serverName + "?klubid=13&hornset=J"; //Set server and request data
      Serial.println(serverPath); //Print server path

      http.begin(client, serverPath.c_str()); //Begin request
      httpResponseCode = http.GET(); //Get data

      if (httpResponseCode>0) { //If http runs OK
        Serial.print("HTTP Response code: "); //Print http code
        Serial.println(httpResponseCode);
        String payload2 = http.getString(); //Read http response
        Serial.println(payload2); //Print http response
      }
      else {
        Serial.print("Error code: "); //Else print http error code
        Serial.println(httpResponseCode);
      }

      // Free resources
      http.end(); //End http request


      //GET CLUB NAME AND HORN SETTINGS
      String serverPath3 = serverName + "?klubid=13"; //Set server and request data
      String serverPath4 = serverName + "?klubid=13&hornset=J"; //Set server and request data
      http.begin(client, serverPath3.c_str()); //Begin request
      httpResponseCode = http.GET(); //Get data
      if (httpResponseCode>0) { //If http runs OK
        String CLUBNAME = http.getString(); //Read http response
        Serial.println(CLUBNAME); //Print http response
        http.begin(client, serverPath4.c_str()); //Begin request
        String payload4= http.getString(); //Read http response
        Serial.println(payload4); //Print http response
      }
      http.end(); //End http request



 */

    // GET HORN_SETTINGS DATA FORMATTED AS JSON
    String serverPath5 = serverName + "?klubid=13&hornset=J&json=J"; // Set server and request data
    Serial.println(serverPath5);
    http.begin(client, serverPath5.c_str());                         // Begin request
    int httpResponseCode = http.GET();                               // Get data
    if (httpResponseCode > 0)                                        // If http runs OK
    {
      Serial.print("JSON HTTP Response code: ");                     // Print http code
      Serial.println(httpResponseCode);
      String payload5 = http.getString();                            // Read http response
      Serial.println(payload5);                                      // Print http response

      // Format JSON data
      char json[500];
      payload5.replace(" ","");
      payload5.replace("\n","");
      payload5.trim();
      payload5.remove(0,1);
      payload5.toCharArray(json, 500);

      Serial.println(payload5);

      StaticJsonDocument<512> doc;

      DeserializationError error = deserializeJson(doc, payload5);

      if (error)
      {
        Serial.print("deserializeJson() failed: ");
        Serial.println(error.c_str());
        return;
      }

      JsonArray nested = doc.as<JsonArray>();

      String KLUBID1 = nested[0][F("KLUBID")].as<String>();
      String KLUBID2 = nested[1][F("KLUBID")].as<String>();
      Serial.println(KLUBID1);
      Serial.println(KLUBID2);
    }
    else
    {
      Serial.print("Error code: ");   // Else print http error code
      Serial.println(httpResponseCode);
    }

  }
  else
  {
    Serial.println("WiFi Disconnected");
  }
}

void loop()
{
  // Show ESP homepage
  Portal.handleClient();

  // Get local time from ESP
  struct tm timeinfo;
  getLocalTime(&timeinfo);

  // Read input
  BUTTON_START_ALONE = digitalRead(START_ALONE);
  BUTTON_START_DATA = digitalRead(START_DATA);
  BUTTON_START_TEST = digitalRead(START_TEST);
  // Serial.print(BUTTON_START_ALONE);
  // Serial.print(BUTTON_START_DATA);
  // Serial.println(BUTTON_START_TEST);

  // display rolling text
  char message[] = "Dette er min tekst";            // Text
  // minX=-12*strlen(message); //Calculate length of text string
  minX = -12 * 25;                                  // Set string length to fixed size.
  display.setTextSize(2);                           // Font size. Max is 3
  display.clearDisplay();                           // Clear the display
  display.setCursor(x,10);                          // Set cursor in position
  display.print(WiFi.localIP().toString() + " - "); // Put IP to display
  display.print(&timeinfo, "%H:%M:%S");             // Put time to display
  // display.print(message); //Display text
  display.display();                                // Show in display
  x = x - 1;                                        // Move on display
  if(x < minX)
  {
    x = display.width();
  }
  // Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S"); //Print time
}

tipmanfrl · January 24, 2023, 10:09pm

The full code gives null and null as result. Sorry. Seems like something in the code is desturbing the result.

tipmanfrl · January 24, 2023, 10:18pm

Finally!!!! Below code works.
Plz reply, so I can mark answer as solution.

This code destroys the result:

char json[500];
      payload5.replace(" ","");
      payload5.replace("\n","");
      payload5.trim();
      payload5.remove(0,1);
      payload5.toCharArray(json, 500);

Only use the code below

// INPUT
// I15 - D15 start stand alone
// I4  - D4 start homepage data
// I17 - TX2

// OUTPUT
// O12 - D12 horn (relay)
// O27 - D27 device is on and ready after setup (red)
// O25 - D25 stand alone running (green)
// O32 - D32 kapsejlads data running (blue)

// når den ikke kører, så skal den hver 5 s hente Kap data, dette sikrer at data altid er opdateret.

#include <WiFi.h>          // Replace with WiFi.h for ESP32
#include <WebServer.h>     // Replace with WebServer.h for ESP32
#include <AutoConnect.h>   // For AutoConnect Wifi
#include <time.h>          // For NTP time
#include <ArduinoJSON.h>   // For reading JSON data

// For display
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// DISPLAY
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 32 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
// The pins for I2C are defined by the Wire-library.
// On an arduino UNO:       A4(SDA), A5(SCL)
// On an arduino MEGA 2560: 20(SDA), 21(SCL)
// On an arduino LEONARDO:   2(SDA),  3(SCL), ...
#define OLED_RESET     4    // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C ///< See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// DISPLAY
int x,minX;
IPAddress ip;

// OUTPUTS
int HORN = 12;           // Output for horn
int LED_ON = 27;         // Output for LED, device is on
int LED_AUTO_ALONE = 25; // Output for LED, program in stand alone
int LED_AUTO_DATA = 32;  // Output for LED, program running homepage data

// INPUTS
int START_ALONE = 15; // Input to start stand alone
int START_DATA = 16;  // Input to start with homepage data
int START_TEST = 18;  // Input to start with homepage data
int BUTTON_START_ALONE = LOW;
int BUTTON_START_DATA = LOW;
int BUTTON_START_TEST = LOW;

// SETABLE VARIABLES FROM WEB
int KLUBID = 13;
int ALONE_BETWEEN_START = 5;
int ALONE_NUMBER_OF_STARTS = 10;
int ALONE_STARTTIME = 8;
int HORN_SHORTTIME = 1000;
int HORN_LONGTIME = 3000;
int DATA_BETWEEN_START = 5;
int DATA_NUMBER_OF_STARTS = 10;
int DATA_STARTTIME = 8;

// CONST TO RUN PROGRAM
int HORN_STARTUPTIME = 50; // Horn time during startup
int BLINKTIME = 500;       // Time for blinking
int STARTDELAY = 0;        //
int BETWEEN_START_DELAY = 0;
int STARTNUM = 0;
int FIVEMIN = 0;             // Time elapsed by 5 min
int FOURMIN = 1 * 60 * 1000; // Time elapsed by 4 min
int ONEMIN = 4 * 60 * 1000;  // Time elapsed by 1 min
int ZEROMIN = 5 * 60 * 1000; // Time elapsed by start

// AUTOCONNECT
WebServer Server;          // Replace with WebServer for ESP32
AutoConnect Portal(Server);
AutoConnectConfig Config;

// Webside fra ESP
void rootPage()
{
  char content[] = "Kapsejlads.nu - HORN";
  Server.send(200, "text/plain", content);
}

// SKRIV NTP TID
void printLocalTime()
{
  struct tm timeinfo;          // skriv tiden til timeinfo som tidskode
  if(!getLocalTime(&timeinfo)) // kontroller om tid er modtaget
  {
    Serial.println("Failed to obtain time");
    return;
  }
  Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S"); // skriv tid til monitor
}

// SÆT TIDSZONE
void setTimezone(String timezone)
{
  Serial.printf("  Setting Timezone to %s\n",timezone.c_str()); // skriv til monitor
  setenv("TZ",timezone.c_str(),1);                              //  Now adjust the TZ.  Clock settings are adjusted to show the new local time. Indstil til CPH
  tzset();                                                      // indstil tidszonen
}

// HENT NTP TID
void initTime(String timezone)
{
  struct tm timeinfo; // skriv tiden til timeinfo

  Serial.println("Setting up time");
  configTime(0, 0, "europe.pool.ntp.org"); // First connect to NTP server, with 0 TZ offset. Ingen tidszone eller sommertidskorrektion
  if(!getLocalTime(&timeinfo))             // hvis NTP ikke kan hentes
  {
    Serial.println("  Failed to obtain time");
    return;
  }
  Serial.println("  Got the time from NTP"); // NTP tid er hentet
  // Now we can set the real timezone
  setTimezone(timezone);                     // sæt tidszonen og dermed evt. sommertid
}


void setup()
{
// DISPLAY
  // Input Output
  pinMode(START_ALONE, INPUT);
  pinMode(START_DATA, INPUT);
  pinMode(START_TEST, INPUT);
  pinMode(HORN,OUTPUT);
  pinMode(LED_ON,OUTPUT);
  pinMode(LED_AUTO_ALONE,OUTPUT);
  pinMode(LED_AUTO_DATA,OUTPUT);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);
  // delay(2000); // Pause for 2 seconds
  display.setTextSize(1);           // font størrelse
  display.setTextColor(WHITE);      // skrift farve
  display.setTextWrap(false);       // skift ikke linje
  display.clearDisplay();           // ryd display
  display.setCursor(0, 10);         // start position
  display.print("Kapsejlads.nu");   // sæt tekst
  display.setCursor(0, 20);         // ny position
  display.print("by Frank Larsen"); // sæt tekst
  display.display();                // skriv til display
  x = display.width();              // sæt x = display bredde.

  // AUTOCONNECT
  Serial.begin(115200);
  Serial.println();
  Config.apid = "Kapsejlads-horn";
  Config.psk = "Kapsejlads.nu";
  Portal.config(Config);

  // FORBIND WIFI
  Server.on("/", rootPage);
  if (Portal.begin())
  {
    Serial.println("WiFi connected: " + WiFi.localIP().toString());
  }

  // hent NTP tid
  delay(500);                             // vent 0,5 s, så wifi er klar
  initTime("CET-1CEST,M3.5.0,M10.5.0/3"); // hent tid for københavn, https://github.com/nayarsystems/posix_tz_db/blob/master/zones.csv

  // hent klub navn
  String serverName = "https://kapsejlads.nu/hide-horn-esp.php";
  if(WiFi.status() == WL_CONNECTED)
  {
    // connect to Kap homepage
    WiFiClientSecure client; // Use https
    HTTPClient http;
    client.setInsecure();    // Get data without certificate

/*      String serverPath = serverName + "?klubid=13"; //Set server and request data
      Serial.println(serverPath); //Print server path

      //GET CLUB NAME
      http.begin(client, serverPath.c_str()); //Begin request
      int httpResponseCode = http.GET(); //Get data

      if (httpResponseCode>0) { //If http runs OK
        Serial.print("HTTP Response code: "); //Print http code
        Serial.println(httpResponseCode);
        String payload1 = http.getString(); //Read http response
        Serial.println(payload1); //Print http response
      }
      else {
        Serial.print("Error code: "); //Else print http error code
        Serial.println(httpResponseCode);
      }

      //GET HORN SETTINGS STRING
      serverPath = serverName + "?klubid=13&hornset=J"; //Set server and request data
      Serial.println(serverPath); //Print server path

      http.begin(client, serverPath.c_str()); //Begin request
      httpResponseCode = http.GET(); //Get data

      if (httpResponseCode>0) { //If http runs OK
        Serial.print("HTTP Response code: "); //Print http code
        Serial.println(httpResponseCode);
        String payload2 = http.getString(); //Read http response
        Serial.println(payload2); //Print http response
      }
      else {
        Serial.print("Error code: "); //Else print http error code
        Serial.println(httpResponseCode);
      }

      // Free resources
      http.end(); //End http request


      //GET CLUB NAME AND HORN SETTINGS
      String serverPath3 = serverName + "?klubid=13"; //Set server and request data
      String serverPath4 = serverName + "?klubid=13&hornset=J"; //Set server and request data
      http.begin(client, serverPath3.c_str()); //Begin request
      httpResponseCode = http.GET(); //Get data
      if (httpResponseCode>0) { //If http runs OK
        String CLUBNAME = http.getString(); //Read http response
        Serial.println(CLUBNAME); //Print http response
        http.begin(client, serverPath4.c_str()); //Begin request
        String payload4= http.getString(); //Read http response
        Serial.println(payload4); //Print http response
      }
      http.end(); //End http request



 */

    // GET HORN_SETTINGS DATA FORMATTED AS JSON
    String serverPath5 = serverName + "?klubid=13&hornset=J&json=J"; // Set server and request data
    Serial.println(serverPath5);
    http.begin(client, serverPath5.c_str());                         // Begin request
    int httpResponseCode = http.GET();                               // Get data
    if (httpResponseCode > 0){                                       // If http runs OK
      Serial.print("JSON HTTP Response code: ");                     // Print http code
      Serial.println(httpResponseCode);
      String payload5 = http.getString();                            // Read http response
      Serial.println(payload5);                                      // Print http response

      StaticJsonDocument<512> doc;
      DeserializationError error = deserializeJson(doc, payload5);
      if (error){
        Serial.print("deserializeJson() failed: ");
        Serial.println(error.c_str());
        return;
      }
      JsonArray nested = doc.as<JsonArray>();

      String KLUBID1 = nested[0][F("KLUBID")].as<String>();
      String KLUBID2 = nested[1][F("KLUBID")].as<String>();
      Serial.println(KLUBID1);
      Serial.println(KLUBID2);
    


    } else {
      Serial.print("Error code: ");   // Else print http error code
      Serial.println(httpResponseCode);
    }

  }
  else
  {
    Serial.println("WiFi Disconnected");
  }
}

void loop()
{
  // Show ESP homepage
  Portal.handleClient();

  // Get local time from ESP
  struct tm timeinfo;
  getLocalTime(&timeinfo);

  // Read input
  BUTTON_START_ALONE = digitalRead(START_ALONE);
  BUTTON_START_DATA = digitalRead(START_DATA);
  BUTTON_START_TEST = digitalRead(START_TEST);
  // Serial.print(BUTTON_START_ALONE);
  // Serial.print(BUTTON_START_DATA);
  // Serial.println(BUTTON_START_TEST);

  // display rolling text
  char message[] = "Dette er min tekst";            // Text
  // minX=-12*strlen(message); //Calculate length of text string
  minX = -12 * 25;                                  // Set string length to fixed size.
  display.setTextSize(2);                           // Font size. Max is 3
  display.clearDisplay();                           // Clear the display
  display.setCursor(x,10);                          // Set cursor in position
  display.print(WiFi.localIP().toString() + " - "); // Put IP to display
  display.print(&timeinfo, "%H:%M:%S");             // Put time to display
  // display.print(message); //Display text
  display.display();                                // Show in display
  x = x - 1;                                        // Move on display
  if(x < minX)
  {
    x = display.width();
  }
  // Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S"); //Print time
}

tipmanfrl · January 24, 2023, 10:26pm

Additional question. If I dont know the size of the json how can I change code to make a dynamical json size? What are the benefits of using a static json?

FernandoGarcia · January 24, 2023, 10:27pm

Glad to hear!

You can mark the post #10 as solution.

FernandoGarcia · January 24, 2023, 10:33pm

Check it:

johnwasser · January 24, 2023, 10:43pm

After:

 const char* ID = item["ID"]; // "1", "2"

Put:

  Serial.print("ID=");
  Serial.println(ID);

tipmanfrl · January 25, 2023, 6:19am

I have now changed the json to dynamic. Works fine.

In the file there can be random KLUBIDs (number of objects).
Question: How do I run through the JSON and print all KLUBIDs?

The while code is not working correct.

I have the following code now, where I find the length of the json (number of objects in the json):

if (httpResponseCode > 0){                                       // If http runs OK
      Serial.print("JSON HTTP Response code: ");                     // Print http code
      Serial.println(httpResponseCode);
      String payload5 = http.getString();                            // Read http response
      Serial.println(payload5);                                      // Print http response

      //https://arduinojson.org/ --> Assistent menu, to generate json code without nested elements
      //StaticJsonDocument<512> doc;
      DynamicJsonDocument doc(2048);
      DeserializationError error = deserializeJson(doc, payload5);
      if (error){
        Serial.print("deserializeJson() failed: ");
        Serial.println(error.c_str());
        return;
      }
      JsonArray nested = doc.as<JsonArray>();

      String KLUBID1 = nested[0][F("KLUBID")].as<String>();
      String KLUBID2 = nested[1][F("KLUBID")].as<String>();
      String TIDMLSTART1 = nested[0][F("TIDMLSTART")].as<String>();
      String TIDMLSTART2 = nested[1][F("TIDMLSTART")].as<String>();
      Serial.println(KLUBID1);
      Serial.println(KLUBID2);
      Serial.println(TIDMLSTART1);
      Serial.println(TIDMLSTART2);

      int i=0;
      int arrayLength = doc.size();
      Serial.print(arrayLength);
      while(i<arrayLength) {
        String KLUBID[i] = nested[i][F("KLUBID")].as<String>();
        Serial.print (KLUBID[i]);
        i++;
      }        
      

    

    
    } else {
      Serial.print("Error code: ");   // Else print http error code
      Serial.println(httpResponseCode);
    }

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