Questions tagged [json]

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votes
2answers
91 views

Understanding ArduinoJson capacity calculation assistant

I am trying to figure out how ArduinoJson capacity can be calculated, therefore I came by the Assistant web application developed by the developer of the library https://arduinojson.org/v6/assistant/ ...
3
votes
1answer
239 views

Getting all data of my JSON object from Serial.read() at once

I'm new to Arduino and I'm building a project that fetches data from a website (using ESP8266) and then transfers them to my Arduino UNO via serial port. Data coming from ESP8266 every 20s - [{"x&...
3
votes
2answers
499 views

Serial data affected by interrupt

In my recent project, I have done everything means capture serial data and split it out in proper form. Until now everything is fine. But when I add another portion of code which contains Interrupt. ...
2
votes
2answers
9k views

NodeMCU (Arduino IDE) 'DynamicJsonBuffer' was not declared in this scope

#include <Arduino.h> #include <ESP8266WiFi.h> #include <ESP8266WiFiMulti.h> #include <ArduinoJson.h> #include <ESP8266HTTPClient.h> #define USE_SERIAL Serial ...
2
votes
1answer
2k views

ArduinoJSON v6 - Passing buffer as function parameter

I'm new to ArduinoJSON - so perhaps it is a newbie's question.... but I wish to pass a StaticJsonDocument into a function as a parameter ( later on it should be implemented in a library ). exmaple ...
2
votes
1answer
4k views

How to post JSON data from Arduino?

I want to post data that I'm getting from the sensor every 5 seconds to my application in JSON format. Initially, I'm getting data as int and converting into String. For example: if data=15, it is ...
2
votes
1answer
47 views

rfid reading function returning null

I have a function that reads rfid card and return rfid string. Function reads string well but. I am using ArduinoJson libray to generate json . this is the function that i am using to read rfid cards. ...
2
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0answers
425 views

Reading JSON from Arduino over serial in python and writing to a JSON file on computer

I'm fairly new to Arduino so I used a sample code before integrating this into my main code. I'm printing my value in a JSON format over serial. My Arduino outputs this and the python receives this ...
2
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0answers
2k views

Convert String data To char Array in Arduino

I'm able to get json data and storing in String object, now i want to convert string into Char Array for parsing json data I'm tried with this code, but it is not responding String data = http....
1
vote
2answers
140 views

Unexplained behavior of char array after using `deserializeJson`

I'm using RF24 library to send messages between 2 MCU's : 1) ESP8266 (no Wifi, same code can be compiled to any Arduino board) 2) pro-Micro. Message is sent in JSON format, while using ArduinoJSON ...
1
vote
1answer
2k views

publish json data to mqtt

I am trying to publish JSON data to mqtt with following code snippet #include <Arduino_JSON.h> JSONVar data; data["temperature"] = temperature; data["humidity"] = humidity; data["pressure"] = ...
1
vote
1answer
255 views

json format in esp32 with arduino json

I am using an ESP32 module for bluetooth connection and scaning wifi network. But I cannot format the json using arduinojson library in the way I want. void scanWifiNetworks() { //creating json ...
1
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1answer
86 views

How to properly handle the Arduino String

I've read that the Arduino String is bad as it causes memory fragmentation, so I try to avoid them mostly. But I still have some occurences where I'm not quite sure if they are ok after all. The first ...
1
vote
1answer
82 views

ESP8266 Arduino Json object array deserialisation into struct

I'm trying to de serialize an array of JSON objects into a struct. Following the instructions given by the Arduino JSON assistant, I managed to produce this helper function: void JsonPreprocessor(...
1
vote
1answer
87 views

Large number into variable

Probably something easy but I’ve not resolved it. I’m extracting data from a JSON string and all the values are correct accept for two. They are referring to two date time values and are in ...
1
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1answer
415 views

Serialize JSON as response to HTTP request

I'd like my ESP8266 to provide some JSON endpoints. I want to use ArduinoJson for serialisation. While this works in general if I serialize into a String and return this String afterwards, I was ...
1
vote
1answer
241 views

Sending JSON message to web api via post. Why does HTTP 1.0 versus 1.1 make a difference?

I am sending a message to a web api call every xx seconds. I could not get it to work at all until I changed the header from HTTP 1.1 which is what I was using to HTTP 1.0. Then, it started working. ...
1
vote
2answers
77 views

Problem regarding getting split data of JSON - Another issue

In my recent project, I'm working with Arduino and JSON. I've successfully split the JSON data I want. My JSON data length is fixed. So, I used the length() function and I'm getting the length of my ...
1
vote
1answer
210 views

How send method POST with JSON? Arduino UNO R3 + SIM900

Why is the server side of php not loading any data from arduino? What did I do wrong? String reading="{\"latitude\": 12.983027, \"longitude\": 80.2594}"; mySerial.println("AT+HTTPINIT"); ...
1
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1answer
84 views

How to get full response json SIM900 + Arduino?

void toSerial(int delay_ms) { delay(delay_ms); while(mySerial.available()) { Serial.write(mySerial.read()); } } Serial.begin(9600); mySerial.begin(9600); mySerial....
1
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2answers
182 views

ArduinoJSON: Using a reference to a reference when parsing array of arrays

I started to play around with the ArduinoJson library to parse data I got from one of my APIs (the format of the JSON data I get from my API can be improved for sure, but the software I had to ...
1
vote
1answer
165 views

Arduino Uno with Adafruit CC3000

I am using Arduino Uno with Adafruit CC3000 wifi shield to connect to the internet and get data for Arduino. Everything works fine but I can't figure out how to use HttpClient library. The code is: #...
1
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1answer
7k views

How to pass JsonObject from ArduinoJson to ESP8266WebServer object?

I am learning the ArduinoJson.h library and creating jsonOject: JsonObject& prepareResponse(JsonBuffer& jsonBuffer) { JsonObject& root = jsonBuffer.createObject(); JsonArray& ...
1
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2answers
1k views

POST to server using ESP8266 module- Arduino Uno- AT+ commands

I'm trying to send a set of data in Json format to a server I have set up which has a specific URL and an access token. The server requires a POST command. So my final URL is: http://myurl.com/...
1
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0answers
42 views

How to set maximal execution time of operation

I'm JSON deserializing output from ESP8266 in my Arduino UNO, but when it fails (for some reason every time after it deserializes successfully) the program lags for few seconds and I don't want that ...
1
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0answers
13 views

Changing the order of GUI-elements inside Arduino ESP-Dash-library

I'm trying to add a new item "index" to GUI-elements that are created by using ArduinoJSON and the Vue.js-framework inside the ESP-Dash-library. The library creates GUI-elements like buttons,...
1
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0answers
46 views

RFID data to JSON [closed]

I need to build an attendance and automatic door with RFID. I am using Arduino UNO and ESP8266 . I can build the project with writing the authorised cards by hand. But I want to create a server and ...
1
vote
1answer
85 views

cant read json data esp 32 “parseObject() failed”

hello I am just trying to make Youtube Subscribe Counter with led matrix 32*8 and esp 32 and I had this problem when I trying to get subscribers to count so what is the problem and how I can fix it? `...
1
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0answers
183 views

Edit JSON File on SD Card

I am currently Working on a project, where I save values in a JSON File on an SD Card. The JSON looks something like this: { "ID1":{[[starttime, endtime], [starttime, endtime], [....
1
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2answers
240 views

WiFi.begin doesn't work with ArduinoJson's const char* output

I'm using ArduinoJson to parse a file full of JSON strings that contain the SSID and password for the registered networks. I have a little web interface that runs in soft AP mode so you can scan for ...
1
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0answers
2k views

How to send JSON on a http POST request using an ESP8266?

I'm working on a project aimed on sending alerts via SMS. I signed up for a SMS service that works via HTTP requests (REST standard). I need, then, to send data as JSON, so that their server processes ...
1
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0answers
199 views

Can't print out a field with ArduinoJSON

I'm trying to create a command interpreter. Allowed commands are stored in a JSON document inside SPIFFS. If I send an allowed command, it doesn't print the field associated with that value (end of ...
1
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0answers
39 views

About split string

Sorry my English is poor. I use nodemcu to get a json data. By this String alldata = client.readString(); But it turn this: HTTP/1.1 200 OK Server: nginx Date: Sat, 10 Aug 2019 04:53:16 GMT ...
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0answers
671 views

How to get Json String from URL?

I want to get JSON string from a URL which goes like this https://maps.googleapis.com/maps/api/directions/json?origin=7649+Paseo+Santa+Cruz&destination=SJSU&key=MY_API_KEY and here is my ...
1
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0answers
687 views

ArduinoJSON v6 - return a StaticJsonDocument from a function [duplicate]

I'm reading a stored JSON file from an ESP8266. I wish to return it as a StaticJsonDocument for further use. return it at the end of function was done OK, but I need to assign it for document. #...
1
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0answers
70 views

Reducing json upload time

I'm using an ESP32 WROOM board to capture some data in the field and send it over using arduino json. However, the complete process of sending and receiving confirmation takes up around 12 seconds and ...
1
vote
2answers
1k views

Arduino WiFi Rev2 JSON String

I have been trying to use the WifiNINA library to access the JSON output from the following API using the WifiNINA library and the Arduino Wifi Rev2. This is the code that I have been using (it is an ...
1
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0answers
400 views

Can't parse large json file

For a project I've to parse a big json file. Unfortunately it does not work as expected. Here is the json file: { "data1": "...
1
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0answers
145 views

SerializeJson not working when using softserial

IDE:1.8.8 Board:Arduino UNO When I use the code below, I get result of print like this. { "result": [ { "ID": "01", "Value": [ "2", "1", "13" ] } ] } But when I use SoftwareSerial and in the setup ...
1
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0answers
337 views

append a String on ArduinoJson Object value

I've a json string request coming from server and I convert it into json object StaticJsonBuffer<500> jsonStaticBuffer; JsonObject& root = jsonStaticBuffer.parseObject(String(msg)); ...
0
votes
1answer
55 views

String class summation disappears the right operand

I intend to create a function to jsify sensors' content and save it on a SD-card or send through a http client. Except for the Serial.println's, the function is transcripted below. String jsonificar(...
0
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1answer
40 views

Remove unwanted characters from char type

I'm working on an ESP8266 module that needs to fetch date data from worldtimeapi, everything works fine but the problem is How do I strip of the time field off the datetime JSON response without loop. ...
0
votes
1answer
351 views

Second item in array not gets assigned from struct object, ArduinoJson

I got the below code generated this amazing tool. const size_t capacity = JSON_ARRAY_SIZE(2) + JSON_OBJECT_SIZE(1) + JSON_OBJECT_SIZE(4) + 2*JSON_OBJECT_SIZE(7); DynamicJsonDocument doc(capacity); ...
0
votes
2answers
120 views

Firmware gets stuck at obj.printto(client) in esp32

I am using an ESP32 to capture some data and then sending it over using ArduinoJson. However, sometimes, the firmware gets stuck at the line where it is transmitting data at obj.printTo(client). I ...
0
votes
2answers
6k views

Reading file from SPIFFS in nodemcu using ArduinoJson

#include <ArduinoJson.h> #include <FS.h> /* Set these to desired credentials in runtime */ struct Config { String ssid = ""; String pass = ""; bool hFlag = false; }; void ...
0
votes
1answer
3k views

Arduino JSON foreach loop

I'm trying to extract values using ArduinoJson. The values aren't fixed, therefore I need to use the foreach loop. I'm trying this, but I can't seem to use the values like I could with. root["0"]["...
0
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1answer
298 views

Arduino parsing JSON

I have created an API in Ruby on Rails and it send the following JSON response: {"sun_position":{"altitude":"32.46","azimuth":"223.93"}} I'm able to successfully hit the API and store the response. ...
0
votes
1answer
171 views

Not able to add JSON data to Arduino data

In my recent project, I'm working with Arduino with JSON. I made software on JSON. Now, I want to send data from this software to my Arduino. Serial communication is done between Arduino and JSON. ...
0
votes
1answer
50 views

How to get a specific value from an unknown number of JSON representations?

I am using ArduinoJson and ESP8266HTTPClient. Say I have a DynamicJsonDocument that has an unknown number of entries with information on different persons: [ { "ID": "12345&...
0
votes
1answer
78 views

ArduinoJSON define as extern

My sketch contains 2 .h files. one defines on 1st .h file: #define JSON_SIZE_IOT 400 #define JSON_SIZE_SKETCH 300 StaticJsonDocument<JSON_SIZE_IOT> paramJSON; StaticJsonDocument<...