Questions tagged [json]

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2 votes
1 answer
155 views

RFID reading function returning null

I have a function that reads an RFID card and returns the RFID string. The function reads the string well but I am using the ArduinoJson library to generate JSON. This is the function that I am using ...
2 votes
1 answer
230 views

ArduinoJson- unexplained '.size()' behaviour

I'm using an ESP8266, ArduinoJson v6.21.5. PlatformIO, and Vscode. The config file is saved and read correctly to the ESP8266's flash: { "gen_pubTopic": [ "DvirHome/Messages&...
1 vote
2 answers
454 views

Need help with parsing NWS JSON weather alerts causing reset on ESP8266

I'm trying to parse the JSON string from the National Weather Service Alerts and am encountering a problem where the code can't parse the value and the device auto-resets. I've used this code before ...
1 vote
1 answer
152 views

ArduinoJson reading `null` from Serial

I have a setup that reads from serial when I sense that there is something to be read (and always assume that what is sent to the arduino is valid json): void setup(){ Serial.begin(9600); ...
1 vote
1 answer
277 views

How to add one JsonDocument to another in ArduinoJson

I'm utilizing this json library: https://arduinojson.org/ I am attempting to write a function that creates a response object, and wraps an already built json document: void sendResponse( ...
2 votes
1 answer
250 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....
2 votes
0 answers
136 views

Using HTTPClient with ESP not working

I have a program running on an esp8266 that attempts to fetch json data from an HTTPS endpoint that is hosted on aws amplify (data comes from a next.js app). I can retrieve the data correctly when I ...
2 votes
2 answers
244 views

ArduinoJson library parsing error

I am trying to retrieve JSON mqtt message I received in ESP32. void mqttMsgCallback(char* topic, byte* payload, unsigned int length) { payload[length] = '\0'; String _message = String((char*)...
1 vote
0 answers
49 views

esp8266 r1 mini stops serial print during execution

The setup includes an WEMOS/ESP8266 R1 mini compatible board, a DHT11, a photo resistor and a magnetic reed. The libs used are: #include <ESP8266WiFi.h> #include <PubSubClient.h> #include &...
0 votes
1 answer
5k views

Serial communication from Arduino to ESP8266 NodeMCU works, but from NodeMCU to Arduino isn't working

My circuit connection is like: (I am following this tutorial) Code uploaded to Arduino: #include <SoftwareSerial.h> #include <ArduinoJson.h> SoftwareSerial s(5,6); void setup() { s....
3 votes
1 answer
600 views

how to transfer json to string?

I am getting a json object from aws iot MQTT. Assuming that json from aws is {status:opened}. Here is my code. #include <ArduinoJson.h> void messageHandler(char *topic, byte *payload, unsigned ...
-1 votes
1 answer
485 views

Best way to get JSON from struct vector class

I have a vector which consist of a struct, see below: struct FileInformation { String name; size_t filesize; }; std::vector<FileInformation> FileInformations; How do I get JSON ...
1 vote
1 answer
1k views

How to convert serialized JSON string back to JSON object?

How to convert JSON String for example {"f0":100,"f1":100,"f2":100} It is what I get from my esp01 side from I2C communication Now I want it to get it back to my Arduino ...
1 vote
1 answer
220 views

Reading & writing a configuration file on an Adafruit Circuit Playground Express

I would like to store an application's configuration in a file stored on the Circuit Playground Express (CPX) flash. The application itself needs to be able to update the configuration file. Things I ...
0 votes
1 answer
669 views

How to allow cross-domain requests with ESP8266WebServer.h ? - CORS policy: Access-Control-Allow-Origin

With an nodeMCUv2 I want: to start a wifi server with ESP8266WebServer.h serve a root html page which will interact with the ESP and fetch external data Issue: CORS policy: No 'Access-Control-Allow-...
0 votes
2 answers
641 views

ArduinoJSON :: How to determine Array's size in a DOC conatinaing not only Arrays

Parameter file containing MQTT topics as shown below, is read into StaticJsonDocument<1250> DOC variable. Size of some groups may differ between MCU's, for example sub_topics_win may contain ...
1 vote
0 answers
90 views

Inconsistant compilation error

It is s a bit complicated to ask such question, but what may be the reason that one time compilation passes and other fails without any changes in code? surely debugging this way is very hard (one ...
0 votes
1 answer
270 views

Determining ArduinoJSON document size based on file size

I'm trying to effectively allocate a doc's size, based on the size of the file saved in flash of ESP8266. Is there a way? For example: file.size() X 1.5
1 vote
1 answer
1k views

Arduino create Json Array with double values and 2 decimal point

How i can create a Json Array with double values and 2 decimal point using the ArduinoJson Library? https://arduinojson.org/v6/how-to/configure-the-serialization-of-floats/ In the folowing small ...
-1 votes
1 answer
942 views

Use of ESPAsyncWebServer.h with ArduinoJson version 6 for Master-Client transactions

I want to communicate two (2) ESP32's via Json commands using ESPAsyncWeb.h. The master should have specific operations to execute and respond to the client, and the client should be able to send ...
-1 votes
1 answer
997 views

Can't read JSON data from client (webpage) with Arduino Leonardo ETH

I'm reading a digital pin and count how many times that pin is enable, after that the data is sent in JSON format. All is working well till here. But I want to introduce a value from webpage to ...
0 votes
1 answer
2k views

Parsing JSON response from Stream

I want to parse JSON response from a GET Request. I do this usually by using a String variable to store the response and later parse this string using ArduinoJSON library like shown below: #include &...
1 vote
2 answers
5k views

Parse a large json response with ESP8266

I'm doing a project where my Arduino uses an external ESP8266 wifi module (with AT firmware) to send http requests and receive server response. I'm trying to get an NBA scoreboard, and here's what my ...
1 vote
2 answers
2k views

Guru Meditation Error: Core 1 panic'ed (Interrupt wdt timeout on CPU1)

Heres my code: #include <WiFi.h> #include <HTTPClient.h> #include <ArduinoJson.h> const char* ssid = "wifiSSID"; const char* password = "wifiPassword"; int ...
1 vote
1 answer
670 views

Custom library for Arduino to encode and decode JSON Web Tokens

So I have been recently been trying to create a library for Arduino to encode and decode JSON Web tokens(JWT) using HMAC-SHA256. For those unfamiliar, JWT has 3 parts - The header, body and signature....
1 vote
1 answer
55 views

ESP8266 AutoConnect ACSelect selection index

I'm trying to retrieve the current selected/saved index of my AutoConnectSelect Right now i'm creating a type that reads the saved json: AutoConnectSelect& bright = settingsAux["...
1 vote
1 answer
446 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
0 answers
61 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 ...
3 votes
1 answer
6k 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&...
1 vote
1 answer
3k 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
0 answers
67 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,...
0 votes
1 answer
631 views

Reading and Writing to a JSON File on the Desktop from Arduino?

I'm fairly new to Arduino. I'm working on a project where I'm making HTTP requests using a python code and this lets me read and write to a JSON file on my desktop. I have an Arduino with sensors that ...
0 votes
1 answer
603 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. ...
1 vote
0 answers
93 views

JSON Parser fails because number of bytes is being sent

Sorry I am new with this. I am trying to read a JSON response from my website using an ESP8266, but it keeps failing. I am using the following code: WiFiClientSecure httpsClient; //Declare object ...
3 votes
2 answers
228 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/ ...
0 votes
1 answer
484 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
1 answer
320 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<...
1 vote
2 answers
587 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 ...
2 votes
0 answers
2k 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 ...
1 vote
1 answer
490 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 vote
1 answer
351 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 votes
1 answer
181 views

ArduinoJson is not adding string to JsonObject. ArduinoJson broken?

So I've got this code String GetTimeString(){ strftime(dateArray, 100, dateFormat, getTimeInfo()); dateString = String(dateArray); Serial.println(dateString); return ...
0 votes
1 answer
3k views

Reading a json file from SPIFFS and displaying the info it contains on an embedded web page

I am working on a smart IR receiver that reads an IR signal, decodes it and saves that decoded info in a json file stored on the NodeMCU's SPIFFS. This info is then displayed on the embedded web ...
-2 votes
1 answer
4k views

What is the maximum size of Static Json Document in Arduino JSON?

I'm trying to do serial communication between Arduino mega and a esp8266, and having issues with determining the size of the JSON document. I have read that the receiver buffer size should be greater ...
2 votes
2 answers
11k 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 ...
1 vote
0 answers
744 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 vote
1 answer
160 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 vote
2 answers
581 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 vote
1 answer
1k 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
1 answer
854 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 ...