ArduinoJson VS cJSON

I'm using the library ArduinoJson to storage arts in the ESP8266 memory at JSON format. But, i'm have difficult to storage more than 4 drawings, possibly because i don't know how scale, optimize and manager the memory space.

/******************************************************************* A sample project for making a HTTP/HTTPS GET request on an ESP32 and parsing it from JSON It will connect to the given request, parse the JSON and print the body to serial monitor Parts: ESP32 Dev Board Aliexpress: * - https://s.click.aliexpress.com/e/_dSi824B Amazon: * - https://amzn.to/3gArkAY * * = Affilate If you find what I do useful and would like to support me, please consider becoming a sponsor on Github https://github.com/sponsors/witnessmenow/ Written by Brian Lough YouTube: https://www.youtube.com/brianlough Tindie: https://www.tindie.com/stores/brianlough/ Twitter: https://twitter.com/witnessmenow *******************************************************************/ // ---------------------------- // Standard Libraries // ---------------------------- #include #include // ---------------------------- // Additional Libraries - each one of these will need to be installed. // ---------------------------- #include // Library used for parsing Json from the API responses // Search for "Arduino Json" in the Arduino Library manager // https://github.com/bblanchon/ArduinoJson //------- Replace the following! ------ char ssid[] = "yourSSID"; // your network SSID (name) char password[] = "yourPassword"; // your network key // For Non-HTTPS requests // WiFiClient client; // For HTTPS requests WiFiClientSecure client; // Just the base of the URL you want to connect to #define TEST_HOST "api.openweathermap.org" // Root cert of server we are connecting to // Baltimore CyberTrust Root - Expires 12 May 2025 // (FYI, from a security point of view you should not trust certs from other people, including me!) /*const char *server_cert = "-----BEGIN CERTIFICATE-----\n" "MIIDdzCCAl+gAwIBAgIEAgAAuTANBgkqhkiG9w0BAQUFADBaMQswCQYDVQQGEwJJ\n" "RTESMBAGA1UEChMJQmFsdGltb3JlMRMwEQYDVQQLEwpDeWJlclRydXN0MSIwIAYD\n" "VQQDExlCYWx0aW1vcmUgQ3liZXJUcnVzdCBSb290MB4XDTAwMDUxMjE4NDYwMFoX\n" "DTI1MDUxMjIzNTkwMFowWjELMAkGA1UEBhMCSUUxEjAQBgNVBAoTCUJhbHRpbW9y\n" "ZTETMBEGA1UECxMKQ3liZXJUcnVzdDEiMCAGA1UEAxMZQmFsdGltb3JlIEN5YmVy\n" "VHJ1c3QgUm9vdDCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAKMEuyKr\n" "mD1X6CZymrV51Cni4eiVgLGw41uOKymaZN+hXe2wCQVt2yguzmKiYv60iNoS6zjr\n" "IZ3AQSsBUnuId9Mcj8e6uYi1agnnc+gRQKfRzMpijS3ljwumUNKoUMMo6vWrJYeK\n" "mpYcqWe4PwzV9/lSEy/CG9VwcPCPwBLKBsua4dnKM3p31vjsufFoREJIE9LAwqSu\n" "XmD+tqYF/LTdB1kC1FkYmGP1pWPgkAx9XbIGevOF6uvUA65ehD5f/xXtabz5OTZy\n" "dc93Uk3zyZAsuT3lySNTPx8kmCFcB5kpvcY67Oduhjprl3RjM71oGDHweI12v/ye\n" "jl0qhqdNkNwnGjkCAwEAAaNFMEMwHQYDVR0OBBYEFOWdWTCCR1jMrPoIVDaGezq1\n" "BE3wMBIGA1UdEwEB/wQIMAYBAf8CAQMwDgYDVR0PAQH/BAQDAgEGMA0GCSqGSIb3\n" "DQEBBQUAA4IBAQCFDF2O5G9RaEIFoN27TyclhAO992T9Ldcw46QQF+vaKSm2eT92\n" "9hkTI7gQCvlYpNRhcL0EYWoSihfVCr3FvDB81ukMJY2GQE/szKN+OMY3EU/t3Wgx\n" "jkzSswF07r51XgdIGn9w/xZchMB5hbgF/X++ZRGjD8ACtPhSNzkE1akxehi/oCr0\n" "Epn3o0WC4zxe9Z2etciefC7IpJ5OCBRLbf1wbWsaY71k5h+3zvDyny67G7fyUIhz\n" "ksLi4xaNmjICq44Y3ekQEe5+NauQrz4wlHrQMz2nZQ/1/I6eYs9HRCwBXbsdtTLS\n" "R9I4LtD+gdwyah617jzV/OeBHRnDJELqYzmp\n" "-----END CERTIFICATE-----\n"; */ void setup() { Serial.begin(115200); // Connect to the WiFI WiFi.mode(WIFI_STA); WiFi.begin(ssid, password); Serial.println(""); // Wait for connection while (WiFi.status() != WL_CONNECTED) { delay(500); Serial.print("."); } Serial.println(""); Serial.print("Connected to "); Serial.println(ssid); Serial.print("IP address: "); Serial.println(WiFi.localIP()); //-------- // Checking the cert is the best way on an ESP32 // This will verify the server is trusted. //client.setCACert(server_cert); // If you don't want to verify the server // Unlike the fingerprint method of the ESP8266 which expires frequently // the cert lasts years, so I don't see much reason to ever // use this on the ESP32 client.setInsecure(); } void makeHTTPRequest() { // Opening connection to server (Use 80 as port if HTTP) if (!client.connect(TEST_HOST, 443)) { Serial.println(F("Connection failed")); return; } // give the esp a breather yield(); // Send HTTP request client.print(F("GET ")); // This is the second half of a request (everything that comes after the base URL) client.print("/data/2.5/weather?q=London, UK&appid=[yourOpenWeatherAPI]&units=metric"); // %2C == , client.println(F(" HTTP/1.1")); //Headers client.print(F("Host: ")); client.println(TEST_HOST); client.println(F("Cache-Control: no-cache")); if (client.println() == 0) { Serial.println(F("Failed to send request")); return; } //delay(100); // Check HTTP status char status[32] = {0}; client.readBytesUntil('\r', status, sizeof(status)); if (strcmp(status, "HTTP/1.1 200 OK") != 0) { Serial.print(F("Unexpected response: ")); Serial.println(status); return; } // Skip HTTP headers char endOfHeaders[] = "\r\n\r\n"; if (!client.find(endOfHeaders)) { Serial.println(F("Invalid response")); return; } // This is probably not needed for most, but I had issues // with the Tindie api where sometimes there were random // characters coming back before the body of the response. // This will cause no hard to leave it in // peek() will look at the character, but not take it off the queue while (client.available() && client.peek() != '{') { char c = 0; client.readBytes(&c, 1); Serial.print(c); Serial.println("BAD"); } // // While the client is still availble read each // // byte and print to the serial monitor // while (client.available()) { // char c = 0; // client.readBytes(&c, 1); // Serial.print(c); // } //Use the ArduinoJson Assistant to calculate this: //StaticJsonDocument<192> doc; DynamicJsonDocument doc(1024); //For ESP32/ESP8266 you'll mainly use dynamic. DeserializationError error = deserializeJson(doc, client); if (!error) { float coord_lon = doc["coord"]["lon"]; float coord_lat = doc["coord"]["lat"]; JsonObject main = doc["main"]; float main_temp = main["temp"]; Serial.print("Temp: "); Serial.println(main_temp); Serial.print("Longitude: "); Serial.println(coord_lon); Serial.print("Latitude: "); Serial.println(coord_lat); } else { Serial.print(F("deserializeJson() failed: ")); Serial.println(error.f_str()); return; } } void loop() { makeHTTPRequest(); delay(1500); }

I've logged a github issue, but I'm not convinced I've asked the right questions as I've never had to do anything like this before - am I missing something obvious?

https://arduinojson.org

Also, if you want a nice way to encapsulate data, look at ArduinoJson (https://arduinojson.org/). All your information can be stored as easily identifiable strings in a JSON format. I use it all the time and it removes a lot of the mucking about with figuring out how to parse your data to/from file.

The format is simple JSON data and self explanatory, no binary coding, just simple text, which you can decode using https://arduinojson.org/.

It’s a library he’s including directly. It’s the same.

https://github.com/DaveGamble/cJSON

a quick google search is always easier than a whole reddit post cJSON

This is quite similar to cJSON, although cJSON leans more towards dynamic memory allocation.

If 'de-factoness' (urgh) was measured in GitHub stars, then https://github.com/DaveGamble/cJSON would win.

You often end up with cases where you have to manually call the correct free function for the type you're using, again completely untyped - e.g. if I'm using both sentry and cjson, then my function will ook something like this: