arduino-tvout VS ArduinoJson

NTSC color requires a precise frequency, but if you're fine with just black and white, you can generate NTSC B&W using an Arduino Nano (16 MHz 8-bit processor) and a couple resistors and crocodile clips and an RCA cable. (PAL B&W is similar and also possible.) There are even libraries that make it super easy; I have used this one: https://github.com/Avamander/arduino-tvout (IIRC I needed to fix a couple things to get it to compile).

With Raspberry Pi Picos and their 133 MHz clock rate it seems it's possible to even generate HDMI (and there are youtube videos demonstrating this).

I recently bought a couple crystals to generate the NTSC color subcarrier frequency. The Arduino Nano only has 2 KB of RAM so it's a very tight fit but I'm daydreaming about running a tiny BASIC interpreter on it like to build something similar to an old 80s computer that boots right into BASIC. (There's a small amount of free CPU time between frames and between scanlines, but my calculations indicated that you'd get a fraction of the performance of a C64, especially if you wanted to extend the RAM a bit (which wouldn't be directly addressable)).

The video output is generater through the TVout library (https://github.com/Avamander/arduino-tvout), which works on most Arduino boards (the Pro Minis with an Atmega168 seems to not generate a vide output). To hook it up, combine the SYNC pin (through a 1k resistor) with the VIDEO pin (through a 500 ohm resistor) to get the composite output. Only in black and white though.

I’m assuming it’s the demo from the TVOut library https://github.com/Avamander/arduino-tvout

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/.