TomServo VS ArduinoJson

Since you mention servos, another thing to think about is the whole issue of wasted power when the servos are not moving. Check out my TomServo library and related articles to learn how you can eliminate much of the power wasted on your servos when they are not actually moving.

I used this exact technique on my animatronic eyes project as well. If you would like to avoid reinventing the wheel I have wrapped the technique into an Arduino Library called TomServo if you'd like to check it out.

If you don't want to implement the code for this yourself I wrote the TomServo Arduino Library that actually takes care of all of the details for you. You can install it from within the IDE using the library manager.

*On a related note I wrote an Arduino Library called TomServo that disengages the servos when they aren't actively moving and it re-engages them when a new position has been written to them. The technique I use reduces the power requirements for servo related projects by around ~60% or so. I'm not sure if it would be useful when using a servo controller but if you do use a separate servo controller (as opposed to directly connecting the servo conrtol signals to Arduino pins) I'd love to hear whether it works with them as well if you try it. I could see how it might work great but I could also see how it might not since a lot depends on the design of the controllers themselves.

Servo motors consume a decent amount of power even when they are standing still. Take a look at the Arduino TomServo Library. It places the servos into a high-z state when they aren't moving which cuts the amount of power they consume down to almost nothing! Multiply that by all of the motors you have and that's quite a lot. It will probably eliminate all of the buzzing sounds unless you engage too many of them at once for your power supply.

The TomServo library will detach() the servos when they aren't moving which stops the drive circuitry in the servo from engaging and it greatly reduces the total amount of power being sucked down by your servo motors.

In addition to all of the other great responses here you might want to take a look at using something like the TomServo Arduino Library (shameless plug). I wrote it for a robotic arm project I did many years ago that was battery powered and had 4 servos in it.

It depends. How much torque/resistance will they have? Do they all need to be on at the same time? Can you measure the current used by one of them under the nominal load? Depending on your project you can save a ton of energy if you detach them once they are in position. This might help you out.

TomServo allows you to use less energy in projects that involve servo motors. By stopping the servo from pulling current after it has finished moving you can greatly reduce the amount of power needed for a servo project. Even to the point that you can have a battery powered servo project that won't run out of juice on the first day! 😉

Button Gestures and TomServo! They both need example schematics and directions for use and that is ongoing. I'd love any feedback if you find them useful or think of something that could be improved. And of course contributions from anyone who sees a sharp edge that needs sanding down are more than welcome! 😏

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/.