Adafruit_SSD1306 VS ArduinoJson

You can compare it with Adafruit's Library

I'm building a travel router with OpenWRT on a spare Pi 3B+ and I want to add an SSD1306 based oled display plus a shutdown button but both of them require the RPi.GPIO library.

The selection is important. Provision of details is also important. which is why I ask you to supply the code you are actually using (formatted text) - how can we possibly know that the location you found an example program (or the library) is the same one that we find online and thus the example is the same? This is highlighted by the fact that the name of the program you are using is similar to but not the same as the ones in what looks like the official Adafruit github repository https://github.com/adafruit/Adafruit_SSD1306. Maybe it is, maybe it isn't the point is that this ambiguity can easily be resolved if you provide the code you are using.

Is the line (36 here) that I'm focusing on. In the original example, 'PB4, PA8' are replaced with '&Wire', to use the wire.h library default pins on the board. I've tried a fair few combinations of pins and references in the program, which is otherwise unmodified apart from the lines referring to using the serial port to talk to the computer being removed (lines 61 through 67), as the DFU bootloader can't talk using serial (as I have rather time consumingly learned already).

Here is the test sketch on GitHub for the library I used.

I used adafruit ssd1306 library to control the display, donut rendering was written myself and based on the math outlined here, mostly the math around the rotation matrices. (I didn't implement the z-buffer / lighting code)

Nice I got it fixed with my first open source contribution: https://github.com/adafruit/Adafruit_SSD1306

#include //library for transceiver (nrf24l01+ PA+LNA) https://github.com/nRF24/RF24 #include #include #include //library for multiplexer (74HC4067DB) https://github.com/stechio/arduino-ad-mux-lib using namespace admux; #include //library for display (SSD1306 128x64) https://github.com/adafruit/Adafruit_SSD1306 #include //library for I2C const int sig = A3; //signal pin const int s0 = 2; //address pin 0 const int s1 = 3; //address pin 1 const int s2 = 4; //address pin 2 const int s3 = 5; //address pin 3 const int up1pin = 1; //foward left motor const int down1pin = 0; //backwards left motor const int up2pin = 3; //foward right motor const int down2pin = 2; //backwards right motor const int modifierpin = 4; //pwm speed modifier const int trimmerpin = 5; //pwm trimmer const int navlightpin = 6; //navigation lights const int intlightpin = 7; //interior lights const int extlightpin = 8; //exterior lights const int camerapin = 9; //fpv camera const int autoModepin = 10; //autonomous mode const int CE = 9; //radio CE pin const int CSN = 10; //radio CSN pin const byte address[5] = "00001"; //pipe address float latFromSerial; //parsed lattitude from serial input float lonFromSerial; //parsed longitude from serial input float batteryVoltage; //calculated battery voltage float batteryPercentage; //estimated battery charge int timer; //millis timer const int waypointSize = 50; //number of waypoints const PROGMEM float waypoint[waypointSize][2] = { //waypoints for autoMode() {51.966571, 6.2743379}, {51.966772, 6.2744777}, {51.96699149689901, 6.274366197893084}, {51.9671527562416, 6.274120865412113}, {51.96729645199409, 6.273423270736089}, {51.96743080331666, 6.272665240634041}, {51.96754042621848, 6.271857581899409}, {51.96776236209548, 6.270915330645548}, {51.96798193464908, 6.270221004668555}, {51.96828516667115, 6.269413032485236}, {51.96872940066316, 6.268397202672209}, {51.9690764880844, 6.267825125563484}, {51.96951599079974, 6.267264642338533}, {51.97011340024988, 6.266554277598022}, {51.97066084143675, 6.265542763068586}, {51.97101162702417, 6.264465224751552}, {51.97133799766154, 6.263262306712254}, {51.97164036068298, 6.262353231049387}, {51.97207885573615, 6.261205467922246}, {51.97247264722145, 6.260387048788263}, {51.9730446081463, 6.259285804638093}, {51.97348333946684, 6.258252773125921}, {51.97383500264349, 6.257083089055559}, {51.97411491189212, 6.255751674816601}, {51.97421125024911, 6.254641997085617}, {51.97428144275973, 6.253337927743205}, {51.97438642575778, 6.252258957953291}, {51.97461230120062, 6.251185555711}, {51.97496391672023, 6.250073663806153}, {51.97535356652884, 6.249136612734796}, {51.97593199219659, 6.247849009012851}, {51.97673996614692, 6.246219928264511}, {51.97759975319016, 6.244774079377116}, {51.97970812227523, 6.24269840869726}, {51.98056951741261, 6.241148196857345}, {51.98138148466968, 6.238582344717527}, {51.98226488661611, 6.236909516229776}, {51.9828880442564, 6.236150123494202}, {51.98356664827293, 6.235581737840659}, {51.9846292540927, 6.235086763643169}, {51.98620084359441, 6.234541602496764}, {51.9869680375904, 6.233970146843246}, {51.9884155464398, 6.232522126238424}, {51.98950934373955, 6.231079775783453}, {51.99067711020479, 6.229346290429132}, {51.99142243067518, 6.228071305330573}, {51.99218280844037, 6.226417272538562}, {51.99276345055314, 6.224660968088269}, {51.9928317367713, 6.22340383146351}, {51.99303408040588, 6.222658471539628}, }; int waypointCounter = 0; struct values{ //structure for control values bool up1; bool down1; bool up2; bool down2; int trimmer; int modifier; bool navlight; bool intlight; bool extlight; bool camera; bool autoMode; float targetLat; float targetLon; }; struct info{ //structure for answer from boat int autoMode; int battery; int boatHeading; float boatSpeed; int targetDistance; int targetHeading; }; struct values control; //control values struct info answer; //answer from boat Mux mux(Pinset(s0, s1, s2, s3)); //multiplexer object Adafruit_SSD1306 display(128, 64, &Wire, -1); //display object RF24 radio(CE, CSN); //wireless object void setup() { radio.begin(); //start radio service as transmitter radio.setPALevel(RF24_PA_MIN); //transmission power radio.setDataRate(RF24_250KBPS); //data rate radio.enableAckPayload(); //enable ack payloads radio.setRetries(5,5); //delay, count radio.openWritingPipe(address); //set pipe address radio.stopListening(); //stop listening Serial.setTimeout(10); //set timeout for waiting for incoming data Serial.begin(115200); //set serial baudrate if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { Serial.println(F("SSD1306 allocation failed")); for(;;); // Don't proceed, loop forever } delay(2000); //allow startup of display display.clearDisplay(); //clear the display display.setTextSize(1); //standard 1:1 pixel scale display.setTextColor(WHITE); //set white text display.cp437(true); //use full 256 char 'Code Page 437' font control.targetLat = 51.966451; //default target lattitude control.targetLon = 6.274279; //default target longitude } void loop() { if(millis() - timer >= 100){ //activate every 100 milliseconds timer = millis(); //new timestamp mux.signalPin(sig, INPUT_PULLUP, PinType::Digital); //read all digital switches control.up1 = !mux.read(up1pin); control.down1 = !mux.read(down1pin); control.up2 = !mux.read(up2pin); control.down2 = !mux.read(down2pin); control.navlight = !mux.read(navlightpin); control.intlight = !mux.read(intlightpin); control.extlight = !mux.read(extlightpin); control.camera = !mux.read(camerapin); control.autoMode = !mux.read(autoModepin); mux.signalPin(sig, INPUT, PinType::Analog); //read the analog potentiometers control.modifier = mux.read(modifierpin); control.trimmer = mux.read(trimmerpin); /* if(Serial.available()){ //get target location from serial input latFromSerial = Serial.parseFloat(); //read lattitude lonFromSerial = Serial.parseFloat(); //read longitude if(latFromSerial != 0) //only non zero values control.targetLat = latFromSerial; if(lonFromSerial != 0) //only non zero values control.targetLon = lonFromSerial; } */ control.targetLat = waypoint[waypointCounter][0]; //set target waypoint lattitude control.targetLon = waypoint[waypointCounter][1]; //set target waypoint longitude if(answer.autoMode == 1 && waypointCounter < waypointSize-1) //set next waypoint waypointCounter++; if(control.autoMode && control.camera) //if autoMode is activated use trim potmeter and camera button to override waypoint selection waypointCounter = map(control.trimmer, 0, 1023, 0, waypointSize-1); if(radio.write(&control, sizeof(control))){ //send control values Serial.println(F("Data sent successfully")); if(radio.isAckPayloadAvailable()){ //do we get an answer back? radio.read(&answer, sizeof(answer)); //read answer batteryVoltage = (batteryVoltage+(answer.battery*15.0/1023.0))/2.0; //calculate battery voltage (measured as 1/3th with voltage divider) batteryPercentage = (batteryVoltage-11.5)/(13.0-11.5)*100; //estimate battery charge remaining answerToDisplay(); //put all info on oled display } else{ Serial.println(F("Message received but no answer...")); display.clearDisplay(); //display message for no answer from boat display.setCursor(0, 1); display.print("RC Boat: no answer"); display.display(); } Serial.print((control.targetLat)); Serial.print((" ")); Serial.println((control.targetLon)); } else{ Serial.println(F("Data sending failed")); //display message for no connection to boat display.clearDisplay(); display.setCursor(0, 1); display.print("RC Boat: no contact"); display.display(); } } } void answerToDisplay(){ //function for putting answer from boat on display display.clearDisplay(); display.setCursor(0, 1); display.print("RC Boat: connected!"); display.setCursor(0, 15); display.print("Battery: "); display.print(batteryPercentage, 0); display.print("% "); display.print(batteryVoltage, 1); display.print("V"); display.setCursor(0, 29); display.print("Course: "); display.print(answer.boatHeading); display.print((char)248); display.print(" "); display.print(answer.boatSpeed, 1); display.print("km/h"); display.setCursor(0, 43); display.print("AutoMode: "); if(control.autoMode == 1) display.print(answer.autoMode); else display.print("off"); display.print(" "); display.print(waypointCounter); display.setCursor(0, 57); display.print("Target: "); display.print(answer.targetDistance); display.print("m "); if(answer.targetHeading >= 0) display.print("+"); display.print(answer.targetHeading); display.print((char)248); display.display(); }

That's not an LCD screen, it is an OLED. You'll need to use the SSD1306 library (that is the name of the controller embedded in the screen). https://github.com/adafruit/Adafruit_SSD1306

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/.