ESP32 drawjpg from array not working

[nikisalli]

hi :) i'm having an issue with both drawJpg() functions on esp-wroom-32. it looks like all the chunks of the image are rendered in the exact same spot and i couldn't figure out why because with your jpeg decoder library it works so my array can't be wrong. maybe incorrect offset calculation for the chunks? this is the code i'm using. you can see i included both libraries and at the last line i called the jpg displayer.

#include <WiFi.h>
#include <WiFiMulti.h>
#include <HTTPClient.h>
#include <SPI.h>
#include <TFT_eSPI.h>
TFT_eSPI tft = TFT_eSPI();
#include <TFT_eFEX.h>   
TFT_eFEX  fex = TFT_eFEX(&tft);

#define USE_SERIAL Serial

WiFiMulti WiFiMulti;
int pic = 1;

uint8_t PicArray[80750] = {0}; //Array for picture make sure under 15K

void setup() {
  pinMode(23, OUTPUT);
  digitalWrite(23, LOW);
  pinMode(27, INPUT);

  USE_SERIAL.begin(115200);

  tft.init();
  tft.setRotation(1);
  tft.fillScreen(TFT_BLACK);
  tft.setTextColor(ILI9341_GREEN);
  tft.setCursor(15, 30);
  tft.setTextSize(2);

  USE_SERIAL.println();
  USE_SERIAL.println();
  USE_SERIAL.println();

  digitalWrite(23, HIGH);

  //###################################################################
  WiFiMulti.addAP("xxxxxxxxxxxxxx", "xxxxxxxxxx");
  //####################################################################
}

void loop() {
  if (pic > 8){
    pic = 1;
  }
  tft.fillRect(11, 26, 240, 24, 0x0000);
  tft.drawRect(11, 26, 240, 24, ILI9341_RED);
  tft.setTextColor(ILI9341_GREEN);
  tft.setCursor(15, 30);
  tft.setTextSize(2);
  tft.print("Downloading Pic:" + String(pic));
  USE_SERIAL.println("Downloading Pic:" + String(pic));
  // wait for WiFi connection
  if ((WiFiMulti.run() == WL_CONNECTED)) {
    GetPic();
  }
  pic++;
  delay(10000);
}

void GetPic() {
  HTTPClient http;
  long totalSize = 0;
  boolean chone = 1;
  // configure server and url update based on your URL
  http.begin("http://www.meteosatonline.it/riduce/nuova/ultima.jpg");  //update based on your URL
  //http.begin("http://10.16.10.11:8980/tempgr/ac/BaboonL.jpg");
  // start connection and send HTTP header
  long httpCode = http.GET();
  if (httpCode > 0) {
    // HTTP header has been send and Server response header has been handled
    USE_SERIAL.printf("[HTTP] GET... code: %d\n", httpCode);

    // file found at server
    if (httpCode == HTTP_CODE_OK) {

      // get lenght of document (is -1 when Server sends no Content-Length header)
      long len = http.getSize();

      // create buffer for read
      uint8_t buff[2048] = { 0 };

      // get tcp stream
      WiFiClient * stream = http.getStreamPtr();

      // read all data from server
      while (http.connected() && (len > 0 || len == -1)) {
        size_t size = stream->available();
        if (size) {

          int c = stream->readBytes(buff, ((size > sizeof(buff)) ? sizeof(buff) : size));
          memcpy (PicArray + totalSize, buff, c);
          totalSize = totalSize + c;

          if (len > 0) {
            len -= c;
          }
        }

        yield();
      }
      USE_SERIAL.print("[HTTP] connection closed or file end.\n");

    }
  } else {
    USE_SERIAL.printf("[HTTP] GET... failed, error: %s\n", http.errorToString(httpCode).c_str());
  }

  http.end();

  USE_SERIAL.println("TotalS:" + String(totalSize));

  USE_SERIAL.print("First 10 Bytes: ");
  for (int ipt = 0; ipt < 11; ipt++) {
    USE_SERIAL.print(PicArray[ipt], HEX);
    USE_SERIAL.print(",");
  }
  USE_SERIAL.print("\nLast 10 Bytes : ");
  for (int ipt = 10; ipt >= 0; ipt--) {
    USE_SERIAL.print(PicArray[totalSize - ipt], HEX);
    USE_SERIAL.print(",");
  }
  USE_SERIAL.println("");
  uint8_t scale = (uint8_t)JPEG_DIV_2;
  fex.drawJpg(PicArray, sizeof(PicArray), 0, 0);
}

[Bodmer]

I tried your code and it worked fine fetching small images (<40kbytes) from a server.

The image you are trying to load is far too big for the ESP32 RAM so I am surprised it does not crash. Try with smaller images.

[nikisalli]

Yes, in the meantime i solved the problem and found smaller size images from a different server so that they can fit in ram. I was able to display images up to 80kb in size. awesome!