Base64 image string to json about arduinojson HOT 3 CLOSED

Hi @BoostedPenguin,

What does the ArduinoJson Troubleshooter say?

Best regards,
Benoit

from arduinojson.

I can fix the overflow by following the Troubleshooter tips, however I cannot fix the garbage output string. If I hardcode a base64 string in the program itself, without capturing an image and then converting it to base64 the output string is correct. However, if I encode a captured image from the CAM it always produces garbage output.

Printing the value of the encoded string is always correct base64, but when I provide it to jsonDocument the output always goes wrong at a specific place:

/9j/4AAQSkZJRgABAQEAAAAAAAD
/9j/4AAQSkZJRgABAQEr

`

JsonDocument jsonDocument;

Serial.println("Capturing image...");

camera_fb_t *fb = nullptr;

// Skip 3 frames :)
for (int i = 0; i < 5; i++)
{
    fb = esp_camera_fb_get();
    esp_camera_fb_return(fb);
    fb = nullptr;
}

fb = esp_camera_fb_get();

Serial.println("Captured");

if (!fb)
{
    return;
}

String encoded = base64::encode(fb->buf, fb->len);

Serial.println("Encoded...");
// Release the frame buffer
esp_camera_fb_return(fb);
Serial.println("Released");

Serial.println(encoded);
jsonDocument.clear();
jsonDocument["image"] = encoded;
jsonDocument["email"] = "TestEmail";
jsonDocument["deviceName"] = "MyDevice1";
String jsonBody;

jsonDocument.shrinkToFit(); // optional

Serial.println("Serializing");

serializeJson(jsonDocument, jsonBody);
Serial.println("Overflow: " + String(jsonDocument.overflowed()));

Serial.println(jsonBody.substring(0, 80));

Serial.println("Generating HTTP request");

`

from arduinojson.

If I hardcode a base64 string in the program itself, without capturing an image and then converting it to base64 the output string is correct. However, if I encode a captured image from the CAM it always produces garbage output.

This is the sign of a dangling pointer.
What did the Troubleshooter say?

from arduinojson.