Hi.

I think that is happening because GPIO16 is internally connected to a pull-up resistor. See it here: https://i1.wp.com/randomnerdtutorials.com/wp-content/uploads/2020/03/ESP32-CAM-AI-Thinker-schematic-diagram.png?ssl=1

Additionally, when the PIR motion sensor detects motion, its state stays HIGH for a few seconds. For the PIR sensor we use, it’s usually 7 seconds, if I’m not wrong.

Are you printing in the Serial Monitor the state of the PIR sensor? Does it change?

When using a PIR motion sensor with the ESP32, it is better to use interrupts instead.

A few days ago, I’ve experimented with interrupts on the ESP32-CAM pins, here’s what I found:
GPIO 13: works well
GPIO 15 : works with inverted logic
GPIO 12: Guru meditation error when it gets a HIGH signal
GPIO 14: works well
GPIO 2: works well
GPIO 4: doesn’t work as expected.

If you don’t need to use the microSD card, you’ll have other pins to experiment with the PIR sensor.

I hope this helps.

Regards,
Sara

Hello Mam, Thank you for the detailed response. I tried various pins as recommended by you and using Interrupt. But now I am getting GuruMeditation error and Camera probe error. It might be that I am doing some mistake in implementing Interrupt.
Code: https://pastebin.com/p4KyusaQ
Serial Monitor:https://imgur.com/FxcTjs3
Serial Monitor:https://imgur.com/2BLvBEy
Thanks

Hi.

I spend the last couple of hours trying to implement your project, but no luck. I was not able to use interrupts and the microSD card at the same time.

I’ve implemented the same project, but saving the photos in SPIFFS. Here’s the code:https://pastebin.com/fGW8fXdA
With the ESP32-CAM you need to implement interrupts as follows (in this case in GPIO 14):

esp_err_t err = gpio_isr_handler_add(GPIO_NUM_14, &detectsMovement, (void *) 1);
  if (err != ESP_OK) {
  Serial.printf("handler add failed with error 0x%x \r\n", err);
}
err = gpio_set_intr_type(GPIO_NUM_14, GPIO_INTR_POSEDGE);
  if (err != ESP_OK) {
  Serial.printf("set intr type failed with error 0x%x \r\n", err);
}

And the callback function:

static void IRAM_ATTR detectsMovement(void * arg) {
  Serial.println("Motion Detected");
  takePicture = true;
}

I tested the example I’ve sent you with a PIR motion sensor on GPIO 14 and it worked well.

I hope this helps.

Regards,
Sara

Dear Mam,
Thank you, Mam, for your help. I really appreciate. And I tried the sketch, it is working fine. Thank you so much, Mam.

Hello Mam, as I am new to the SPIFFS file system, and as per me, after a certain limit the flash will be full and I have to delete the files.

So, is it possible within the code, that after sending an email with the attachment we can delete that file from the flash?

I was trying this simple sketch:

#include "SPIFFS.h"

void setup() {

Serial.begin(115200);

if (!SPIFFS.begin(true)) {
Serial.println("An Error has occurred while mounting SPIFFS");
return;
}
Serial.println("\n\n---BEFORE REMOVING---");
listAllFiles();

SPIFFS.remove("/photo.jpg");

Serial.println("\n\n---AFTER REMOVING---");
listAllFiles();

}
void listAllFiles(){
File root = SPIFFS.open("/");
File file = root.openNextFile();

while(file){

Serial.print("FILE: ");
Serial.println(file.name());
Serial.print(file.size());
Serial.println(" bytes");
file = root.openNextFile();
}
}

void loop() {}

Please correct me if I am wrong, as it might be a basic question.

Thanks

Hi.
I think that should work.
But if you overwrite the same photo name, I don’t think you’ll have memory problems.
Regards,
Sara

OK, and I found this link https://github.com/pellepl/spiffs/wiki/FAQ#how-long-will-my-spi-flash-live and as I understood, it says if we do one write per second than the flash can survive for 355 days and I think this is sufficient for this device.
Thanks a lot, Mam. 

Hi.
Thanks for sharing that link.
It’s very informative.
Regards,
Sara