OV2640 Camera Powerdown

Other Hardware Sensors
1

I have been working on a project that adds a LoRa module to the small SEEED ESP32S3 Sense board which has an OV2640 camera and SD card.

The images taken by the camera can be saved to SD and the transferred via LoRa to a remote receiver, there would be wildlife or security monitoring applications.

A low deep sleep current is important for a battery powered application and the ESP32S3 and LoRa part has a deep sleep current of 12uA.

The camera has an advertised deep sleep current of 3mA, which is about right when the camera is first powered up. You could probably live with 3mA, solar panel on the battery etc.

However if you use the camera, there does not appear to be any way of getting it back into the initial power on state and the 'deep sleep' current is 90mA.

The OV2640 appears to be configured via I2C, but an I2C scanner does not detect it.

The ESP32CAM, which also uses the OV2640, has a GPIO turning off the regulators that power the camera and that board does then have a deep sleep current of circa 2.5mA.

Any ideas on how to reduce the 90mA the OV2640 consumes, you would think if it can be configured for use, you could also reverse the configuration by putting all the registers back to the power up state.

2

Why not just periodically power down the entire SEEED board + radio? The Adafruit TPL5110/5111 power timers seem ideal for this.

3

Sure I could do that or in my case I would prefer a more flexible approach and use a circuit based on a PCF8563 RTC. That circuit would connect to the host via I2C and you can then programatically set sleep times of seconds, minutes, hours or days. Deep sleep current is 2uA.

However it would be good for some applications if you did not need to power down the board all the time (to kill the 90mA) but perhaps just pause it in light sleep mode.

4

Hello srnet --

Storing images to SD then using LoRa to transmit them elsewhere seems to me a mismatch. As the name LoRa implies, it's long range, but it's relatively slow. If the distance isn't great, you might be better served by 2.4 GHz WiFi.

5

And WiFi is very short range and of little use in a lot of applications.

LoRa devices can be fast too, you can transfer a 64K image in a little over 2 seconds.

6

Its entirely logical.

You may have an application where you want to remotely monitor or record something by taking camera images.

You maybe dont want to loose the images, so obviously you save them to SD.

If the comms are good you transfer them over RF of some means.

7

Did you make any progress with this topic?
I would also like to be able to powerdown the OV2640 camera on my SEEED ESP32S3 Sense.

8

You cannot.

The hardware design of the SEEED ESP23S3 sense board just does not allow for powerdown, which is completly daft.

Seeed should redesign their product, not difficult, and they may then have a product that is useful.

9

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