Video camera recommendation for a ESP32 based robot

Hi,

I am designing a small robot with ESP32 at it's core. It will have two modes of operation - automatic (navigating with an ultrasound and other sensors), and a manual mode (controlled remotely via Wi-Fi). For manual control, I want to have a video camera feed from the robot over Wi-Fi. I've seen several similar projects using OV7670, a cheap camera that is well documented for usage with ESP32. Problem is, this camera requires a ton of pins, and since my robot has a lot of other sensors and modules to control, I don't have that many. I want to do this without port expanders, as these introduce other complexities that I want to avoid.

So, what I'm looking for is a camera module that would work with fewer pins. As I understand it, I2C protocol is too slow for anything but a few frames per second at a very low resolution. Maybe there are some SPI cameras out there? I found some made by ArduCam, but these are very expensive and very bulky. I'm looking for something small (4x4cm at most), cheap (under $15) and that would work using no more than 6 pins on ESP32. I don't need great image quality or 24 frames per second - just enough to make real-time control of the robot possible (maybe 10 fps).

Can you name some options, please?

Easiest, and cheapest, option - use two ESP32's, one for the robot, the other for the camera.

Nigel Goodwin said:

Easiest, and cheapest, option - use two ESP32's, one for the robot, the other for the camera.

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I have thought of that, but battery drain is a consideration, and two ESP's wouldn't fit into this robot anyway... I want to make this with a single microcontroller.

laukejas said:

I have thought of that, but battery drain is a consideration, and two ESP's wouldn't fit into this robot anyway... I want to make this with a single microcontroller.

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In which case you're probably struggling, video cameras need high speed interfaces, which is why they mostly use parallel connections and plenty of pins.

Nigel Goodwin said:

In which case you're probably struggling, video cameras need high speed interfaces, which is why they mostly use parallel connections and plenty of pins.

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Well, yes, but as I said, I don't need 4K at 60 fps here 10 frames per second at, say, 352 x 240 (240p) would be more than enough for navigation. And since there is at least one line of cameras (ArduCam) that interface through SPI, I thought there must be other SPI interface cameras as well, that might incidentally be cheaper and smaller (with a worse quality, that I would be okay with).

P.S. Maybe it would be possible to have another microcontroller (maybe Atmega?) that would handle the video stream and output it via SPI to ESP32? I am not sure if Atmega is up to such task, or if this is at all doable.

laukejas said:

10 frames per second at, say, 352 x 240 (240p) would be more than enough for navigation.

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Which is about 2,500,00 bytes per second - a LOT of data.

Nigel Goodwin said:

Which is about 2,500,00 bytes per second - a LOT of data.

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Well, it is, but since ArduCam does it, it means it's possible on principle, now I'm just looking for options...

laukejas said:

Well, it is, but since ArduCam does it, it means it's possible on principle, now I'm just looking for options...

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Then be prepared to spend money on it

Nigel Goodwin said:

Then be prepared to spend money on it

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Could you be more specific, please? As I said the ArduCam is too bulky for my robot. What (expensive) alternatives are there?

laukejas said:

Could you be more specific, please? As I said the ArduCam is too bulky for my robot. What (expensive) alternatives are there?

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I've no idea, but as it's an unusual requirement it's likely to be expensive, assuming you can even source one.

Nigel Goodwin said:

I've no idea, but as it's an unusual requirement it's likely to be expensive, assuming you can even source one.

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Which is the reason why I posted this here Hopefully someone will offer some suggestions.

The Raspberry Pi boards have a dedicated camera connector and both those and the matching camera are relatively small.
Not exactly cheap, but not crazy prices either..

eg. https://thepihut.com/products/raspberry-pi-camera-module

The Pi has plenty of CPU power for video processing and can take a suitable micro WiFi module in one of the USB sockets, so it gives you a lot of facilities in one go.

No idea if it would be physically compatible, just something to consider.

rjenkinsgb said:

The Raspberry Pi boards have a dedicated camera connector and both those and the matching camera are relatively small.
Not exactly cheap, but not crazy prices either..

eg. https://thepihut.com/products/raspberry-pi-camera-module

The Pi has plenty of CPU power for video processing and can take a suitable micro WiFi module in one of the USB sockets, so it gives you a lot of facilities in one go.

No idea if it would be physically compatible, just something to consider.

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Thank you for the suggestion, but as far as I understand from that link, this isn't SPI or I2C interface camera either? It would still require a lot of pins, correct? I want to build this robot with ESP32, not Raspberry, because of size and power consumption considerations. Is it possible to interface that camera with ESP32 without using up more than 6 pins?

laukejas said:

Is it possible to interface that camera with ESP32 without using up more than 6 pins?

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I wouldn't have thought so, it uses the CSi interface, here are the connections:

https://www.raspberrypi.org/forums/viewtopic.php?t=156098

Nigel Goodwin said:

I wouldn't have thought so, it uses the CSi interface, here are the connections:

https://www.raspberrypi.org/forums/viewtopic.php?t=156098

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Yeah, well, I guess that counts this camera out... :/ But thank you for the suggestion anyway!

laukejas said:

Yeah, well, I guess that counts this camera out... :/ But thank you for the suggestion anyway!

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At least it uses less pins than the ESP32 camera - but I suspect the ESP32 wouldn't be powerful enough anyway, the PI is a full computer, not just a micro-controller.