Using arduino Uno to code ESP32-CAM module

Using Arduino Project Guidance
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emergency
(sorry, I'm in a hurry about making this project because I have to attend a competition)

Hello, I am a starter for arduino.
I want to connect an arduino UNO to an esp32-CAM so that I can program both of them.
My final goal is similar to: when something is triggered in arduino, the esp32 camera will capture a photo and send some data to arduino.

I have read some other tutorials and texts and some of them say that I need a FTDI adapter when sending the code to the esp32-camera. Some say that I need a logic level converter because the voltage of esp32 and arduino is different.

I want to know if I can do without the FTDI and logic level converter?
If I must, how is the wiring of it?

Thanks in advance. I would appreciate if anyone could answer my question.

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Programming The ESP32 Cam Using Arduino UNO

How to Program / Upload Code to ESP32-CAM AI-Thinker (Arduino IDE) | Random Nerd Tutorials

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If you get these esp32-cam modules you can use USB to program.
https://amz.cx/3Bi6

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thank you for your links.
however, I think esp32 use 3.3V, while arduino supply 5V.
If I just build the circuit according to the first link, will the esp32 burn out?
Can I simply use a resistor to lower the voltage?

Also, second question: if I want to send data from esp32 to arduino, is the circuit the same?

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A voltage divider from the Uno Tx to the CAM, the yellow wire here --

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I suppose that's a good idea. I had read recently a discussion of programming via a Uno. I haven't seen any done 'with' a voltage divider, but it seems prudent.
You asked a question about "How?" and I provided two examples.

IMO, the USB-to-Serial, if it's one that's 3v/5v switchable, may be the 'better' choice.
If you only have a Uno, that's not a bad or inferior way to do it.

Here's the topic with the discussion mentioned previously --
Upload to ESP32-CAM using UNO fails: "No serial data received" - Using Arduino / Avrdude, stk500, Bootloader issues - Arduino Forum
Lamentably - nobody provided a wiring diagram of any sort.

2 Likes
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Thanks for your information!
That means, you should connect the RX of arduino and RX of esp32 together, instead of RX to TX?
Also, do we need to handle the voltage of the green line with a voltage divider?
If I am sending other data (like when a button has been pressed) from the arduino to the esp32 camera, should I also connect them according to the diagram you drew?

Thank you so much

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To do this - yes.

The signaling/data from the CAM is 3V, no purpose in trimming that down.

The diagram shows the programming configuration only.

If you are going to have comms between the Uno and the CAM, operationally, then that would have to be TX of one to RX of the other.

1 Like
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sorry for bothering you for such a long time.
But I want to confirm, when sending the code the esp32, this should be the wiring, right? (left: esp32 cam, right: arduino)

5V - 5V
GND- GND
GPIO 0- GND
UOR - RX
UOT - TX
GND(arduino) to RESET(arduino)

And after sending the code, change the two wire to
UOR - TX
UOT - RX

but do I have to turn off the power of esp32 cam and arduino before changing the wire?

Thank for your help so much

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What wire?
With everything off, configure the wires, then program it.
Turn everything off, remove the wires, go on with life.

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I believe that @caspar9872 means that after the ESP is programmed and caspar now wants to establish serial communications between the Uno and ESP what need to be done

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yeah that's what I mean

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You need to continue using the voltage divider.

Have you done anything yet?

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not yet, I'm still purchasing the esp32 cam
Anyways, thank you so much for your help!

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And I thought this was an emergency

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hmm...
it's kind of emergency because it is urgent to buy the stuffs
Sorry for misleading