Need help for the connections and coding of AI Thinker ESP32 Cam, Level Shifter, and Arduino Mega 2560

Projects General Guidance
1

Hello everyone! I need urgent help.

I am a student and working on a project that involves AI Thinker ESP32 Camera, Level Shifter and Arduino Mega 2560 in which detects various fire hazards. My problem is the serial communication between the Arduino Mega and ESP32 Camera. When I upload the code, a message will prompt that says:

"Failed to connect to ESP32: No serial data received."

In my own opinion, this problem involves the code and the connection. Here are the connections:
ESP32 Cam 3V3 - Level Shifter LV
Level Shifter HV - Arduino Mega 5V
ESP32 Cam GND - Level Shifter GND
Level Shifter GND - Arduino Mega GND
ESP32 Cam RX - Level Shifter LV2
Level Shifter HV2 - Arduino Mega TX1
ESP32 Cam TX - Level Shifter LV1
Level Shifter HV1 - Arduino Mega RX1

2

And you did verify all the connections with your DVM, digital multi-meter?

3

(post deleted by author)

4

Unfortunately, I don't have DVM. Any idea on verifying the connections.

5

Then buy a DVM, they are about £10 from a thrift shop.

Or make your own continuity detector from a couple of coin cells a led and resistor. Make sure to only use it on unpowered up circuits.

6

Since we can't see your code or wires, it is difficult to say, but my hunch is that it is either wired incorrectly or the code is wrong.

I don't see a 3V3 supply or a 5V supply.

I do see you using board pins acting as the level shifter supply voltages. That is generally a bad idea.

A single 5V supply can power both boards and the Level Shifter HV. I would then use a buck converter to tap off a 3.3V supply for the LV. A standard 5v cell phone charger of 1A should work but a 2A would be safer.