I destroyed ESP32 CAM + servo motor :'(

Hardware
1

Below was my setup (instead of an arduino, it was actually an ESP32-CAM)

CleanShot 2022-07-12 at 23.50.15@2x
CleanShot 2022-07-12 at 23.50.15@2x2616×1512 356 KB

A few seconds after... I got smoke on the servo (sg90) and burn smell on the esp32-cam. Both are dead now.

I'm fairly new to this so I'm trying to understand what happened.
I imagine the issue was the high voltage of the power supply which was too high for the servo?

  1. How was I supposed provide supply to the servo?
  2. Why did the ESP32 CAM burned? I read that providing 12V to the its 5V pin would be ok since the ESP would regulate the voltage down?

Thanks

2

Servos are usually rated for 4.8-6V, and they need a separate power supply. A 4xAA battery pack works well for 1-2 small servos. Don't forget to connect all the grounds.

Power the ESP32-CAM with a regulated power supply, either 5V or 3.3V, capable of at least 500 mA.

3

I understand, thanks.

There is a VCC 3.3V pin on the ESP32-CAM. If this pin provided 5V, would it make sense to use it to power the servo?

4

Absolutely not. Servos draw huge amounts of current, compared to MCUs, and inject very damaging voltage spikes and electrical noise into their power supplies.

That is why wise experimenters always use separate power supplies for motors, servos and solenoids.

5

I'm glad I asked, thank you for the detailed answers!

6

You will see tutorials on line that tell you it is OK to power a servo from the Arduino 5V output.

Who knows why? Sheer ignorance, or maybe they get kickbacks from people who sell replacement Arduinos and Arduino-lookalikes.

7

How come we see so many manufactured devices with only one power supply? What is their secret?

For example, the switchbot has only one battery to power the board and the motor

CleanShot 2022-07-13 at 12.20.13@2x
CleanShot 2022-07-13 at 12.20.13@2x1920×1035 117 KB

Image taken from - YouTube

8

@jremington ?

9

Are you assuming a motor and a servo are the same thing ?

You can use a low power motor and gear it down to do all sorts of stuff at low power, but that does not make it a servo.

10

In a word: EXPERTISE.

The companies that make such products hire highly trained engineers, who know how to design such circuits and make them work reliably. Typically four to six years of higher education, along with further professional experience is required.

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