Hi all, I'm trying to send some data through I2C from an ESP32-CAM to an Arduino based board. ESP32 is acting like a sender(slave) with the address 0x04 and Arduino is the reader (master). The code: ESP32. Based on the example "slave_sender" from GitHub - gutierrezps/ESP32_I2C_Slave: I2C slave l…

The library you're using is an obsolete workaround which won't be understood by most people here, so the easiest solution would be to install the latest core for the esp32 (ESP32 Arduino 2.0.1), which provides slave functionality for the esp32, using the basic wire.h library ( Release ESP32 Arduino 2…

You must use a logic level shifter when connecting 3.3V and 5V devices.

You declare integer values, and then place them in a single byte buffer value. Why do you do that? The size of an integer is different between the two platforms. 4 bytes on the ESP32 and 2 bytes on the Arduino, but you are sending and reading single bytes for you your values. You need to write an…

I've ordered one, but I'm not sure if that's the problem as I think SDA/SCL pins from ESP32 are 5v tolerant. Also the arduino detects the ESP32, if I run an i2c scanner it will tell that there's a device with address 0x04 connected.

[image] pabloglc: I think SDA/SCL pins from ESP32 are 5v tolerant. Can you give a source for this belief ?

[image] pabloglc: I've ordered one, but I'm not sure if that's the problem as I think SDA/SCL pins from ESP32 are 5v tolerant. ESP32's pins are NOT 5V tolerant.

[image] pabloglc: Also the arduino detects the ESP32, if I run an i2c scanner it will tell that there's a device with address 0x04 connected. You may have already damaged the ESP32 by exposing the pins to 5V. Even if it seems to work, you can't trust it now. They are cheap, so order another. …

Suggest you make self stick labels that say 3.3V Only ! and put them on all 3.3v devices. It sucks to get old :older_man: .

What is the Arduino doing that the ESP32 couldn't ?

I2C from ESP32 to Arduino

Projects General Guidance

Paul_B March 31, 2022, 9:39pm 4

Always have to say - if you have an ESP-32, why would you ever need an Arduino?

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I2C from ESP32 to Arduino

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