NodeMCU ESP8266 to Arduino by Digital Pin

Hello Forum,

I believe I got the right sub-forum for this Question.

In my setup I am going to be using a single digital pin per Arduino for In/Out data and another pin for signalling all the other Arduinos to “flip”.

The segment in the project in question is that I am using a single Arduino to tell up to 9 arduinos to start reading from their I2c bus (which is attached to an accelerometer) via each individual cable. So the starting state of the Controller and Receivers is “Write > Read” but once the flag signal has been received, the direction of data changes for the Controller and Receiver to “Read < Write”. I then use the global control pin the signal all the Arduinos to return to waiting state (“Write > Read”). (If you want to suggest I2c for everything, please read postscript).

This currently works happily in Arduino to Arduino but the NodeMCU (although arduino under the hood) is 3.3v logic to 5v logic so I have to be careful I don’t blow the NodeMCU and am using a bidirectional 3.3->5v logic converter.

The one purchased is: https://www.amazon.co.uk/gp/product/B077WQYL6G/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Looking at the board (no associated data sheet) it has an SMD 103 resistor (10k) in line with ground (pull down) but what I want to prevent is if in the limited scenario that the two devices going into a start where both are out or both are inputs, I want to current limit to protect both systems.

In other posts I’ve seen people recommend placing a 1k/4k7 in line between the two Arduinos but for the NodeMCU should I put a 1k/4k7 between the NodeMCU and the Logic converter and another resistor between the Arduino and the Logic Converter?

The electronics knowledge in me says yes but it’s rusty and unused so thought best to ask.

Thanks in advance!

P.s. (I2c not suitable for this application as both the NodeMCU and the Arduinos are using their Buses as Masters for something else and in this case I am only doing a signal to say (Master)“turn on”, (Slave)“I’m done” and “Master reset”. I also need to do direct port manipulation as I need to be as accurate and as fast as possible which is not possible with multiplexing between units. Plus the discovery of connected sensors is far easier when just signalling.)

Tabbykatze:
but the NodeMCU (although arduino under the hood)

I am not sure what you mean "arduino under the hood".
NodeMCU module uses ESP32866 microcontroller.

ieee488:
I am not sure what you mean "arduino under the hood".
NodeMCU module uses ESP32866 microcontroller.

It uses an ESP32866 microcontroller but it can be manipulated in the same way under the hood as a standard arduino. The major difference being that one uses 3.3v logic and the other uses 5v logic.

I'm think I should have potentially put this more in the Electronics Sub-Forum, would anyone be able to help?