using nodeMCU ESP8266 with Arduino Mega

hi guys i need help. so im working on a project and i was first using nodeMCU because of the wifi and now that im like 50% done with my project i realized that the nodeMCU has a limited GPIOs and i need more to make my project work. so now im thinking maybe it is possible to use this with my Arduino mega. is it possible to use the arduino mega to communicate with my nodeMCU? i have already created an html for my nodeMCU and it is already working how can i use this with the arduino mega? cause i need to send datas from the webserver like floats and integers. thanks.

hi guys i need help. so im working on a project and i was first using nodeMCU because of the wifi and now that im like 50% done with my project i realized that the nodeMCU has a limited GPIOs and i need more to make my project work. so now im thinking maybe it is possible to use this with my Arduino mega. is it possible to use the arduino mega to communicate with my nodeMCU? i have already created an html for my nodeMCU and it is already working how can i use this with the arduino mega? cause i need to send datas from the webserver like floats and integers. thanks.

Do you intend to program the nodeMCU as the web server, etc and establish a communications link between it and the Mega for transferring data? Or, will you be doing everything on the Mega and controlling the nodeMCU as a WiFi modem via AT commands?

Hello Brownoutee!

Interesting question!

AS far as the communication between the ESP 8266 and Arduino MEGA is concerned obviously, you can let them communicate using any standard peripherals.

Coming to limited GPIOs, you can use any GPIO expander in order to cater this issue. Also note that you can employ Arduino UNO as GPIO expander.

I hope this would solve your problem!!

I want to use the nodeMCU. the mega for turning on relays, pwm driver, and getting values from some LDR.

OKay!

Then you can use the MEGA as the IO expander. In this way you can exploit all the functionalities of the Arduino MEGA.

brownoutee:
I want to use the nodeMCU.

That didn't answer the question. You want to use the nodeMCU how?

i want to use the nodeMCU for the programing cause i already made a webserver for it. and i want to use the mega like an extender so that i can have more GPIOs

OK, then you'll need a communications protocol between the nodeMCU and the Mega. Something over Serial would probably be easiest. The Mega has multiple hardware serial ports, so don't bother with SoftwareSerial. You must be cognizant of the supply voltage difference. I don't don't if the Serial pins on the nodeMCU are 5V tolerant, I've only ever interfaced ESP8266 boards with other 3.3V boards. You'll need to find out.

There are are number of serial transfer libraries out there. I've haven't used any as I typically roll my own. Others may chime in on that.

Google 'Arduino GPIO expansion' .

No need for an Arduino Mega.

is it possible to make the mega operate in 3.3v?

I’ve merged your other cross-post @brownoutee.

Cross-posting is against the rules of the forum. The reason is that duplicate posts can waste the time of the people trying to help. Someone might spend 15 minutes (or more) writing a detailed answer on this topic, without knowing that someone else already did the same in the other topic.

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