Communication using I2C between Attiny85 (Slave) and NodeMCU (Master)

[Gunner]

Try existing libraries for this type of data transfer - Arduino EasyTransfer is one I have worked with before.

Turning "Old" Arduinos into Perfectly Usable IoT Devices

Dual MCU communication with EasyTransfer And some simple, unrefined, demo code running Blynk on a ESP8266 that is sending control signals to an Arduino that is running a stepper motor. Code for ESP8266 - Running Blynk and sending control info to Arduino over Serial #include <BlynkSimpleEsp8266.h> // For Blynk #include <ESP8266WiFi.h> // For Blynk & OTA #include <ESP8266mDNS.h> // For OTA #include <WiFiUdp.h> // For OTA #include <ArduinoOTA.h> // For OTA #include <EasyTransfer.h> // …