“In this tutorial, we are going to build a simple OTG Phone Thermometer using Digispark ATtiny85 that can connect to our mobile phone via an OTG adaptor and read the real-time temperature of anything and display it on the serial monitor.
How it works!
The Digispark ATtiny85 will connect to the phone using the DigiCDC library which allows the Digispark to appear to a mobile or computer as a Virtual Serial Port when connected by USB. This makes it appear just like a standard Arduino and allows the use of the Serial Monitor. Then we read the temperature using a Precision thermistor and we use the Serial print function to print it on the serial monitor.”