I'm looking for some help surrounding a very small project I have been looking to do. Basically I have a requirement to read the output from a serial port (currently an RJ45 connector) and check the output. Based on the output, I then need to trigger a Wifi sensor which will be handled outside of this project on a web interface/android app of my creation at a later date.
The serial output will be a series of fullstops repeating (......) and upon this series of fullstops no longer being the output from the serial port, I need the Wifi sensor to be triggered. The Wifi sensor is an ESP8266 and I'm looking to make this as small as possible (ATTiny45 or smaller?)
Can anyone help me construct a prototype through an arduino or directly onto the tiny45 that allows this to happen. I can either take power from an external battery pack or possibly from the serial port itself if such power even exists...
If anyone needs more information, please feel free to ask.