The trinket pro will acts as a bridge between the uart connection from the end of the DB9 to the ESP8266. It also parses data coming from the ESP8266 and send it to the serial console port over UART. The ESP8266 uses wifi from my phone acting as a hotspot so that the SSID and credentials never need to be changed. I connect to the ESP8266 using ncat on my laptop.
The first thing I wanted to do was to make sure that I could interface the Trinket Pro with the serial console port of a router. To do this I used a Cisco 1841, an RJ45-to-DB9 adapter, and a DB9 to USB male adapter on the end. To interface with the Atmega328 UART port I had to first break out the USB pins.
For this I used a knock-off Apple Lightning to USB adapter. I had ordered the adapter for work, but because it was a cheap clone it didn't meet the power requirements of the iPad Air I was using it with. So I cut off the lightning connector to get to the 4 USB wires. I soldered them to a common perfboard and then some male headers to that.
Next I plan on writing a simple program to basically turn the serial monitor in the Arduino IDE into a terminal for the 1841.