Update README.md

README.md

 # ktnn-wifi-30a
 
-Custom firmware for KTNNKG wifi 30A module
\ No newline at end of file
+Simple custom firmware for KTNNKG wifi 30A module. 
+
+Connects as client to the provided wifi hotspot (must be IEEE802.11 b/g/n (2.4MHz)) with a hardcoded ip address.
+
+## hardware setup
+
+* WIFI module is marked as PSF-B01
+* The pinout matches with [this one](https://www.itead.cc/wiki/PSF-B85). **Note the bottom view.**
+* **Soldering is required**
+* Programming cable - [this one](https://www.amazon.com/gp/product/B07784SHF7/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) with 3.3V used for VCC
+
+## build and upload
+Arduino 1.8.9:
+* Board: **Generic ESP8285 Module**
+* Upload speed: **921600**
+* CPU frequency: **80 MHz**
+* Crystal frequency: **26 MHz**
+* Flash size: **1M (No SPIFFs)**
+* Reset method: **ck**
+
+Short GPIO0 to GND and power on to boot in the programming mode.
+
+Upload the sketch. Check the serial output.
+
+Power off, disconnect the programming cable, connect input wires, power on.
+
+http://ip/on
+
+http://ip/off