UART to RS-485 with Auto Direction Control

It's a small board for interfacing purpose. It convert uart signal from mcu to rs-485 using a transceiver from maxim integrated. There's a pin to control the direction (switch) between sending or receiving. Unfortunately in my case, I run out of pin on my microcontroller, so the switching must not using any additional pin, hence it must be automatic, and it was actually quite easy to do the trick, utilizing the state when the Tx pin will be 0 or 1, and luckily it works, it can even transmit with speed I've tested only until 2Mbps.