I am currently using an Arduino Uno as a USB-serial converter; the Atmega microcontroller has been removed per tutorial http://rancidbacon.com/files/kiwicon8/ESP8266_WiFi_Module_Quick_Start_Guide_v_1.0.4.pdf
I have a separate 3.3V power supply.
I have found that if I use the level converter board for the RX pin, then I get no communication. Yet if I connect the RX pin on the ESP-01 directly to the Arduino RX pin, then I get communication.
The TX pin works fine with the level converter board.
Can anyone tell me why this is happening?