I have ESP8266 ESP-01 module purchased on eBay.
I bought a bi-directional level shifter board ( http://i.ebayimg.com/images/g/yD8AAOSwpDdVRM9R/s-l1600.jpg ) also on eBay.
I cannot figure out why
a.) ESP8266’s RX pin <—> Arduino RX pin === works
b.) ESP8266 RX pin <—> [ LV1 level shifter board HV1 ] <—> Arduino RX pin === fail
By fail, I mean that I get no response to AT command in Serial Monitor.
I am using the Arduino Uno as a USB to serial converter. The Atmega microcontroller has been removed.
I have a separate 3.3V power supply.
I checked the voltages on the level shifter board, and they are fine.