I have WiFi ESP8266 module:
I connect VCC to 3.3V, CH_EN to 3.3V, GND, Rx (module 7 pin) to ATmega16 TxD PD1, Tx (module 2 pin) to ATmega16 RxD PD0.
After I send by USART "AT" command I expect end up in ISR (USART_RXC_vect)... but nothing happend.
Did I make correct module connection?