My idea is:
PC -> arduino 1-> ESP8266 1 -> ESP8266 2 -> arduino 2 -> LEDs
If I'll programm arduino 1 to receive data from serial port and open transmission by ESP 1 to sending this data, do I have to programm arduino 2, or can I leave it just like it's now, connected to PC serial? I mean, If I'll make connection and sending data to ESP826 1, will automatically data transfered to serial on ESP8266?