What is max sure tested baudrate for SoftwareSerial library on UNO/MEGA ?
Many thank
I suggest starting at 9600 baud and then trying higher speeds. i believe it will work at 38,400 baud.
...R
I flashed firmware to esp8266 with sketch copying bytes from Serial to SoftwareSerial at 38400 baud, but when the same sketch copied bytes of prints from the esp8266 to Serial, garbage occurred. TX works better then RX
70K is achievable especially for sending. See tests here - SoftwareSerial magic numbers - Libraries - Arduino Forum
TX is more robust than RX but both are sensitive for the amount of interrupts.
Software Serial RX should be rewritten with pinchange interrupts to be more reliable...
nice student project 
realmeteo:
What is max sure tested baudrate for SoftwareSerial library on UNO/MEGA ?
Do you really need to ask this question for a Mega?
Software Serial RX should be rewritten with pinchange interrupts to be more reliable...
nice student project
Umm... I think you are talking about NeoSWSerial. 
I fixed a few other problems, like allowing simultaneous RX and TX.
AltSoftSerial is even better.
And, like Nick_Pyner is suggesting, you should never use these software serial libraries on a Mega. Just use the hardware serial ports Serial1 (pins 18 & 19), Serial2 (pins 16 & 17) or Serial3 (pins 14 & 15).
Nick_Pyner:
Do you really need to ask this question for a Mega?
cut and paste error....
obviously no !
tnk