I have to arduino's which are communicate using rx/tx. Arduino1 (A1) send data over serial to Arduino2 (A2). My questions are:
1 - If A1 do Serial.print each 50ms and A2 reading serial each 100ms which value will get A2? For example A1 send "1" and after 50ms send "2". Considering A2 will read serial after 100+ ms it will get "2" ?
2 - If A1 send data each 100+ms and A2 read at 50ms which value will get A2 between? For example A1 send "1" and A2 read "1" when read at 50ms but when it read again after 50ms (during that time A1 didn t sent anything ) will read again "1" ?
Thank you
1 Answer 1
1 - If A1 do Serial.print each 50ms and A2 reading serial each 100ms which value will get A2? For example A1 send "1" and after 50ms send "2". Considering A2 will read serial after 100+ ms it will get "2" ?
The Arduino has a 64 byte (software) buffer. You will get the numbers in sequence up until that buffer overflows. Then it's not easy to predict what the results will be.
Probably something like:
121212121[...]2121212121212111111111111111
2 - If A1 send data each 100+ms and A2 read at 50ms which value will get A2 between? For example A1 send "1" and A2 read "1" when read at 50ms but when it read again after 50ms (during that time A1 didn t sent anything ) will read again "1" ?
If there is nothing in the buffer the read function returns -1. That can be mapped (IIRC) into ASCII (depending on your software) as ÿ so you would get:
1ÿ1ÿ1ÿ1ÿ1ÿ...
You should read my tutorial on reading serial on the Arduino.