SERIN confusion on receiving a string of characters.

[CuriousOne]

The polarity of input signal. Not the byte or bit inversion, but voltage inversion.

like discussed here: https://forum.arduino.cc/t/software-...class/535584/6

[Ioannis]

Both are related. The RS232 protocol says that the line stays inactive at -12volt and the TTL output is at 5V at the same time. This forces you to have the appropriate inverter driver chip like MAX232 for example.

If you do not want to use that chip then you have to make your TTL output stay at 0Volts to fool RS232 line and if you are lucky (as is the case most of the times) the other end of the RS232 line will understand that TTL output is idling.

Hope this makes sense now.

Ioannis

[CuriousOne]

I know about hardware level converters.
I'm asking another question. Whenever is it possible for SERIN to treat input 0 as 1 and vice versa?

[Ioannis]

When you flip bit 14 as Henrik clearly stated at #12

Ioannis

[CuriousOne]

Yes sorry, just noticed that post
forum is glitching too much recent days...

[CuriousOne]

Tried changing that bit, the result is 18516.
Now it does not work at all....

[Ioannis]

Define speed, parity, polarity.

Ioannis

[tumbleweed]

Tried changing that bit, the result is 18516.
Now it does not work at all....

Not sure what you "flipped", but 18516 = $4854

You had 16468 = $4054.

bit 14 = 16384 = $4000, so flipping bit 14 should give you
$4054 - $4000 = $0054, which is 84 dec