SERIN confusion on receiving a string of characters.

[CuriousOne]

Tried to use this with arduino, instead of RS-232. But it does not work, since polarity is inverted.
Added simple 1 transistor inverter and everything is fine, but maybe it is possible to modify PBP settings for SERIN2 to accept "inverted" serial data?

[HenrikOlsson]

Not sure what you mean by "arduino, instead of RS-232" but if you take a look at the SERIN2 section of the manual you'll find:

Mode is used to specify the baud rate and operating parameters of the serial transfer.
The low order 13 bits select the baud rate. Bit 13 selects parity or no parity. Bit 14
selects inverted or true level. Bit-15 is not used.

and

Bit 14 selects the level of the data and flow control pins. If bit 14 = 0, the data is
received in true form for use with RS-232 drivers. If bit14 = 1, the data is received
inverted. This mode can be used to avoid installing RS232 drivers.

So if 16468 works WITH external inverter then flipping bit 14 should make it work WITHOUT external inverter.

[Ioannis]

Needless to say that everything regarding Serin and Serin2 is in the manual with detail.

Cannot see connection of the above to Arduino...

Ioannis

[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