[fpc-pascal] How to use UART of ARM platforms (e.g. Raspberry Pi ) through free Pascal?

[Luca Olivetti]

Al 04/07/13 12:08, En/na Dennis Poon ha escrit:
> thanks.
> I am not using the fpc email as it seems off topic.
> 
> May I know the exact brand and model number of the adapter you used?

I don't know the exact model, but it is one of these

http://vscom.de/1_1_09.htm

however there are other brands that should work equally well

> I have an ATEN usb-to-serial cable (UC-232A) but I am not sure how to
> connect its serial pins to rs-485 's DIFFERENTIAL LINES and how to set
> that adapter into half-duplex translation mode.

That's not good: you'll need a level converter (which will probably cost
more than an usb to rs485 adapter) *and* use one of the control pin to
commute between tx/rx, the problem is, when you transmit you don't know
when the last bit exits the serial port, so you cannot reliably control
the switching pin. An usb<->485 adapter usually does it all by itself at
the right time.

Bye
-- 
Luca