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

[Luca Olivetti]

Al 04/07/13 11:16, En/na Dennis Poon ha escrit:

>> With RS-485 hardware you can - and supposedly need to - do
>> "half-duplex with output enable", if your hardware provides this.
>>
> After days of google search, I am afraid the bcm2835, the Soc of
> Raspberry Pi (the hardware I have to use) does not provide this hardware
> support :-(
> It states that it does not even support interrupt. Polling is the only
> way for events :-(

If that's true, you could use an usb to rs485 adapter, most of those do
the tx/rx switching automatically, so you just see a "normal" serial
port (of course you'll have to manage the high level protocol yourself).
I've mostly used them in 422 mode (4 wires/full duplex) but I used one
of them once in rs485 mode (2 wires/half duplex).
IIRC the brand was VSCom.

Bye
-- 
Luca