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RE: read 5V signal on parport0
To further clarify Magnus' answer: The parallel port signals on the
ETRAX 100LX are 5 V-tolerant. It is therefore safe to apply 5 V signals
on them. On top of that, the par port inputs are protected with 4.7 kOhm
resistors on the dev. board.
On Mon, 27 Oct 2003, Magnus Mårtensson wrote:
> We have connected 5V logic to par0 in the past so it is safe. You can connect the
> the 5V output from the LCD to ack_, busy_ paper_error for instance. As you can se in the schematics
> there is 4k7 ohm between the inputs and ETRAX.
> > -----Original Message-----
> > From: Henrik Jönsson [mailto:email@example.com]
> > Sent: den 24 oktober 2003 18:39
> > To: dev-etrax
> > Subject: read 5V signal on parport0
> > Hey ya
> > We have connected a LCD with a T6963C-controller to par0 (devboard 82,
> > 2.4.20) and we are writing a driver for this LCD. Is it safe
> > to read the
> > busyflags of the LCD? I mean the parport is 3.3V and the
> > display outputs
> > 5V. Is there any risk of breaking something?
> > Regards Henke