From: Moritz von Buttlar (info_at_baltic-microsolutions.de)
Date: 2001-12-13 06:56:01
Hi Doug !
>Are you sure that powering either from the PC serial port
>is safe? It sounds kind of strange considering that we are
>trying to isolate the EEG from the PC. What happens if
>there is a problem with the PC handshake lines?
It will be like this:
PC ---> Handshake line powered PCB --> optoisolation ---> battery powered
part of EEG
The 'handshake line powered PCB' consists of level shifters to shift
the output of the optocouplers to RS232 levels.
>I use DS275 level converters these days. They are small
>8-pin DIPs and require no external capacitors.
Sounds good. I'll check them out.
> >> Is the irDa idea better or is it really overkill?
> > It would allow our device to pass medical norms and it's
> > not much more expensive then RS232 with MAX232.
>
>But it does require and irDA transceiver on the PC.
>So many option/issues ... the question is ... who decides?
>Who is the Linus of OpenEEG? Ultimately somebody has to
>make decisions one way or another ...
I think it's not so important. Let's make the first devices with RS232 and
optocouplers.
Later when can always exchange the digital board with an IrDA
version. But sure, some decisions have to be made all the time...
Moritz
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Moritz von Buttlar
Flash uC/DSP Development http://www.baltic-microsolutions.de
Free EEG Design http://openeeg.sf.net
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