From: Joerg Hansmann (jhansmann_at_g...)
Date: 2000-12-30 21:18:19
Hi,
----- Original Message -----
From: <yaniv_vi_at_yahoo.com>
To: <buildcheapeeg_at_egroups.com>
Sent: Saturday, December 23, 2000 12:43 PM
Subject: [buildcheapeeg] Re: to jeorg - about the infrared com ?
...
> > It is a friendly warning by SHARP , that they intend to
> > discontinue the production of this device.
>
> i'm assuming two things :
> 1.the are first version well be sold like maximum 1000 units ,
> before a better version will come .
> 2. how hard is to find a replacement for a optic led ( at least in
> theory ) ?
No Problem.
...
> my opinion is this - let's first design a first version that works.
> without need for flshing lights. (what's the need for changing sample
> freq - and is it critical for the first version ?)
> and we also don't have to implement the 1st version with code inside
> atmel processor - but instead use another one pic processor (just
> copy the irx ) .
> you seem to disagree with me about the need for simple version first,
> but you like the first version to be very very good or at least
> very good , am i right ?
The first version should be sufficiently safe (isolation), good (noise)
and versatile (as a platform for my further projects like optical
REM-Sensors for a lucid dreaming machine).
> maybe we (all the group ) should just decide what level is enough for
> 1st version ?
The problem is, that I am not very motivated to invest my time and
money in developing a device that I simply can not use for my follow up
projects.
I will need more than 5 m data line around a corner and full-duplex
communication over hardware UART at 115200 baud.
IRDA simply does not fit these criterions.
...
> > Putting medical devices on the market without licence
> > could result in high fines or up to one year in jail.
> > (And that is something I am definitely _not_
> > interested in ;-) )
> 1st - your not going to do anything against the law .
Yes. As long as I do not produce and sell the device.
> as i recall our group's purpose is just to design such a device .
> and a third side company will sell it to the public .
> so you can't be liable for anything -because you just
> design and publish the data - with non liabilty warning - to the 3rd
> side company .that's my feeling about it .
> but it doesn't says we won't do anything in our power to make
> this design very safe - and very good .
...
[optocouplers vs. IRDA]
> > > maybe it's depends on breakdown voltage of the optocouplers ?
> >
> > The manufacturer of the optocoupler must guarantee the fitnes of
> his product
> > for medical applications.
> > All datasheets I have seen have a disclaimer for medical fitnes at
> the at
> > the end.
> > An other thing is pcb design and casing. The best optocoupler
> > will not have much use, if the pcb - design is bad or it is badly
> > manufactured. Also casing could corrupt isolation.
> forget optocoupler - well use irda .
No. See my reasons above.
...
> > One proposal was to put 1 meg resistors in series with each eeg-
> input.
> > However I assume that this will increase noise.
> could you plase send me the relevant section of the design in jpg ,
It is in the file attachment.
The upper section of the schematic shows the design as it is _now_.
The lower section is the new design of the amplifier inputs. I hope
there is no need for additional 1 meg resistors.
The new design is essentially the same as the PSPICE-schematic
I have posted here some months ago. In simulation it shows
superior properties compared to the old design.
If you have questions how it works, ask.
> and tell me what youn think ,and maybe i could help you finding some
> solution , or at least just know what's it about more detailed ?
Regards,
Joerg
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