(reposted with tag corrected to [EE:], thanks James)

At 03:02 PM 9/3/2003 -0400, you wrote:
>At 09:31 PM 9/3/2003 +0300, you wrote:
>>Thanks to all who responded. Maybe I did not make myself clear. I have
>>hd44780 compatible lcds which are no-name no-datasheet types ;-). They
>>work ok but there is not enough contrast even if the Vee is taken to GND,
>>with nominal 5V supply. These LCDs do not allow Vee to go negative.
>
>How do you know this if there are no data sheets?
>
>Standard temperature LCD glass requires the controller 5V < Vee <= 0V.
>Extended temperature types do require more like 0 >= Vee >= -5V.
>
>I suggest adding a 7660 and a couple of capacitors..
>
>Best regards,
>
>Spehro Pefhany --"it's the network..."            "The Journey is the reward"
>speff@interlog.com             Info for manufacturers: http://www.trexon.com
>Embedded software/hardware/analog  Info for designers:  http://www.speff.com
>
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Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

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