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temperaturemesure for_lcd_contrast

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Blubb

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I need a cheap tempsensor to
set the Contrast of a
high temperature LCD - Display
to somebody khnow one

i like to try TMP 100 from TI

i mußt mesure the Temp. from 0°C to -20°C
and set a hight voltage for Contrast

MFG
 

Maddin

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Hi blubb,

for the temp. sensor take a look at the LM75 . It's very sinple to use in conjunction with an MCU since its interface is an standard I2C one.
To change the contrast of your LCD you will require something more than just the temp-sensor, but this depends on the display you use. If it takes some analog voltage to regulate the contrast it will be a good idea to take a DA converter :wink:

regards
Maddin
 

Blubb

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Hi Maddin,

what do you mean to setting the contrast voltage
via a PWM with RC filter 4,8 K to 10 uF and a 10 Kprallel
to the Capacitor.

I like to set the values for the right ambient temperature
one time in the software.
Is this good for all oter Displays in the Produktion,
or mußt i set the contrast individual
 

Maddin

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hi blubb,

if you require an analog voltage to regulate the contrast of you display (I do not know anything about your display!), some PWM feed to an low-pass filter (RC combination) should work. You only have to ensure, when using this method, that the cut off frequecy of the filter is low enough to get a smooth analog output voltage.
I've also seen some display that require direct PWM signals to regulate the contrast of the display. Which type of signal is required must be documentated in the displays datasheet!
Hope it helped,

regards
Maddin
 

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