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hello188
Joined: 02 Jun 2010
Posts: 74
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| Driving LCD in sleep mode |
 Posted: Mon Jun 07, 2010 1:46 am |
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Hi, all
The data sheet for the PIC18F65J90 states that I can keep driving the LCD while in sleep mode using TIMER1.
To use timer1 to drive LCD, can I just feed external pulse to T13CKI pin or should I have full TIMER1 oscillator on?
Thank you |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Jun 07, 2010 11:35 am |
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| Quote: |
To use timer1 to drive LCD, can I just feed external pulse to T13CKI pin
or should I have full TIMER1 oscillator on?
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Their intention is that you should put a 32.768 KHz watch crystal on
the Timer1 oscillator pins and enable the oscillator. But, I think it
would also work the way that you propose.
Make sure you setup the LCD clock divisor correctly. They want to get
a 1 KHz output, to drive the LCD. If you use 32 KHz external input
signal, then you need to set the divisor to 32. This gives 1 KHz for the LCD.
The PIC data sheet says:
| Quote: |
The LCD clock generator uses a configurable
divide-by-32/divide-by-8192 postscaler to produce a
baseline frequency of about 1 kHz nominal, regardless
of the source selected. The clock source selection and
the postscaler configuration are determined by the
Clock Source Select bits, CS1:CS0 (LCDCON<3:2>). |
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hello188
Joined: 02 Jun 2010
Posts: 74
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| asd |
| Posted: Mon Jun 07, 2010 9:11 pm |
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| Thanks, i got it working by using 31Khz internal oscilaltor |
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