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Newbie and CFAG12864A

Enable is the clocking signal for writing and reading. Normally E is low when nothing is accessing the display.

To write data or command, put the data byte on the port pins, then take E from low to high, and keep it high for 500 nS or longer. Then take E low again. The data is clocked into the display on the falling edge of E. Do not do another write until 1 uS has elapsed. That means you may have to use a delay while the E is high, and again after it goes low, to meet the timing minimums.

Do you need the explanation for reading?

This info is on pg 9 of the data sheet, and you are good at reading data sheets, right?
Has this oscillation always occurred, or did it just start recently?

What is the measurement of Vdd (pin 2)? Is it steady?

If you disconnect the negative supply (pin 18) from Vo (pin 3), does the oscillation stop?

What is the value of the pot or resistors that you are using from Vout to Vdd and Vo?


New member
I dont think the oscillation happened before.

Pin 2 is at DC constant 5.28 V ( steady )

Once i disconnect the Vneg from V0 ( pin 3) , there is less oscillation ( but there is still wierd oscillation )

I think it s 10k Pot. ( Second check its 10k Pot )
Seems like there is a problem in the negative voltage genertor circuit on the display. You should send an email to CFA support (see the "contact us" link at the top of the page), and maybe they can arrange for a warranty replacement. In the email, put a link to this thread, so they can see what has happened so far.