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Can not get CFAG14432B-TFH-T#T to work at all :(

raddybaby

New member
Hi All,

I purchased both a CFAG14432B-TMI-T#T and a CFAG14432B-TFH-T#T display and I initially tried to get them to work in graphic mode...I gave up on that (I made no progress :() and have no tried unsuccessfully to get it to work in character mode.

My code is based on the code found here: https://forum.crystalfontz.com/showthread.php?t=5758&highlight=CFAG14432B (thanks for posting!) FYI I do not use a mask on the Flagdata and noted the other comments made.

I have checked and double checked the wiring...and tried both displays :(

I have also used my ICD3 debugger to step thru the code to make sure all voltages are correct (based on my code) during the initialization process

VDD : I am powering the display with +3V ...the display data sheets says +5V but the controller datasheet say 2.7V minimum so I believe this is OK

V0 : I have have a 10K pot between +5V and gnd - there seems to be very little difference between gnd & +5V for contrast...I find this a bit strange???? You can just make out the 144x32 matrix of "dots"

After initialization I load the controller with some text "testing!!!!!" - this reads back correctly and the AC increments as expected.

As i am able to read back the info from the display I am wondering if it could be i need a VDD of more then 3V for the display...or perhaps i don't understand the Vo requirements for the contrast adjustment (perhaps the display is working but the contrast is out of whack????)

Does anybody have any ideas???

Please help...this is driving me crazy!!!!!! ;-)

Thanks and cheers,
Neal
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As i am able to read back the info from the display I am wondering if it could be i need a VDD of more then 3V for the display...or perhaps i don't understand the Vo requirements for the contrast adjustment (perhaps the display is working but the contrast is out of whack????)
The data sheet shows that the LCD requires 4.2 to 5.5 volts for contrast, dependent on temperature. So, with a 3 volt Vdd, you would need -1.2 to -2.5 volts on Vo to adjust contrast. Thats why the recommended Vdd is 5 volts, so you won't need a negative voltage to get enough contrast.
 
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