I recently got in my hand an old phone lcd display.
Display itself seems to be useful so I took apart it from the rest, and I begun to test its behaviour.
Display is named SHARP LM167511 and its control is made by the OKI MSM6262-01, of which I found the datasheet.
Display PCB has also two rows of buttons by its side, so the exported header by which telephone controlled it are buttons headers and OKI controller pins.
Referring on the datasheet names, pins are:
GND, VCC, V5, CS, R/W, E, A0, A1, D0~7
Based on my previous experiences, I assumed V5 to be the contrast of the device, so I connected to it a potentiometer, my hope was that changing V5 voltage I could see something, but it wasn't the case.
So I built an arduino based circuit trying changing signals on the control header. Until now I had no life signs.
I agree with everyone would say: consider it broken. but I also have a spare one which does the same.
My request is: does anybody have experience with this device, or other LCD who could give me any hint on how to proceed?
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1\$\begingroup\$ Does your Arduino code follow the initialization procedure described in the MS6262-01 datasheet? \$\endgroup\$– fm_andreasSep 15, 2013 at 8:57
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\$\begingroup\$ I read the datasheet many times. I didn't see any special procedure, So I though it have to be turned on in a way as the HD44780 needs. So I tried to access the display control as specified at pag 311. Because not all OKI pins are exported, "68/80 serie" is not there, I have to figure out in which mode it is working. However, if someone knows, or have seen a special procedure to initialize the OKI controller, I would really grateful if he want to share it with me. \$\endgroup\$– AlessandroSep 15, 2013 at 9:38
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\$\begingroup\$ Link to datasheet and a picture of the device would be useful. \$\endgroup\$– PasserbySep 15, 2013 at 18:15
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\$\begingroup\$ Here a link to the OKI MSM6262 controller: pdf.datasheetcatalog.com/datasheet/oki/MSM6262.pdf \$\endgroup\$– AlessandroSep 16, 2013 at 5:29
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\$\begingroup\$ Months are passed and I still blocked on how to do something with it. It does not react to any input on its headers. I need some hint on how to initialize the oki 6262 controller. \$\endgroup\$– AlessandroNov 22, 2013 at 20:58
3 Answers
As some of you as pointed out, at last I resolved myself the issues I had.
It wasn't that easy for me to find where my problem was, and since this question seemed not to be so popular I assumed nobody cared about the solution.
Sorry if some of you, trying to give me an hint, spent their time in the pursuit of find info for me.
Problem was mainly in the negative voltage this display needed to work.
Here a blog post I made about the argument, if somebody really care about it.
http://carminatialessandro.blogspot.it/2014/05/recently-i-got-into-my-hand-this-old.html
I want to express my gratitude to anyone trying to help me spent his/her time answering this question.
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\$\begingroup\$ @EmbeddedGuy Thank you for have spent your time for trying answer my question. I really mean it. However, please consider that at the time I wrote my blog post, it were passed 6 month without having any answer from the question. I assumed nobody cared about my problem, and so I felt no need to write the answer. Again, sorry if you waste your time for nothing. my thanks also theamk who do the same for me. \$\endgroup\$ Mar 5, 2017 at 13:55
It needs a negative voltage, as you mention on your own website...
(1) Make sure communication works at all -- the controller has BUSY OUT pins for this purpose. Write some commands and use scope to monitor E input and BUSY OUT outputs. You should see that, for example, CLEAR takes ~3mS, while Display Control takes ~20uS
(2) Enable display control and ensure you see the traffic on CP/DF/LOAD pins.
(3) Send some data and ensure that DO goes all-zero when you clear and mostly-1 when you set all bits to on.
(4) Scope voltage on COM pins to ensure the waveforms match the datasheet.
