QY–162A LCD module in 4 bits mode - how to troubleshoot?

vaclav_sal

I have BS2 hooked up to QY-162A LCD module and cannot make it work in 4 bits mode.
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The Hitachi doc says that it comes up in 8-bit mode on power up and needs to be set (initialized) to 4-bit mode in several attempts using single (nibble) output if the control data variable is a byte.
To output characters it says that you need to output the high nibble first and than the low and than read the busy flag (four times).
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I have not found a working BS2 sample code (4 bits interface) anywhere.
Some of the samples even state not to worry about the busy flag and are using PAUSE liberally!
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My basic question is – do I need to send both high and low nibbles even when only one is required to set a· “function” and than send four (enable) pulses to satisfy the busy flag?
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Right now I do not know if I have hardware or software problem.
There is no feedback from any of the initialization steps described by Hitachi.
So, how do I troubleshoot this?
Any constructive help is appreciated.
Vaclav

Chris Savage

Hello,

If your display is truly Hitachi compatible then the code examples on the following page should help. Take care.

CLICK HERE

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Chris Savage
Parallax Engineering

MrBi11

here is some info on the HD44780 that it is suppose to be a clone of:
home.iae.nl/users/pouweha/lcd/lcd.shtml



[noparse][[/noparse]I couldn't find to much on QY-162A]