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HD44100H LCD

moeburn

Jun 25, 2012
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Hello! I just found that Active Surplus was selling these little 16x2 LCDs for $1!

It's a very simple circuit board, LCD on the front, as well as two button contacts labelled "clear" and "secure". On the back, there is a single HD44100H driver, and a 10 pin ribbon connector leading from the driver. I bought one, because a quick google search on my phone at the time lead me to believe that the HD44100H was similar in operation to the HD44780, which is widely supported by almost every LCD-controlling software on Windows.

Now how would I get this working on my PC? I assume I would need to build some sort of USB to RS232 converter, I have a very simple circuit I have built before for that, so that's no trouble. But does anyone have any idea which pins do what?
 

davenn

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Sep 5, 2009
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you would have to google for a datasheet or go to the manufacturer
those would be the first 2 initial choices :)

Dave
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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25,510
There is a circuit that uses a 74HC595 to control an LCD with essentially a single pin.

This circuit requires some fairly exact timing on the signals, but it it almost within the bounds of possibility that you could bit-bang something from an RS232 interface to drive it.

It may be far simpler to use something like an Arduino Nano as it has the USB interface and plenty of pins to drive the display (and also lots of software to drive standard LCD panels).

But as Dave suggests, you also need to get the datasheets (or perhaps experiment) to make sure they really are compatible with the 44780.
 

moeburn

Jun 25, 2012
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And then there's this:

pwb502401.jpg


This is just a 4-digit display! I have no use for that. But it looked EXACTLY like a 16x2 character display! Oh well, it was only a dollar, no biggie.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Oh well...

What's that you're driving it with?
 

moeburn

Jun 25, 2012
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Oh well...

What's that you're driving it with?

Thats not me, thats the spanish blog I linked to. Looks like some mini Arduino version, or could be the guy homebrewed a microcontroller setup, I don't know
 
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