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Topic: LCD shield and/or LCD serial backpack (Read 34 times) previous topic - next topic

Cheater

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Presumably you will be using the RW line rather than delays to determine when the LCD is ready to accept data.

Yep. Its got a dedicated chip so there is no need to cut corners with the pins. :)

Also I just realised that I can make the backlight brightness variable.

VenPixel

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Quote
Presumably you will be using the RW line rather than delays to determine when the LCD is ready to accept data.

Yep. Its got a dedicated chip so there is no need to cut corners with the pins. :)

Also I just realised that I can make the backlight brightness variable.


Not sure if you have taken a look at Peter Anderson's K107 backpack. Should at least provide a good reference for designing your own backpack..
Ven Pixel
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Wandering Samurai
"Since light travels faster than sound, p

Cheater

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If you do want to put the Arduino bootloader on it, you should probably do a lot of testing to make sure it doesn't cause any problems.

Sorry I missed your post.

If they are using it with a Arduino then it wouldnt matter at all because they would have to wait anyway.
Ladyada has a hack which starts the program if anything other than 00 is sent to the bootloader so that would also work.
I might put a SMD jumper on to enable/disable it. Just solder over it to enable.

The K107 looks good but it has a awful number of limitations.
I can steal some ideas from its software though. :)

Cheater

Ok I've finished fiddling with it. Here is the design so far:



I ditched the ICSP connector to save space.
Since I'm breaking out SPI anyway, it'll be simple to make a adaptor.
The labels need to be moved around a bit as well.

It should be breadboard compatible and you'd be able to use a DIP-16 socket if you wanted.
You can also solder it directly to a LCD or even put a socket on it so its removable.

Any feedback?

Also what kind of transistor should I use?
It controls the backlight so it needs to handle about 200mA.

mem

Looking good!

More a passing thought then a suggestion, but I was wondering if you would gain real estate and lower cost replacing the contrast pot with a  transistor and capacitor  driven from a spare onboard pwm pin.  Providing the arduino with software commands to increase and decrease contrast may be more convenient then getting at the pot.

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