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Topic: USB Universal LCD backpack Free PCB (Read 4143 times) previous topic - next topic

USB Universal LCD backpack Free PCB

Hey Guys,

I soldered up this prototype, but have not tested it yet.  I was planning to write all the code from scratch after the USB stack was properly released (which it is now!).

There are broken out analog pins, so this would make for a cool temperature display with USB connectivity.  I don't know, it's a good little dev board (I opted for the PIC18F25J50) with LCD and USB built in.




Cheers,

MM

Re: USB Universal LCD backpack Free PCB

Reply #1
Nice work. Let me know when you start the firmware, I am here to help.
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Re: USB Universal LCD backpack Free PCB

Reply #2
Got it working last night.  I didn't have flux when I soldered that chip in, and lots of the connections were not well made.  A quick reflow fixed that, and I had it programming nicely.

I wrote myself an HD44780 LCD driver years ago, and I still use it to this day.  I quickly added that to the micro to try a simple 'Hello, world!".  Unfortunately no dice.  I checked all the connections, and they seem fine.  This leaves the elephant; I'm using a 3.3v micro and a 5v LCD!  I tried another LCD which I am sure I've used with the 5V micro before, and I get the same result.  I think my memory of using an LCD with a 3.3v micro might be flawed.

However, I designed a serial LCD backpack for a friend's business.  I still have that nicely broken out and ready to connect to the bus pirate.  I'll try running the micro on 3.3v, and see if it still works...

[Edit] So it looks like the panels need a 5v signal to drive the data bus...  In order to use this, I'll have to find a 3.3v LCD somewhere.  eBay time!

Re: USB Universal LCD backpack Free PCB

Reply #3
I did find a cheap ($6) 3.3volt LCD supply on ebay. I think the seller was "ego china".
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Re: USB Universal LCD backpack Free PCB

Reply #4
Yeah, I found a 5USD one just after posting that message :-).  Should take a month to arrive..!

Re: USB Universal LCD backpack Free PCB

Reply #5
[quote author="ian"]I did find a cheap ($6) 3.3volt LCD supply on ebay. I think the seller was "ego china".[/quote]

Can you give me plz a link to ebay I cannot find ))
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Re: USB Universal LCD backpack Free PCB

Reply #6
[quote author="viktorz"][quote author="ian"]I did find a cheap ($6) 3.3volt LCD supply on ebay. I think the seller was "ego china".[/quote]

Can you give me plz a link to ebay I cannot find ))[/quote]

Look for 1.8" tft. Actually a lot people are selling these, and egochina is one of them.

Re: USB Universal LCD backpack Free PCB

Reply #7
A chineese company that has 3.3v character lcds on their web site is http://www.satistronics.com/
I have never ordered from them.