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Inexpensive sources for electronic parts...

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mbu

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Just curious...

Today I noticed that Wal-Mart has a calculator that can be had for $1.00 USD. I'm looking for a numerical LCD display and, for that price; there is no way I could get one thru the electronics supply houses. Is it possible to use items like this for parts or is finding data sheets, etc. on items obtained this way impossible thereby making it foolish to use for hobby projects?
 
The displays in such devices are usually unable to be used in a project, although for $1 you could afford to take one to pieces and look - personally though I wouldn't bother trying.
 
A really nice LCD display that would be easily interfacable will usually cost about $10 and up (that is off the top of my head...)

Check www.jameco.com <- i use them all the time ;)
 
Those things are tailored for the specific use, and manufactured over 10000 PCS at a time, thus reducing cost to a minimum extent.

Usually such digital LCD's are just glass panels, those pins are AC driven, so you will need LCD drivers with AC output to drive the thing. And you don't wanna do this coz the wave form is kinda complicated for a microcontroller to generate. Someone here in China had achieved this with 74LS595's, but it had consumed a lot of space, and no one would be interested in implementing such architectures on end user applications.

For what price can you get a 1602 LCD with HD44780(driver&controller) and backlight?
 
Alex_rcpilot said:
For what price can you get a 1602 LCD with HD44780(driver&controller) and backlight?
A 24 x 2 is only $3.95 at the BG Micro link I posted above. Surplus lcd's I've seen nearly always come with controllers like the 44780 or other std... It's the oem units like the calculators that are problematic...
 
hmm, I think 4 bucks for a 24X2 is reasonably cheap. The price for a 16X2 LCD as I described above is sold for 18RMB(some $2.3) in China. Yup, ASCII embeded surplus LCD's usually come with std driver&controllers. I do come across some OEM panels from time to time. But I'm not saving a few bucks at the cost of integration.

Things are a little less complicated in U.S, since your language is based on the alphabet. LCD's with ASCII controllers are all you guys need. Whild in here we have a big problem to deal with. There're over 30 thousand Chinese characters, 9 thousand of which are frequently used. So besides those LCD's with ASCII code, a bunch of displays with Chinese characters can also be found in the market. The price is relatively higher, usually over $7. I've personally used a few types for $7.5, $10 and $33. Most of them are 128*64 with 16*16 character size. The $33 one has a more advanced controller made in Taiwan, which can resize the font. Really neat stuff.

Anyway, dot matrix binary libraries are open for download online and we can save such libs in memory chips. There's a simple algorithm to locate a character in this lib and fetch 32 bytes from the address to draw dots on the LCD. I've done such things with a graphical 128*64 COG LCD with 256KByte SPI memory. It was very interesting.
 
Alex_rcpilot said:
hmm, I think 4 bucks for a 24X2 is reasonably cheap. The price for a 16X2 LCD as I described above is sold for 18RMB(some $2.3) in China. Yup, ASCII embeded surplus LCD's usually come with std driver&controllers. I do come across some OEM panels from time to time. But I'm not saving a few bucks at the cost of integration.

Things are a little less complicated in U.S, since your language is based on the alphabet. LCD's with ASCII controllers are all you guys need. Whild in here we have a big problem to deal with. There're over 30 thousand Chinese characters, 9 thousand of which are frequently used. So besides those LCD's with ASCII code, a bunch of displays with Chinese characters can also be found in the market. The price is relatively higher, usually over $7. I've personally used a few types for $7.5, $10 and $33. Most of them are 128*64 with 16*16 character size. The $33 one has a more advanced controller made in Taiwan, which can resize the font. Really neat stuff.

Anyway, dot matrix binary libraries are open for download online and we can save such libs in memory chips. There's a simple algorithm to locate a character in this lib and fetch 32 bytes from the address to draw dots on the LCD. I've done such things with a graphical 128*64 COG LCD with 256KByte SPI memory. It was very interesting.


30 thousand Chinese characters? Must take a life time to learn how to read and write chinese.
 
HarveyH42 said:
30 thousand Chinese characters? Must take a life time to learn how to read and write chinese.

Didn't mean to scare ya, it was just a total number. 8192 characters will be enough for daily use. It's not so difficult as you thought to learn this language. My buddy Luciano has been here for two years, and now he's able to type SMS in Chinese, and on Windows Live as well. It's like drawing pictures for him.

Back to the topic. Put the characters in 16X16 dot matrix, it's 32*8192=262144 bytes = 256KB. It cost me $1 to buy a 512KB Flash memory when I built my own hardware library.
 
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