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products:i2cspilcdbackpack:index.html [2010/11/02 01:37] ladyada |
products:i2cspilcdbackpack:index.html [2016/01/28 18:05] (current) |
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+ | ====== Introduction ====== | ||
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+ | {{ /products/i2cspilcdbackpack/i2cconnect_t.jpg |/products/i2cspilcdbackpack/i2cconnect.jpg}} | ||
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+ | LCDs are a fun and easy way to have your microcontroller project talk back to you. Character LCDs are common, and easy to get, available in tons of colors and sizes. [[http://www.ladyada.net/learn/lcd/charlcd.html|We've written tutorials on using character LCDs with an Arduino]] (or similar microcontroller) but find that the number of pins necessary to control the LCD can be restrictive, especially with ambitious projects. We wanted to make a 'backpack' (add-on circuit) that would reduce the number of pins without a lot of expense. | ||
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+ | By using simple i2c and SPI input/output expanders we have reduced the number of pins (only 2 pins are needed for i2c) while still making it easy to interface with the LCD. For Arduino users, we provide a easy-to-use library that is backwards compatible with projects using the '6 pin' wiring. | ||
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+ | {{ /products/i2cspilcdbackpack/i2cwire_t.jpg |/products/i2cspilcdbackpack/i2cwire.jpg}} | ||
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+ | For advanced users, this project can be used for general purpose I/O expansion, the MCP23008 has 8 i/o pins (7 are connected) with optional pullups, the SPI 74HC595 has 7 outputs. | ||
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+ | Assembled and tested backpacks are available for purchase for only $10 in the Adafruit shop! | ||
====== Which LCD to use ====== | ====== Which LCD to use ====== | ||
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If you have a hankering to use the backpack as a general purpose i2c expander, you should use the plain [[http://github.com/adafruit/MCP23008-library|MCP23008 library, also at github]]. Its for more advanced users, by the way. | If you have a hankering to use the backpack as a general purpose i2c expander, you should use the plain [[http://github.com/adafruit/MCP23008-library|MCP23008 library, also at github]]. Its for more advanced users, by the way. | ||
+ | ==== Optimized i2c library ==== | ||
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+ | **FalconFour** posted up a [[http://forums.adafruit.com/viewtopic.php?f=19&t=21586&p=113177|ultra-optimized high-speed i2c library, check it out for better performance!]] | ||
===== Hardware files ===== | ===== Hardware files ===== | ||
[[http://github.com/adafruit/i2c-SPI-LCD-backpack|Eagle CAD format schematic and board layout file (as well as a PNG of the schematic) are all available in the GitHub repository]] | [[http://github.com/adafruit/i2c-SPI-LCD-backpack|Eagle CAD format schematic and board layout file (as well as a PNG of the schematic) are all available in the GitHub repository]] |