Difference between revisions of "SPI LCD"
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#REDIRECT [[LCD]] |
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[[File:SPI_LCD.jpg|thumb|300px|alt=The SPI_LCD board|The SPI_LCD board]] |
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This is the documentation page for the SPI_LCD board. |
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== Overview == |
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== Assembly instructions == |
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The board comes assembled. No assembly required. |
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=== Possible Configurations === |
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The board could be configured with software for I2C. |
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== External resources == |
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=== Datasheets === |
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[http://www.atmel.com/Images/doc8006.pdf The datasheet of the Attiny44 processor] that is the "brains" of the board. |
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SPI connector: |
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[http://www.batsocks.co.uk/readme/isp_headers.htm We use the 6-pin header]. The pin labeled "RESET" when the connector is used as ICSP header should be labeled "slave select" when used for SPI datatransfer. |
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== Additional software == |
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=== Related projects === |
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== Pinout == |
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=== LEDs === |
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== Jumper settings == |
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There are two solder jumpers. The one between the two 6-pin SPI connectors controls the function of the SPI connector nearest the I2C connectors. |
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In the default configuration the second SPI connector is a daisy-chain connector for the SPI bus. |
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In the other configuration, the second SPI connector is the ICSP connector. |
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The second solder jumper connects "rs" and "vo" of the LCD together (and to one pin of the attiny44 controller on the board) in the default configuration. |
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In the other configuration, the pin used for SPI slave select can be used as the RS pin. This is used in the I2C configuration. |
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See [[solder jumpers]] for more information on how to change the setting. |
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== Programming == |
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To display a string on the LCD, just send over SPI the same bytes you would send to LCD, prefixed with the address of the LCD (the default address is 0x82). |
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Bytes above 0xf0 are "special". |
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0xf0 <xy> is set cursor. the <xy> byte is 3 bit line number and 5 bit position number. This addressing allows up to 8 lines of 32 characters. |
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0xf1 is clear LCD. |
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0xf2 <addr> is "set address". If you want to change the address the module reacts to. The address is stored in eeprom, and will remain this way after a powercycle. |
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0xf3 <contrast> is "set contrast". This will set the contrast to the value you specify. 0x40 is the default that works fine for the LCDs that we have. |
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0xf4 <backlight> is the "set backlight intensity" command. This will set the backlight intensity to the value specified. |
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0xf5 <byte> will send the byte as a command to the HD44780. You need this for example to use the user-defined characters. |
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0xff <byte> will send the byte to the LCD without special character processing. This allows you to send codes 0xf0 through 0xff to the LCD if required. |
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Other bytes are reserved and are currently implemented as a no-op. |
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== The software == |
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== Default operation == |
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== Future hardware enhancements == |
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== Future software enhancements == |
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== Changelog == |
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=== 1.2 === |
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* Initial public release |
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Latest revision as of 15:51, 21 May 2012
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