63 lines
		
	
	
		
			4.0 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			63 lines
		
	
	
		
			4.0 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
===================================================================
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A driver for a selfmade cheap BT8xx based PCI GPIO-card (bt8xxgpio)
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===================================================================
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For advanced documentation, see http://www.bu3sch.de/btgpio.php
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A generic digital 24-port PCI GPIO card can be built out of an ordinary
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Brooktree bt848, bt849, bt878 or bt879 based analog TV tuner card. The
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Brooktree chip is used in old analog Hauppauge WinTV PCI cards. You can easily
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find them used for low prices on the net.
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The bt8xx chip does have 24 digital GPIO ports.
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These ports are accessible via 24 pins on the SMD chip package.
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How to physically access the GPIO pins
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======================================
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The are several ways to access these pins. One might unsolder the whole chip
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and put it on a custom PCI board, or one might only unsolder each individual
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GPIO pin and solder that to some tiny wire. As the chip package really is tiny
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there are some advanced soldering skills needed in any case.
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The physical pinouts are drawn in the following ASCII art.
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The GPIO pins are marked with G00-G23::
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                                           G G G G G G G G G G G G     G G G G G G
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                                           0 0 0 0 0 0 0 0 0 0 1 1     1 1 1 1 1 1
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                                           0 1 2 3 4 5 6 7 8 9 0 1     2 3 4 5 6 7
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           | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
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           ---------------------------------------------------------------------------
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         --|                               ^                                     ^   |--
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         --|                               pin 86                           pin 67   |--
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         --|                                                                         |--
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         --|                                                               pin 61 >  |-- G18
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         --|                                                                         |-- G19
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         --|                                                                         |-- G20
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         --|                                                                         |-- G21
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         --|                                                                         |-- G22
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         --|                                                               pin 56 >  |-- G23
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         --|                                                                         |--
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         --|                           Brooktree 878/879                             |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|                                                                         |--
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         --|   O                                                                     |--
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         --|                                                                         |--
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           ---------------------------------------------------------------------------
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           | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
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           ^
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           This is pin 1
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