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| 1 | =============================================================== | ||
| 2 | == BT8XXGPIO driver == | ||
| 3 | == == | ||
| 4 | == A driver for a selfmade cheap BT8xx based PCI GPIO-card == | ||
| 5 | == == | ||
| 6 | == For advanced documentation, see == | ||
| 7 | == http://www.bu3sch.de/btgpio.php == | ||
| 8 | =============================================================== | ||
| 9 | |||
| 10 | |||
| 11 | A generic digital 24-port PCI GPIO card can be built out of an ordinary | ||
| 12 | Brooktree bt848, bt849, bt878 or bt879 based analog TV tuner card. The | ||
| 13 | Brooktree chip is used in old analog Hauppauge WinTV PCI cards. You can easily | ||
| 14 | find them used for low prices on the net. | ||
| 15 | |||
| 16 | The bt8xx chip does have 24 digital GPIO ports. | ||
| 17 | These ports are accessible via 24 pins on the SMD chip package. | ||
| 18 | |||
| 19 | |||
| 20 | ============================================== | ||
| 21 | == How to physically access the GPIO pins == | ||
| 22 | ============================================== | ||
| 23 | |||
| 24 | The are several ways to access these pins. One might unsolder the whole chip | ||
| 25 | and put it on a custom PCI board, or one might only unsolder each individual | ||
| 26 | GPIO pin and solder that to some tiny wire. As the chip package really is tiny | ||
| 27 | there are some advanced soldering skills needed in any case. | ||
| 28 | |||
| 29 | The physical pinouts are drawn in the following ASCII art. | ||
| 30 | The GPIO pins are marked with G00-G23 | ||
| 31 | |||
| 32 | G G G G G G G G G G G G G G G G G G | ||
| 33 | 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 | ||
| 34 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 | ||
| 35 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ||
| 36 | --------------------------------------------------------------------------- | ||
| 37 | --| ^ ^ |-- | ||
| 38 | --| pin 86 pin 67 |-- | ||
| 39 | --| |-- | ||
| 40 | --| pin 61 > |-- G18 | ||
| 41 | --| |-- G19 | ||
| 42 | --| |-- G20 | ||
| 43 | --| |-- G21 | ||
| 44 | --| |-- G22 | ||
| 45 | --| pin 56 > |-- G23 | ||
| 46 | --| |-- | ||
| 47 | --| Brooktree 878/879 |-- | ||
| 48 | --| |-- | ||
| 49 | --| |-- | ||
| 50 | --| |-- | ||
| 51 | --| |-- | ||
| 52 | --| |-- | ||
| 53 | --| |-- | ||
| 54 | --| |-- | ||
| 55 | --| |-- | ||
| 56 | --| |-- | ||
| 57 | --| |-- | ||
| 58 | --| |-- | ||
| 59 | --| |-- | ||
| 60 | --| |-- | ||
| 61 | --| O |-- | ||
| 62 | --| |-- | ||
| 63 | --------------------------------------------------------------------------- | ||
| 64 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ||
| 65 | ^ | ||
| 66 | This is pin 1 | ||
| 67 | |||