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Diffstat (limited to 'Documentation/video4linux/hauppauge-wintv-cx88-ir.txt')
| -rw-r--r-- | Documentation/video4linux/hauppauge-wintv-cx88-ir.txt | 54 |
1 files changed, 0 insertions, 54 deletions
diff --git a/Documentation/video4linux/hauppauge-wintv-cx88-ir.txt b/Documentation/video4linux/hauppauge-wintv-cx88-ir.txt deleted file mode 100644 index a2fd363c4..000000000 --- a/Documentation/video4linux/hauppauge-wintv-cx88-ir.txt +++ /dev/null @@ -1,54 +0,0 @@ -The controls for the mux are GPIO [0,1] for source, and GPIO 2 for muting. - -GPIO0 GPIO1 - 0 0 TV Audio - 1 0 FM radio - 0 1 Line-In - 1 1 Mono tuner bypass or CD passthru (tuner specific) - -GPIO 16(i believe) is tied to the IR port (if present). - ------------------------------------------------------------------------------------- - ->From the data sheet: - Register 24'h20004 PCI Interrupt Status - bit [18] IR_SMP_INT Set when 32 input samples have been collected over - gpio[16] pin into GP_SAMPLE register. - -What's missing from the data sheet: - -Setup 4KHz sampling rate (roughly 2x oversampled; good enough for our RC5 -compat remote) -set register 0x35C050 to 0xa80a80 - -enable sampling -set register 0x35C054 to 0x5 - -Of course, enable the IRQ bit 18 in the interrupt mask register .(and -provide for a handler) - -GP_SAMPLE register is at 0x35C058 - -Bits are then right shifted into the GP_SAMPLE register at the specified -rate; you get an interrupt when a full DWORD is received. -You need to recover the actual RC5 bits out of the (oversampled) IR sensor -bits. (Hint: look for the 0/1and 1/0 crossings of the RC5 bi-phase data) An -actual raw RC5 code will span 2-3 DWORDS, depending on the actual alignment. - -I'm pretty sure when no IR signal is present the receiver is always in a -marking state(1); but stray light, etc can cause intermittent noise values -as well. Remember, this is a free running sample of the IR receiver state -over time, so don't assume any sample starts at any particular place. - -http://www.atmel.com/dyn/resources/prod_documents/doc2817.pdf -This data sheet (google search) seems to have a lovely description of the -RC5 basics - -http://www.nenya.be/beor/electronics/rc5.htm and more data - -http://www.ee.washington.edu/circuit_archive/text/ir_decode.txt -and even a reference to how to decode a bi-phase data stream. - -http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm -still more info - |