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author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-06 17:14:01 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-06 17:14:01 -0800 |
commit | db30c70575822cc84d87b5613c19cac24734b99f (patch) | |
tree | 82945ad5813bfe6633698233981d270b5f0a310b /Documentation/input/walkera0701.txt | |
parent | c861ea2cb2c25c1698734d9b0540a09e253690a1 (diff) | |
parent | 9334e90d5ac5ee1fa6d8b75acb7c64a8907787d1 (diff) | |
download | linux-db30c70575822cc84d87b5613c19cac24734b99f.tar.gz linux-db30c70575822cc84d87b5613c19cac24734b99f.tar.bz2 linux-db30c70575822cc84d87b5613c19cac24734b99f.zip |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (29 commits)
Input: i8042 - add Dell Vostro 1510 to nomux list
Input: gtco - use USB endpoint API
Input: add support for Maple controller as a joystick
Input: atkbd - broaden the Dell DMI signatures
Input: HIL drivers - add MODULE_ALIAS()
Input: map_to_7segment.h - convert to __inline__ for userspace
Input: add support for enhanced rotary controller on pxa930 and pxa935
Input: add support for trackball on pxa930 and pxa935
Input: add da9034 touchscreen support
Input: ads7846 - strict_strtoul takes unsigned long
Input: make some variables and functions static
Input: add tsc2007 based touchscreen driver
Input: psmouse - add module parameters to control OLPC touchpad delays
Input: i8042 - add Gigabyte M912 netbook to noloop exception table
Input: atkbd - Samsung NC10 key repeat fix
Input: atkbd - add keyboard quirk for HP Pavilion ZV6100 laptop
Input: libps2 - handle 0xfc responses from devices
Input: add support for Wacom W8001 penabled serial touchscreen
Input: synaptics - report multi-taps only if supported by the device
Input: add joystick driver for Walkera WK-0701 RC transmitter
...
Diffstat (limited to 'Documentation/input/walkera0701.txt')
-rw-r--r-- | Documentation/input/walkera0701.txt | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/Documentation/input/walkera0701.txt b/Documentation/input/walkera0701.txt new file mode 100644 index 000000000000..8f4289efc5c4 --- /dev/null +++ b/Documentation/input/walkera0701.txt @@ -0,0 +1,109 @@ + +Walkera WK-0701 transmitter is supplied with a ready to fly Walkera +helicopters such as HM36, HM37, HM60. The walkera0701 module enables to use +this transmitter as joystick + +Devel homepage and download: +http://zub.fei.tuke.sk/walkera-wk0701/ + +or use cogito: +cg-clone http://zub.fei.tuke.sk/GIT/walkera0701-joystick + + +Connecting to PC: + +At back side of transmitter S-video connector can be found. Modulation +pulses from processor to HF part can be found at pin 2 of this connector, +pin 3 is GND. Between pin 3 and CPU 5k6 resistor can be found. To get +modulation pulses to PC, signal pulses must be amplified. + +Cable: (walkera TX to parport) + +Walkera WK-0701 TX S-VIDEO connector: + (back side of TX) + __ __ S-video: canon25 + / |_| \ pin 2 (signal) NPN parport + / O 4 3 O \ pin 3 (GND) LED ________________ 10 ACK + ( O 2 1 O ) | C + \ ___ / 2 ________________________|\|_____|/ + | [___] | |/| B |\ + ------- 3 __________________________________|________________ 25 GND + E + + +I use green LED and BC109 NPN transistor. + +Software: + +Build kernel with walkera0701 module. Module walkera0701 need exclusive +access to parport, modules like lp must be unloaded before loading +walkera0701 module, check dmesg for error messages. Connect TX to PC by +cable and run jstest /dev/input/js0 to see values from TX. If no value can +be changed by TX "joystick", check output from /proc/interrupts. Value for +(usually irq7) parport must increase if TX is on. + + + +Technical details: + +Driver use interrupt from parport ACK input bit to measure pulse length +using hrtimers. + +Frame format: +Based on walkera WK-0701 PCM Format description by Shaul Eizikovich. +(downloaded from http://www.smartpropoplus.com/Docs/Walkera_Wk-0701_PCM.pdf) + +Signal pulses: + (ANALOG) + SYNC BIN OCT + +---------+ +------+ + | | | | +--+ +------+ +--- + +Frame: + SYNC , BIN1, OCT1, BIN2, OCT2 ... BIN24, OCT24, BIN25, next frame SYNC .. + +pulse length: + Binary values: Analog octal values: + + 288 uS Binary 0 318 uS 000 + 438 uS Binary 1 398 uS 001 + 478 uS 010 + 558 uS 011 + 638 uS 100 + 1306 uS SYNC 718 uS 101 + 798 uS 110 + 878 uS 111 + +24 bin+oct values + 1 bin value = 24*4+1 bits = 97 bits + +(Warning, pulses on ACK ar inverted by transistor, irq is rised up on sync +to bin change or octal value to bin change). + +Binary data representations: + +One binary and octal value can be grouped to nibble. 24 nibbles + one binary +values can be sampled between sync pulses. + +Values for first four channels (analog joystick values) can be found in +first 10 nibbles. Analog value is represented by one sign bit and 9 bit +absolute binary value. (10 bits per channel). Next nibble is checksum for +first ten nibbles. + +Next nibbles 12 .. 21 represents four channels (not all channels can be +directly controlled from TX). Binary representations ar the same as in first +four channels. In nibbles 22 and 23 is a special magic number. Nibble 24 is +checksum for nibbles 12..23. + +After last octal value for nibble 24 and next sync pulse one additional +binary value can be sampled. This bit and magic number is not used in +software driver. Some details about this magic numbers can be found in +Walkera_Wk-0701_PCM.pdf. + +Checksum calculation: + +Summary of octal values in nibbles must be same as octal value in checksum +nibble (only first 3 bits are used). Binary value for checksum nibble is +calculated by sum of binary values in checked nibbles + sum of octal values +in checked nibbles divided by 8. Only bit 0 of this sum is used. + |