From de3d27fc2badd4f2a992da5ff7f8bba3937016fe Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 4 Apr 2017 17:49:22 -0700 Subject: [PATCH] Input: walkera0701 - convert documentation into ReST format This file require minimum adjustments to be a valid ReST file. Do it, in order to be able to parse it with Sphinx. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Dmitry Torokhov --- Documentation/input/walkera0701.txt | 51 ++++++++++++++++++++--------- 1 file changed, 35 insertions(+), 16 deletions(-) diff --git a/Documentation/input/walkera0701.txt b/Documentation/input/walkera0701.txt index 49e3ac60dcef..2adda99ca717 100644 --- a/Documentation/input/walkera0701.txt +++ b/Documentation/input/walkera0701.txt @@ -1,3 +1,6 @@ +=========================== +Walkera WK-0701 transmitter +=========================== Walkera WK-0701 transmitter is supplied with a ready to fly Walkera helicopters such as HM36, HM37, HM60. The walkera0701 module enables to use @@ -10,7 +13,8 @@ or use cogito: cg-clone http://zub.fei.tuke.sk/GIT/walkera0701-joystick -Connecting to PC: +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, @@ -19,7 +23,8 @@ modulation pulses to PC, signal pulses must be amplified. Cable: (walkera TX to parport) -Walkera WK-0701 TX S-VIDEO connector: +Walkera WK-0701 TX S-VIDEO connector:: + (back side of TX) __ __ S-video: canon25 / |_| \ pin 2 (signal) NPN parport @@ -30,10 +35,10 @@ Walkera WK-0701 TX S-VIDEO connector: ------- 3 __________________________________|________________ 25 GND E - I use green LED and BC109 NPN transistor. -Software: +Software +======== Build kernel with walkera0701 module. Module walkera0701 need exclusive access to parport, modules like lp must be unloaded before loading @@ -44,7 +49,8 @@ be changed by TX "joystick", check output from /proc/interrupts. Value for -Technical details: +Technical details +================= Driver use interrupt from parport ACK input bit to measure pulse length using hrtimers. @@ -53,17 +59,29 @@ 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 - +---------+ +------+ - | | | | ---+ +------+ +--- +Signal pulses +------------- + +:: + + (ANALOG) + SYNC BIN OCT + +---------+ +------+ + | | | | + --+ +------+ +--- + +Frame +----- + +:: -Frame: SYNC , BIN1, OCT1, BIN2, OCT2 ... BIN24, OCT24, BIN25, next frame SYNC .. -pulse length: +pulse length +------------ + +:: + Binary values: Analog octal values: 288 uS Binary 0 318 uS 000 @@ -80,7 +98,8 @@ pulse length: (Warning, pulses on ACK are inverted by transistor, irq is raised up on sync to bin change or octal value to bin change). -Binary data representations: +Binary data representations +--------------------------- One binary and octal value can be grouped to nibble. 24 nibbles + one binary values can be sampled between sync pulses. @@ -100,10 +119,10 @@ 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: +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. - -- 2.20.1