Commit de3d27fc authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab Committed by Dmitry Torokhov
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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: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 730518f2
===========================
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.
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