## ## This file is part of the libsigrokdecode project. ## ## Copyright (C) 2012 Uwe Hermann ## Copyright (C) 2017 Kevin Redon ## ## This program is free software; you can redistribute it and/or modify ## it under the terms of the GNU General Public License as published by ## the Free Software Foundation; either version 2 of the License, or ## (at your option) any later version. ## ## This program is distributed in the hope that it will be useful, ## but WITHOUT ANY WARRANTY; without even the implied warranty of ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ## GNU General Public License for more details. ## ## You should have received a copy of the GNU General Public License ## along with this program; if not, see . ## ''' This protocol decoder handles the 1-Wire link layer. The 1-Wire protocol enables bidirectional communication over a single wire (and ground) between a single master and one or multiple slaves. The protocol is layered: - Link layer (reset, presence detection, reading/writing bits) - Network layer (skip/search/match device ROM addresses) - Transport layer (transport data between 1-Wire master and device) Sample rate: A sufficiently high samplerate is required to properly detect all the elements of the protocol. A lower samplerate can be used if the master does not use overdrive communication speed. The following minimal values should be used: - overdrive available: 2MHz minimum, 5MHz suggested - overdrive not available: 400kHz minimum, 1MHz suggested Channels: 1-Wire requires a single signal, but some master implementations might have a separate signal used to deliver power to the bus during temperature conversion as an example. - owr (1-Wire signal line) Options: 1-Wire is an asynchronous protocol with fixed timing values, so the decoder must know the samplerate. Two speeds are available: normal and overdrive. The decoder detects when switching from one to another but the user can set which to start decoding with: - overdrive (to decode starting with overdrive speed) ''' from .pd import Decoder