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@@ -4,3 +4,7 @@ *.o *.pyc *.pyo + +*.aux +*.log +*.pdf diff --git a/protocol.tex b/protocol.tex new file mode 100644 index 0000000..a5828e0 --- /dev/null +++ b/protocol.tex @@ -0,0 +1,148 @@ +\documentclass[11pt]{article} +\usepackage{xltxtra} +\usepackage{longtable} +\usepackage[usenames,dvipsnames]{xcolor} +\usepackage[font=small,labelfont=bf]{caption} +\setmainfont[Mapping=tex-text]{Delicious-Roman} +\setlength{\parindent}{0pt} +\setlength{\parskip}{6pt} + +\newsavebox\TBox +\def\textoverline#1{\savebox\TBox{#1}% + \makebox[0pt][l]{#1}\rule[1.1\ht\TBox]{\wd\TBox}{0.4pt}} + +\begin{document} +\title{subbus protocol} +\maketitle + +\section{packet types} + +\begin{table}[h] + \caption{subbus packets} + \begin{tabular}{rll} + address (hex) & usage & mode \\ + \hline + \texttt{100-00000} & time & src-periodic \\ + \texttt{4c0-0\textcolor{blue}{B}\textcolor{blue}{AAA}} & + discovery/info (request) & request/response \\ + \texttt{cc0-\textcolor{blue}{SS}\textcolor{blue}{AAA}} & + light (data transport to destination) & src-event, dst-periodic \\ + \texttt{e60-00\textcolor{blue}{AAA}} & + sensors (data transport from source) & src-periodic + \end{tabular} +\end{table} + +\section{addressing} + +Sensors and lights share a 12-bit address space, located in the CAN address at +the final 12 bit of the extended ID. The address contained in the CAN extended +ID specifies the device address concerned with the first byte of the data, the +following bytes are associated with the addresses following after. It is +therefore possible to set 8 lights with one packet. + +Information about the device can be requested with the discovery protocol. One +sensor/light may occupy more than one byte of data space, the device then +occupies multiple addresses because otherwise there would be a collision. The +discovery information indicates the number of bytes used by the device. + +\section{time protocol} + +TBA + +\section{discovery protocol} + +The discovery protocol uses a CAN Remote Frame/RTR based request-response +protocol. The querier sends an RTR frame to the discovery address; the device +responds with the same address and the data payload. + +(Future extension: the querier could send a regular frame to the discovery +address to write configuration/set options.) + +Discovery data consists of 16 information sub-blocks that are addressed with +bit 16-19 of the CAN extended ID. Block 0 is the root information block and +describes generic device properties. Block 8-15 carry a string description +of the device. The meaning of the remaining blocks depends on the root +information block. + +\subsection{packet format} + +Information request (RTR frame): +\begin{verbatim} +0100 1100 000_ / 00 bbbb aaaa aaaa aaaa / RTR +4 c 0 / 0 sub deviceaddr +\end{verbatim} + +Information response: +\begin{verbatim} +0100 1100 000_ / 00 bbbb aaaa aaaa aaaa / <data> +4 c 0 / 0 sub deviceaddr +\end{verbatim} + +\begin{itemize} +\item \texttt{bbbb} selects one of the 16 information sub-blocks. +\item \texttt{aaaa aaaa aaaa} is the device address. +\end{itemize} + +\subsection{information blocks} +\subsubsection{root block} + +The root information block describes generic device properties and should +always be queried to determine device characteristics: + +\begin{table}[h]\tt + \caption{\textnormal{information block 0 contents (root)}} + \begin{tabular}{rrl} + offset & type & field \\ + \hline + 0 & uint8\_t & \textnormal{actor type} \\ + 1 & uint8\_t & \textnormal{sensor type} \\ + 2 & uint8\_t & \textnormal{flags / reserved} \\ + 3 & uint8\_t & \textnormal{data size (1-8 bytes)} \\ + 4 & uint16\_t & \textnormal{sublab grid location} + \end{tabular} +\end{table} + +\subsubsection{type codes} + +Actor type codes (byte 0): + +\begin{longtable}{rl} + type code & type \\ + \hline + \texttt{00} & none (sensor or no function) \\ + \hline + \texttt{01} & light fixture, dimmable \\ + \texttt{02} & light fixture, not dimmable \\ + \texttt{03} & relais \\ + \hline + \texttt{ff} & custom / broken / ... +\end{longtable} + +Sensor type codes (byte 1): + +\begin{longtable}{rl} + type code & type \\ + \hline + \texttt{00} & none (actor or no function) \\ + \hline + \texttt{01} & light dimming readback sensor \\ + \texttt{02} & temperature sensor \\ + \texttt{03} & generic single-bit digital input \\ + \hline + \texttt{ff} & custom / broken / ... +\end{longtable} + +\section{sublab running nodes} +\begin{longtable}{rlll} + address & actor type & sensor type & node \\ + \hline + \texttt{100} & \texttt{00}: --- & \texttt{03}: digital & door: left wing \\ % & {\footnotesize \parbox{5em}{0: open,\\1: closed}} \\ + \texttt{101} & \texttt{00}: --- & \texttt{03}: digital & door: light barrier \\% & {\footnotesize \parbox{5em}{0: blocked,\\1: normal}} \\ + \texttt{102} & \texttt{00}: --- & \texttt{03}: digital & door: lock bolt \\ % & {\footnotesize \parbox{5em}{0: open,\\1: closed}} \\ + \texttt{103} & \texttt{00}: --- & \texttt{03}: digital & door: right wing \\ % & {\footnotesize \parbox{5em}{0: open,\\1: closed}} \\ + \hline + \texttt{440}-\texttt{47f} & \texttt{01}: dimmable & \texttt{01}: dimread & DALI bus mapping +\end{longtable} + + +\end{document} |