Changeset 14273 for firmware

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Timestamp:
Jul 17, 2012, 5:25:49 PM (7 years ago)
Message:
ShutterControlled, added tech details
File:
1 edited

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 r14272 \def\mysubsubsubsection#1{\paragraph{#1}\label{subsubsubsec: #1}{~}} \setcounter{secnumdepth}{5} \def\version{v0.1 Draft} \begin{document} \title{FACT Shutter User Guide - Draft} \title{FACT Shutter User Guide - \version} \author{V.~Boccone} % Dr. \maketitle \vspace*{-28mm} {\flushright \hfill{\bf FACT Shutter (ab)User Guide - Draft}\\ \hfill{\bf FACT Shutter (ab)User Guide - \version}\\ \hfill{\today}\\ \hfill{boccone@cern.ch}} The firmware can be uploaded in the Arduino through a standard RS232 serial port although an USB to Serial converter adapter is provided with the board. The firmware which is currently uploaded provide a simple web server with two button linked to the opening and closing commands of the shutter. \subsection{The motor controller board} \subsection{The motor controller shield} The motor controller shield is a {\bf Pololu Dual VNH5019 Motor Driver Shield\footnote{\href{http://www.pololu.com/catalog/product/2502}{http://www.pololu.com/catalog/product/2502}}}. The schematic of the shield and the layout of the connection are shown in Fig.\ref{figMotorShield} and Fig.\ref{figMotorShieldUse} respectively. \begin{figure}[b!] \centering \includegraphics[width=0.77\textwidth]{pololu_sch_small.png} \caption{\label{figMotorShield} {Diagram of the dual VHN5019 motor driver Arduino shield}} \end{figure} Each of the VHN-5019 is able to control a mid-high power motor using Pulse Width Modulation (PWM) and, in addition, grants the possibility of performing current sensing on the A0 (M1CS signal) and A1 (M2CS signal) pins of the Arduino board by embedding a current to voltage converter with a current sensing coefficient of 0.14 V/A. Each of the VHN-5019 is able to control - with few external components - a mid-high power motor using continuous current or Pulse Width Modulation (PWM) and - in addition - grants the possibility of performing the motor current sensing using the A0 ({\bf M1CS} signal) and A1 ({\bf M2CS} signal) Arduino analog inputs by embedding on the chip a current to voltage converter with a current sensing coefficient of 0.14 V/A. Other then the A0 and A1 Arduino analog inputs the shield uses three additional digital I/O Arduino ports for each motors. The {\bf MxINA} and {\bf MxINB} signals, connected to pins 2/3 for motor 1 and pins 7/8 for motor 2, define the status of each motor (on/off) while the {\bf MxPWM} signals, connected to pins 5 and 6 for motor 1 and motor 2 respectively, define the speed. The motors together with the main motor power supply (24~V) are connected to the front 6-ways connector as indicated in the Fig.\ref{figMotorShieldUse}. %In view of an - almost - completely remote operability of the FACT telescope the shutter %The new system was adapted as much as possible on the old mechanics.... %Each lid can move independently by a 55 mm stroke actuator which grant the necessary excursion to reach the $110^{\circ}$ which is required in order no to shadow the camera. \begin{figure}[b!] \centering \includegraphics[width=0.8\textwidth]{pololu_sch_small.png} \caption{\label{figMotorShield} {Diagram of the dual VHN5019 motor driver Arduino shield}} \end{figure} \begin{figure}[t!] \centering \end{figure} \subsection{Amplifier and filter shield} In view of low current measurement, two 10x amplifiers followed by each preceded by a low pass 2$^{nd}$ \mbox{($\nu_{cut}=1~$ kHz)} Butterworth filters were included on a custom circuit mounted as an Arduino shield. The diagram of the filter/amplifier Arduino shield is shown in Fig.\ref{figFilterShield}. The input current sensing signal is taken from the A0 and A1 analog Arduino pins while the amplified and filtered output is fed on the A4 and A5 analog pins respectively. The analog signals of the Hall position sensors are also fed a low pass 2$^{nd}$ \mbox{($\nu_{cut}=1~$ kHz)} Butterworth filters and their output is connected to the A2/A3 analog Arduino pins. The system is completed by a amplifier and filter shield which has the double task of:\begin{itemize} \item reducing the noise of the hall sensors accumulated over the 35 m of cables with a low-pass filter \mbox{($\nu_{\rm Low~Cut}=1~$ kHz)}; \item producing a second low current sensing measurement on pin A4 and A5 by amplifying ($\times 10$) and filtering \mbox{($\nu_{\rm Low~Cut}=1~$ kHz)} the signals on the A0 and A1 pins produced by the VHN-5019 chips. \end{itemize} The diagram of the filter/amplifier Arduino shield is shown in Fig.\ref{figFilterShield}. The design includes test pins and a set of jumper used for disable the amplification or the filter in case of need. \begin{figure}[t!] \centering \caption{\label{figFilterShield} {Diagram of the custom filter/amplifier Arduino shield}} \end{figure} %In view of low current measurement, two 10x amplifiers followed by each preceded by a low pass 2$^{nd}$ \mbox{($\nu_{cut}=1~$ kHz)} Butterworth filters were included on a custom circuit mounted as an Arduino shield. The diagram of the filter/amplifier Arduino shield is shown in Fig.\ref{figFilterShield}. The input current sensing signal is taken from the A0 and A1 analog Arduino pins while the amplified and filtered output is fed on the A4 and A5 analog pins respectively. % The analog signals of the Hall position sensors are also fed a low pass 2$^{nd}$ \mbox{($\nu_{cut}=1~$ kHz)} Butterworth filters and their output is connected to the A2/A3 analog Arduino pins. \subsection{Possible upgrades} The pin 4 and pin 9 Arduino I/O port were also connected to lemo cable in case - for example - of future wire coupling with other subsystems (i.e. the interlock system) \clearpage \section{Appearance} %\section{Diagram of the filter board}