AbioWire user manual
Contents
1. owserver A server that allows multiple client programs to access the 1 Wire hardware These programs support a uniform command line syntax for specifying which 1 Wire adapters to detect and to expose For the AbioWire the i2c command line option is of importance Suppose you want to set up a web server that listens to port 80 Suppose the AbioWire is connected to BSC1 of the computer Enter the following command as root in the bin directory of owfs owhttpd p 80 i2c dev i2c 1 0 i2c dev i2c 1 1 i2c dev i2c 1 2 The dev i2c lt n gt lt i gt syntax denotes offset lt n gt from I2C address 0011000b on 12C bus of lt i gt The mentioned command line syntax thus tells owhttpd to look for 1 Wire controllers at addresses 0011000b 0011001b and 0011010b on the I2C bus of BSC1 The type of 1 Wire controller doesn t need to be specified the owfs software will distinguish between a DS2482 800 chip and a DS2482 100 chip Refer to the owfs documentation for more information 12 User Manual AbioWire 7 ESD Lightning Protection When you re planning to expose your 1 Wire network to the open air or an hostile environment ESD and nearby lightning strikes may hit your 1 Wire network and destroy the AbioWire and 1 Wire slaves in the process We strongly advice to protect your AbioWire if such problems are real Here s an example circuit to protect a 1 Wire adapter Note that for the correct functioning of the circuit a2. Direct I O Direct I O means the programs that run on your BCM2835 based computer directly communicate with the AbioWire from user mode using the first serial controller BSCO or the second serial controller BSC1 on the BCM2835 application processor Obviously using direct I O is appropriate when no I2C driver is loaded or at least the BSC that connects to the AbioWire is not under control of any I2C driver Direct I O requires root privileges IMPORTANT Do not force the programs to use direct I O if I2C drivers are present Doing so may disrupt the proper working of the I2C drivers and subsequently hang or crash the operating system User Manual 9 sae Q Abio Wire e b e i2c dev Interface I2C driver support in Linux includes a driver named i2c dev This driver offers a file interface to the I2C adapters from user mode through files in the dev directory These files are named dev i2c lt n gt where lt n gt is a number starting from zero If the i2c dev interface is not present you can activate it by running the following commands as root modprobe i2c bcm2708 modprobe i2c dev The following files will be created dev i2c 0 i2c dev interface for BSCO dev i2c 1 i2c dev interface for BSC1 Normally access to these files requires root privileges Revision of your BCM2835 based Computer There are currently two main revisions of the computer The GPIO pins are not compatible between the
3. Weather station Home automation 2 Technical Specifications Dimensions 73 mm x 60 mm x 22 mm WxDxH Weight 27 g without battery RTC backup power 10 years 4 User Manual AbioWire 3 Installation AbiowWire First of all place a CR2032 battery in the battery holder on the backside of the AbioWire Note that when no battery is present the AbioWire will work except the real time clock won t keep the time when the system is powered down The AbioWire has a 2x13 pin female header that fits perfectly on your BCM2835 based computer Be sure you connect the AbioWire in such a way it hovers over the computer as shown in the picture to the right A dedicated enclosure for the combo is available The enclosure ensures the AbioWire fits correctly on the computer If you decide to provide your own enclosure or no enclosure at all then be sure to fix the AbioWire in such a way its backside can t touch the computer Enclosure An enclosure specifically designed for the combo is available The enclosure comes with holes on top for connecting 1 Wire devices and I2C devices to the dedicated pin headers The AbioWire has three protrusions that aid in mounting the card in a fixed position The dedicated enclosure provides the right holes for these protrusions User Manual 5 AbioWire Bill of Materials Description T
4. at the top and an M3 countersunk hex screw 9 at the bottom DO NOT exert too much force when tightening the screws Stick a rubber foot on each M3 countersunk hex screw 9 on the bottom panel User Manual AbioWire 4 AbioWire Board Overview ECC a Aney Description I2C connector DS2482 100 1 Wire controller C connector DS2482 800 1 Wire controller A connectors DS2482 800 1 Wire controller B connectors GPIO female connector RTC backup power battery 3 V type CR2032 I2C Connector K18 Mark Description 5V 2 GND 3 SDA 4 SCL Connection to the I2C bus on the AbioWire This I2C bus operates at 5 V User Manual AbioWire 1 Wire Connector K1 K17 Description 5V DQ 2 GND 3 This connector is typically used to connect a 1 Wire channel to a 1 Wire slave with a similar connector or a breakout board 5 I2C Bus Slave Addresses The I2C bus on the AbioWire interconnects your BCM2835 based computer with a set of I2C slave devices The slave addresses are Address Slave Device 1010001b PCF2129A real time clock 0011000b 1 Wire controller A DS2482 800 8 channels 0011001b 1 Wire controller B DS2482 800 8 channels 0011010b 1 Wire controller C DS2482 100 1 channel Real time Clock The PCF2129A is a real time clock and calendar with an integrated temperature compensated crystal oscillator and
5. a 32 768 kHz quartz crystal The PCF2129A has a backup battery switch over circuit a programmable watchdog function a timestamp function and many other features The board has a holder for a CR2032 battery that functions as backup power for the PCF2129A 1 Wire Controllers The three 1 Wire controllers allow software to communicate with three 1 Wire slaves concurrently The 1 Wire controllers provide a total of seventeen 1 Wire buses 8 User Manual AbioWire 6 Software Overview The AbioWire is supported by a number of software packages that run on your BCM2835 based computer with Linux for ARM installed This document makes the following assumptions You ve installed Debian6 Linux or a derivative distribution on the SD card of your BCM2835 based computer You ve a personal log in that s not root You know how to run programs as root sudo command setuid access right flag You know how to log in as root log in prompt the su command This document describes commands entered at the command prompt When entering a command at the prompt of your personal log in the document uses the notation For example sudo owsenum A command entered at the prompt of the root log in is written with the notation For example owsenum Accessing I2C from Software Software has two ways of accessing the I2C hardware on your BCM2835 based computer Direct I O Using the Linux i2c dev interface
6. reliable earth connection is required computer chassis mains earth connector grounding pin 1 Wire Network 1N5404 1 5KE10ACCT 10V 1500W You can opt to protect 1 Wire slaves as well Here s an example circuit to protect a 1 Wire slave from certain destructive discharges on the 1 Wire network 1N4004 1 Wire Network lt Oo zZ H 12V 1W The diagrams presented here are example circuits It s the end user s responsibility to provide the required protection measures to prevent the AbioWire from being destroyed by electrical discharges and similar phenomenons User Manual 13 AbioWire 8 Disclaimer Axiris products are not designed authorized or warranted to be suitable for use in space nautical space military medical life critical or safety critical devices or equipment Axiris products are not designed authorized or warranted to be suitable for use in applications where failure or malfunction of an Axiris product can result in personal injury death property damage or environmental damage Axiris accepts no liability for inclusion or use of Axiris products in such applications and such inclusion or use is at the customer s own risk Should the customer use Axiris products for such application the customer shall indemnify and hold Axiris harmless against all claims and damages 9 Contact Information Official website http www axiris be be 14 User Manual
7. 2 800 chip and a DS2482 100 chip Enumerating 1 Wire Slaves To enumerate all 1 Wire slaves connected to the AbioWire User Manual 11 AbioWire owsenum bscdetect abiowire Reading 1 Wire Sensors To read out your 1 Wire sensor devices you first create a topology file that describes your 1 Wire networks Once the file has been created you feed it to program owsrds that will read out the actual sensor data Run as root owsenum bscdetect abiowire hub topo mynetworks txt owsrds bscdetect abiowire topo mynetworks txt The topology file needs to be created only once You can simply run owsrds periodically using cron for example to read out the sensor data You should recreate a topology file only when you change the topology of the 1 Wire sensor devices on your 1 Wire networks If you reconnect your 1 Wire networks to different channel connectors on the AbioWire don t worry The owsrds program will detect your networks and access the correct channel for each network Package owfs The AbioWire can be used with owfs the 1 Wire File System This software package is available from the following website http www owfs org The owfs software includes programs that expose the 1 Wire hardware in a variety of ways to the system owfs Creates a file system in a specified mount directory This program requires software package libfuse owhttpd Sets up a web server owftpd Sets up an FTP server
8. AbioWire 1 Wire Card for BCM2835 based computer User Manual July 2013 AbioWire Table of Contents 1 Features 4 2 Technical Specifications 4 3 Installation 5 AbioWire 5 Enclosure 5 Bill of Materials 6 Assembly Instructions 6 4 AbioWire 7 Board Overview 7 I2C Connector K18 7 1 Wire Connector K1 K17 8 5 I12C Bus 8 Slave Addresses 8 Real time Clock 8 1 Wire Controllers 8 6 Software 9 Overview 9 Accessing I2C from Software 9 Direct I O 9 i2c dev Interface 10 Revision of your BCM2835 based Computer 10 Real time Clock 10 Package ows 11 Installation 11 Specifying the Hardware 11 Enumerating 1 Wire Slaves 11 Reading 1 Wire Sensors 12 Package owfs 12 7 ESD Lightning Protection 13 8 Disclaimer 14 9 Contact Information 14 2 User Manual AbioWire Revision History Date Authors Description 2013 04 13 Peter S heeren First release 2013 07 09 Peter S heeren User Manual Second release AbioWire 1 Features Three 1i Wire controllers providing a total of seventeen 1 Wire channels Connector for I2C bus operating at 5 V Battery backed up real time clock and calendar with integrated temperature compensated crystal oscillator and a 32 768 kHz quartz crystal Compact footprint due to the use of SMD components Free software Works with the Axiris ows software package Works with the owfs software package Applications include
9. computer Run the install sh script in the context of your user account to install the ows group of programs in Linux Be sure to run the installation script from the command line rather than the file manager The script will sudo and as such the system may ask for the root password The ows package is installed in directory opt ows You ll have to cd to this directory to run the programs Specifying the Hardware To see the outcome of the BSC detection procedure run the following command as root owsenum bscdetect v The ows programs accept a standard set of options for specifying 1 Wire adapters Options Description bscdetect abiowire Auto detect BSC and interfacing type bsc 0 abiowire Use direct I O with AbioWire on BSC 0 bsc 1 abiowire Use direct I O with AbioWire on BSC 1 i2cdev dev i2c 0 abiowire Use i2c dev with AbioWire on BSC 0 i2cdev dev i2c 1 abiowire Use i2c dev with AbioWire on BSC 1 It s also possible to work with individual 1 Wire controllers of the AbioWire Options Description bscdetect ds2482 24 Auto detect BSC and interfacing type use the first 1 Wire controller I2C address is 24 bsc 0 ds2482 25 Use direct I O with the second 1 Wire controller on BSC 0 i2cdev dev i2c 1 ds2482 26 Use i2c dev with the third 1 Wire controller on BSC 1 You don t need to specify the type of 1 Wire controller the ows software will distinguish between a DS248
10. ransparent acrylic top panel Black acrylic bottom panel Transparent acrylic side panel audio video Transparent acrylic side panel HDMI Opaque acrylic side panel LAN USB Opaque acrylic side panel USB Micro B Rubber feet M3 hex screws top side OLMINIA N A WI Ne M3 countersunk hex screws bottom side p oO Spacers gt YY LY HINT Did you notice the rubber band that came with the package You can use it to hold together the assembly when you ve completed step 5 of the assembly instructions In doing so driving the screws will be much easier a a VY amp we ac Assembly Instructions 1 2 Remove the protective films from the acrylic panels Mount the AbioWire on the BCM2835 based computer as described earlier 2 You may have to leave a small gap between the card s connector and the base of the computer s GPIO pins in order to fit the card perfectly in the case 3 Mount the side panels 3 4 5 6 around the combo Place the assembly on the bottom panel 2 Make sure the air vents are closest to the LAN and USB panel 5 5 Mount the top panel 1 on top of the assembly Insert a spacer 10 in each corner between the top panel and the bottom panel Drive an M3 hex screw 8
11. se revisions Although the incompatibility doesn t affect the AbioWire hardware it does affect the software as follows Revision 1 The GPIO header pins 3 and 5 are wired to BSCO of the BCM2835 Revision 2 The GPIO header pins 3 and 5 are wired to BSC1 of the BCM2835 A number of programs are able to auto detect the revision of the computer and as such the BSC to use If you re using the ows package run the following program as root owsenum bscdetect v There are three possible outcomes a The program has detected direct I O Detecting BSC Adding i2cbus 0 bsc 1 b The program has detected the i2c dev driver is present Detecting BSC Adding i2cbus 0 i2c dev dev i2c 1 c The program has determined it s not running on a BCM2835 based computer Detecting BSC BCM2835 not detected skipping devices for bscdetect Real time Clock You can install the abiortc package to take advantage of the real time clock It available from the Axiris website S m 0 User Manual AbioWire Package ows This software package for 1 Wire is provided by Axiris It s available from the Axiris website The ows programs support several 1 Wire adapters and run on a variety of systems This document provides a quick guide for most common tasks for your AbioWire Refer to the ows documentation for more information Installation Unpack the ows package in a local directory in your home directory on your BCM2835 based
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