Re: [Owfs-developers] connecting many DS2408
Le 14 Février 2006 16:04, Paul Alfille a écrit : Paul Alfille wrote: I was incorrect in my earlier note about the polling frequency. The DS2408 has a latch, accessible through OWFS, that will save the button press. This will greatly diminish the chance of missing a button press and reduce the polling frequency. I looked at the documentation, and it's even better than I remembered. There is an alarm state triggered by a change in any of the pins. ... The advantage of this is that you will only see the triggered switches (only they appear in the alarm directory) and the latches make catching button presses easier. The only limits are now the latency between finding a button press and giving feedback. Paul, do you know if there's a timestamp associated with the alarms? I need to know when the switches were pressed, without polling a lot. -- Marc --- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnkkid0944bid$1720dat1642 ___ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
RE: [Owfs-developers] connecting many DS2408
No timestamp. You can easily poll every second, however. Is that fine enough resolution? Paul -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Marc Lavallée Sent: Monday, February 27, 2006 9:50 AM To: owfs-developers@lists.sourceforge.net Subject: Re: [Owfs-developers] connecting many DS2408 Le 14 Février 2006 16:04, Paul Alfille a écrit : Paul Alfille wrote: I was incorrect in my earlier note about the polling frequency. The DS2408 has a latch, accessible through OWFS, that will save the button press. This will greatly diminish the chance of missing a button press and reduce the polling frequency. I looked at the documentation, and it's even better than I remembered. There is an alarm state triggered by a change in any of the pins. ... The advantage of this is that you will only see the triggered switches (only they appear in the alarm directory) and the latches make catching button presses easier. The only limits are now the latency between finding a button press and giving feedback. Paul, do you know if there's a timestamp associated with the alarms? I need to know when the switches were pressed, without polling a lot. -- Marc --- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=kkid0944bid$1720dat1642 ___ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers --- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnkkid0944bid$1720dat1642 ___ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
Re: [Owfs-developers] connecting many DS2408
Am Dienstag, 14. Februar 2006 20:12 schrieb Marc Lavallée: Le 13 Février 2006 15:03, Jan Kandziora a écrit : Am Montag, 13. Februar 2006 19:46 schrieb Marc Lavallée: I'm new to the 1-wire technology. I'd like to interface over 30 DS2408 on a 1-wire bus, using ordinary ethernet cables, arranged in a topology of 2 or 3 branches with 10 or 15 daisy-chained devices. Branches are a big problem for the onewire hardware. According to Dallas'/Maxim's own investigations, it's best to avoid star-bus topologies at all cost. You have three options: 1. Change the star-bus into a looped-bus topology: Use four wires per cable, two for the forward-direction to the branch end, two for the reverse direction back to the root and connect it there with the forward direction of the next brach. Maybe I would understand better with a schematic. HOSTforward-direction 1W-+ 1W_GND+| || Branch_1 +-+| |+-+ || reverse-direction || || || |+-+ +-+| || Branch_2 +-+| |+-+ || || || || |+-+ +-+| || Branch_3 +-+| |+-+ || || || 2. Use the DS2409 chip and switch branches. Something like: http://www.hobby-boards.com/catalog/product_info.php?products_id=1511 ? You could build yourself, as only the DS2409 chip is needed. It's not so hard to weld a TSOC6 package (unlike SO16) by hand, and you could even get the 2 needed DS2409 parts as samples from Maxim. Kind regards Jan -- Really, I'm not out to destroy Microsoft. That will just be a completely unintentional side effect. -- Linus Torvalds --- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnkkid3432bid#0486dat1642 ___ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
Re: [Owfs-developers] connecting many DS2408
On Tuesday 14 February 2006 02:12 pm, Marc Lavallée wrote: Le 13 Février 2006 15:03, Jan Kandziora a écrit : Am Montag, 13. Februar 2006 19:46 schrieb Marc Lavallée: I'm new to the 1-wire technology. I'd like to interface over 30 DS2408 on a 1-wire bus, using ordinary ethernet cables, arranged in a topology of 2 or 3 branches with 10 or 15 daisy-chained devices. Branches are a big problem for the onewire hardware. According to Dallas'/Maxim's own investigations, it's best to avoid star-bus topologies at all cost. You have three options: 1. Change the star-bus into a looped-bus topology: Use four wires per cable, two for the forward-direction to the branch end, two for the reverse direction back to the root and connect it there with the forward direction of the next brach. Maybe I would understand better with a schematic. 2. Use the DS2409 chip and switch branches. This would be a rather slow solution for polling. The Link-Hub has electrical partitioning but a unified bus topology that would be a little faster. Something like: http://www.hobby-boards.com/catalog/product_info.php?products_id=1511 ? 3. Use several host adapters. Is OWFS able to manage several adapters? Absolutely! You can have OWFS connect to the several adapters, and it will give a unified view, as well as (optionally) a separated view. I.e. you can call owfs /dev/ttyS0 /dev/ttyS1 /dev/ttyS2 /1wire Then 'ls 1wire/29.*' to get all the DS2408 adapters (0x29 is the family code) or 'ls 1wire/bus.0/29.*' to get the DS2408s on the first adapter. You can also run several instances of OWFS: owfs /dev/ttyS0 /1wire/Line0 owfs /dev/ttyS1 /1wire/Line1 owfs /dev/ttyS2 /1wire/Line2 and 'ls /1wire.Line?/29.*' to get a unified view or address each directory (and thus owfs instance and adapter) independently. Note, in all these cases, the adapter can be serial, USB, or remote (via owserver). This last method might be a little faster, but only works for the filesystem interface. We don't currently allow more than one OWFS instance for the language bindings. It's really hard to monitor keypresses that way with a non-realtime OS. Networked peripherals makes things even worse. You have to do it by hardware. The simplest idea is to use the edge detector circuits built into the DS2408. That will give you a button was pressed since last check signal for each button. That might be enough. If it's not, then I can add a hardware latch in the circuit (a flip-flop?), because what I need to know is which key was pressed first. Paul Alfille wrote: I was incorrect in my earlier note about the polling frequency. The DS2408 has a latch, accessible through OWFS, that will save the button press. This will greatly diminish the chance of missing a button press and reduce the polling frequency. I looked at the documentation, and it's even better than I remembered. There is an alarm state triggered by a change in any of the pins. # loop through all switches for x in /1wire/29.* ; do # trigger if any latch (better check this) echo 1 $x/set_alarm # set non-conducting to allow sensing echo 0 $x/PIO.BYTE done #Loop forever while : ; do # Loop through alarms for x in /1wire/alarm/29.* ; do # Run a program with the switch name and the Latch state (button presses) ProcessSwitch `basename $x` `cat $x/latch.BYTE` # Reset the latches and clear the alarm echo 1 $x/latch.BYTE done #optional pause done The advantage of this is that you will only see the triggered switches (only they appear in the alarm directory) and the latches make catching button presses easier. The only limits are now the latency between finding a button press and giving feedback. Note that this scheme lends itself very well to partitioning. Several instances of script/owfs/adapter can each run simultaneously. Only the ProcessSwitch function has to worrt about locking shared resources. The /1wire directory can be accessed by other processes at the same time to give feedback, monitor temperatures or whatever. That seems to be the most elegant solution but I still don't understand how it works. At this point I should order a 1-Wire interface and a few 2408 in order to experiment. Yup, that's the best idea. The DS9090K kit comes with a USB adapter, a little wiring area, and a selection of chips. $65 -- Paul Alfille --- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnkkid3432bid#0486dat1642 ___ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
RE: [Owfs-developers] connecting many DS2408
Hello from Gregg C Levine For my part, I'd rather give my money to Maxim-IC for their DS9090K, because I've got something of a good history with them. Also I reviewed the contents of the kit via the Maxim-IC website, and as it happens yes you are right Paul regarding the prototyping area. And I might add that they provide a set of sockets for their (to me annoying) TSOC parts on the board. I've looked at the contents of the Hobby Boards site, and I confess I'm not impressed. Most of what they sell seems to be aimed towards the hobbyist who does not want to build his own One-Wire hardware. Well, with regards to their LCD display stuff that I would buy. It is one device that I'm not comfortable with trying to build. I should also add that if we are going to assist the correspondent in working out the particulars for the many DS2408 project we should also track down a company who will mount the DS2408 parts to boards on a relatively cheap basis. Other then Hobby Boards that is. (To assist with code creation of course.) --- Gregg C Levine [EMAIL PROTECTED] --- Remember the Force will be with you. Always. Obi-Wan Kenobi -Original Message- From: [EMAIL PROTECTED] [mailto:owfs-developers- [EMAIL PROTECTED] On Behalf Of Paul Alfille Sent: Tuesday, February 14, 2006 4:05 PM To: owfs-developers@lists.sourceforge.net Subject: Re: [Owfs-developers] connecting many DS2408 On Tuesday 14 February 2006 02:12 pm, Marc Lavallée wrote: Le 13 Février 2006 15:03, Jan Kandziora a écrit : Am Montag, 13. Februar 2006 19:46 schrieb Marc Lavallée: I'm new to the 1-wire technology. I'd like to interface over 30 DS2408 on a 1-wire bus, using ordinary ethernet cables, arranged in a topology of 2 or 3 branches with 10 or 15 daisy-chained devices. Branches are a big problem for the onewire hardware. According to Dallas'/Maxim's own investigations, it's best to avoid star-bus topologies at all cost. You have three options: 1. Change the star-bus into a looped-bus topology: Use four wires per cable, two for the forward-direction to the branch end, two for the reverse direction back to the root and connect it there with the forward direction of the next brach. Maybe I would understand better with a schematic. 2. Use the DS2409 chip and switch branches. This would be a rather slow solution for polling. The Link-Hub has electrical partitioning but a unified bus topology that would be a little faster. Something like: http://www.hobby-boards.com/catalog/product_info.php?products_id=1511 ? 3. Use several host adapters. Is OWFS able to manage several adapters? Absolutely! You can have OWFS connect to the several adapters, and it will give a unified view, as well as (optionally) a separated view. I.e. you can call owfs /dev/ttyS0 /dev/ttyS1 /dev/ttyS2 /1wire Then 'ls 1wire/29.*' to get all the DS2408 adapters (0x29 is the family code) or 'ls 1wire/bus.0/29.*' to get the DS2408s on the first adapter. You can also run several instances of OWFS: owfs /dev/ttyS0 /1wire/Line0 owfs /dev/ttyS1 /1wire/Line1 owfs /dev/ttyS2 /1wire/Line2 and 'ls /1wire.Line?/29.*' to get a unified view or address each directory (and thus owfs instance and adapter) independently. Note, in all these cases, the adapter can be serial, USB, or remote (via owserver). This last method might be a little faster, but only works for the filesystem interface. We don't currently allow more than one OWFS instance for the language bindings. It's really hard to monitor keypresses that way with a non-realtime OS. Networked peripherals makes things even worse. You have to do it by hardware. The simplest idea is to use the edge detector circuits built into the DS2408. That will give you a button was pressed since last check signal for each button. That might be enough. If it's not, then I can add a hardware latch in the circuit (a flip-flop?), because what I need to know is which key was pressed first. Paul Alfille wrote: I was incorrect in my earlier note about the polling frequency. The DS2408 has a latch, accessible through OWFS, that will save the button press. This will greatly diminish the chance of missing a button press and reduce the polling frequency. I looked at the documentation, and it's even better than I remembered. There is an alarm state triggered by a change in any of the pins. # loop through all switches for x in /1wire/29.* ; do # trigger if any latch (better check this) echo 1 $x/set_alarm # set non-conducting to allow sensing echo 0 $x/PIO.BYTE done #Loop forever while : ; do # Loop through alarms for x in /1wire/alarm/29.* ; do # Run a program with the switch name and the Latch state (button presses) ProcessSwitch `basename $x` `cat $x/latch.BYTE` # Reset the latches and clear the alarm echo 1 $x/latch.BYTE done #optional
Re: [Owfs-developers] connecting many DS2408
On Monday 13 February 2006 01:46 pm, Marc Lavallée wrote: I'm new to the 1-wire technology. I'd like to interface over 30 DS2408 on a 1-wire bus, using ordinary ethernet cables, arranged in a topology of 2 or 3 branches with 10 or 15 daisy-chained devices. The total length of the cables could be over 100 meters. I need to monitor momentary push-buttons connected to the I/O pins of the 2408 and I need to know about the chronology of their status (pressed or released). It would work on Linux, and eventually on OSX. What are my options? Thanks for your help -- Marc I presume you are asking if OWFS can support this configuration. 1. The DS2408 is fully supported, both reading the PIO status and switching devices. In fact all 8 switches can be read atomically. 2. Your application is most fragile at the momentary push-button presses. Missed pushes will frustrate your users. That implies polling for push buttons, presumably fast enough not to miss any presses. 3. You probably want to partition your problem, both separate busses for network configuration and to speed polling. OWFS supports this vary well. You can even reduce the span of your network by placing embedded devices (the ASUS WL-WL500G Deluxe or some of the WRT54G work brilliantly, either wired or wirelessly. 4. You can either use the filesystem interface, or one of the language bindings. 5. There are clearly people willing to help. Paul Alfille --- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnkkid3432bid#0486dat1642 ___ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
Re: [Owfs-developers] connecting many DS2408
On Monday 13 February 2006 01:46 pm, Marc Lavallée wrote: I'm new to the 1-wire technology. I'd like to interface over 30 DS2408 on a 1-wire bus, using ordinary ethernet cables, arranged in a topology of 2 or 3 branches with 10 or 15 daisy-chained devices. The total length of the cables could be over 100 meters. I need to monitor momentary push-buttons connected to the I/O pins of the 2408 and I need to know about the chronology of their status (pressed or released). It would work on Linux, and eventually on OSX. What are my options? Thanks for your help -- Marc One other thought: the DS2423 (used in the wind speed meter) has two contact counters, which would make the polling problem easier. Also, Louis Swart's LCD controller has 4 PIO counter pins that count button presses. Neither of these would record order of presses withough rapid polling. Paul Alfille --- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnkkid3432bid#0486dat1642 ___ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
Re: [Owfs-developers] connecting many DS2408
--On 02/13/2006 01:46:34 PM -0500 MarcLavallée wrote: I'm new to the 1-wire technology. I'd like to interface over 30 DS2408 on a 1-wire bus, using ordinary ethernet cables, arranged in a topology of 2 or 3 branches with 10 or 15 daisy-chained devices. The total length of the cables could be over 100 meters. I need to monitor momentary push-buttons connected to the I/O pins of the 2408 and I need to know about the chronology of their status (pressed or released). It would work on Linux, and eventually on OSX. What are my options? Thanks for your help -- Marc Marc, What you are doing is certainly doable. A few things that others didn't say: With 30 sensors, I would not depend on parasitic power. It means bringing a 3.3 or 5V line to the chips. This allows you to ignore the charging time if you want to do near continuous polling. Others may have a different opinion on this, and it may be less of an issue with the 2408 than temp sensors. With power, you have an odd number of lines so you can get noise pickup on the wire. I found it easier to pull the power and ground in a true star, and only daisy chain the signal line. I have done tests with 140m in this way and no observed problems. I also have a chain in service that has much more than 100m hanging off a single chain, but I don't have a TDR to measure the true length. In one part is has 3 runs that go ~15m from the star point to the sensors, so that 90m of bus length right there. IButtonlink has a hub product in either serial or ethernet flavors. This is a 1-wire interface and produces 4 1-wire buses with +5v and +12v. It does not emulate the logic of the 1-wire switch, which is contorted at best, but rather makes all the sensors available with no additional coding. I have a serial version. Paul has added support for the ethernet version as well. best of luck, jerry Jerry Scharf laguna way consulting --- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnkkid3432bid#0486dat1642 ___ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
