Re: USB voltmeter or DAQ module, small, inexpensive, with OpenBSD support
Also if you can go with serial, there are loads of cheap digital voltmeters with serial interfaces. A while back I got a bunch of Metex ME-11 meters for our workshop, which have a DB9 connector. They come with windows/DOS software but I suspect the interface is reasonably universal (or at least basic). There are a lot of utilities around to talk to these (eg http://home.arcor.de/magnos/linux/metex/metex.html) which would probably build ok on OpenBSD. Of course you did say you needed to measure a few voltages, so with this you'd be limited by number of serial ports. Don't know if it would work for you, but it seemed like a possible option... On Fri, Jan 29, 2010 at 05:00:33PM +0100, Daniel Gracia Garallar wrote: With a proto board and some skills, you could build a serial system with a total cost around US$30, small enough to not even need a rail support. You could also try to hang on the I2C iface of your mainboard and add you own devices, but if you're not so much into electronics... Go the Arduino way; readily available, cheap as chips and infinite expansion boards. Ralph Becker-Szendy escribis: For one of my OpenBSD machines, I need to be able to measure a few analog voltages, and act on them in a control process. The requirements are quite simple compared to typical data acquisition: I absolutely need two voltage inputs, either 0-20V or 0-100mV; doesn't have to be differential, acquisition can be slow (1s is fine), and resolution can be as small as 10-12 bits (1% accuracy is more than good enough). A few extra input channels, more accuracy/resolution, and a few digital IOs wouldn't hurt, but are not necessary. DIN rail mounting and connection breakout would be nice, but can be improvised. On the software side, there will be OpenBSD, with ad-hoc monitoring and control scripts. With a little programming and script-writing, I can adapt anything that the OS can reasonably access. Now come the issues: I can't use PCI cards, only external units, most likely connected via USB (as Ethernet and serial are expensive or rare). And it needs to have some software support under OpenBSD - a Windows- or Linux-only solution doesn't work. And this application is not worth spending thousands of $$$. For Windows and LabView, solutions are easy to find (for example EMant300, DAQPodMX, a variety of Omega products). Does anyone now of a solution that would work with OpenBSD? -- - Graham Allan - I.T. Manager - al...@physics.umn.edu - (612) 624-5040 School of Physics and Astronomy - University of Minnesota -
Re: USB voltmeter or DAQ module, small, inexpensive, with OpenBSD support
+1 for ~US$40-50 you should be able to get a usb adapter and a couple of sensor IC's to play with. Never measured the voltage of something but the hobby boards temp/solar/humidity uses it for the humidity part (differential voltage I believe). man owsbm. The DS2438 it supports should be what you need. Oh, and of course, the most important part, it's supported by the sensors framework sa2 # sysctl hw.sensors|grep ow hw.sensors.owtemp0.temp0=21.50 degC (sn 0008014d1f8f) hw.sensors.owid0.raw0=2632185 (sn 002829f9) hw.sensors.owsbm0.temp0=21.09 degC (sn 00a8b940) hw.sensors.owsbm0.volt0=4.51 VDC (VDD) hw.sensors.owsbm0.volt1=1.43 VDC (VAD) hw.sensors.owsbm0.volt2=0.00 VDC (CR) noah P.S. I have no stake in hobby-boards but have ordered before from them. Good shop. Paul M wrote: OpenBSD has a driver for the Dallas OneWire protocol. man(4) onewire Dallas make adapters for USB and RS232, such as the DS9490R - google can find you a supplier, for example: http://www.hobby-boards.com/catalog/product_info.php?products_id=1503 There are all manner of 1wire chips avalable - hobby boards can help here if you dont want to build something from scratch. I havn't used these adapters, nor used 1wire on OpenBSD, nor dealt with hobby-boards.com, but I have used a 1wire A-D to read input multiple voltages on a dedicated system and it works very well. It should work very well on OpenBSD too. paulm On 29/01/2010, at 9:27 AM, Ralph Becker-Szendy wrote: For one of my OpenBSD machines, I need to be able to measure a few analog voltages, and act on them in a control process. The requirements are quite simple compared to typical data acquisition: I absolutely need two voltage inputs, either 0-20V or 0-100mV; doesn't have to be differential, acquisition can be slow (1s is fine), and resolution can be as small as 10-12 bits (1% accuracy is more than good enough). A few extra input channels, more accuracy/resolution, and a few digital IOs wouldn't hurt, but are not necessary. DIN rail mounting and connection breakout would be nice, but can be improvised. On the software side, there will be OpenBSD, with ad-hoc monitoring and control scripts. With a little programming and script-writing, I can adapt anything that the OS can reasonably access. Now come the issues: I can't use PCI cards, only external units, most likely connected via USB (as Ethernet and serial are expensive or rare). And it needs to have some software support under OpenBSD - a Windows- or Linux-only solution doesn't work. And this application is not worth spending thousands of $$$. For Windows and LabView, solutions are easy to find (for example EMant300, DAQPodMX, a variety of Omega products). Does anyone now of a solution that would work with OpenBSD? -- Ralph Becker-Szendyra...@lr.los-gatos.ca.us(408)395-1435 735 Sunset Ridge Road; Los Gatos, CA 95033
Re: USB voltmeter or DAQ module, small, inexpensive, with OpenBSD support
With a proto board and some skills, you could build a serial system with a total cost around US$30, small enough to not even need a rail support. You could also try to hang on the I2C iface of your mainboard and add you own devices, but if you're not so much into electronics... Go the Arduino way; readily available, cheap as chips and infinite expansion boards. Ralph Becker-Szendy escribis: For one of my OpenBSD machines, I need to be able to measure a few analog voltages, and act on them in a control process. The requirements are quite simple compared to typical data acquisition: I absolutely need two voltage inputs, either 0-20V or 0-100mV; doesn't have to be differential, acquisition can be slow (1s is fine), and resolution can be as small as 10-12 bits (1% accuracy is more than good enough). A few extra input channels, more accuracy/resolution, and a few digital IOs wouldn't hurt, but are not necessary. DIN rail mounting and connection breakout would be nice, but can be improvised. On the software side, there will be OpenBSD, with ad-hoc monitoring and control scripts. With a little programming and script-writing, I can adapt anything that the OS can reasonably access. Now come the issues: I can't use PCI cards, only external units, most likely connected via USB (as Ethernet and serial are expensive or rare). And it needs to have some software support under OpenBSD - a Windows- or Linux-only solution doesn't work. And this application is not worth spending thousands of $$$. For Windows and LabView, solutions are easy to find (for example EMant300, DAQPodMX, a variety of Omega products). Does anyone now of a solution that would work with OpenBSD?
Re: USB voltmeter or DAQ module, small, inexpensive, with OpenBSD support
On Thu, 28 Jan 2010 22:28:45 -0800 Raymond Lillard rlill...@sonic.net wrote: Ralph Becker-Szendy wrote: For one of my OpenBSD machines, I need to be able to measure a few analog voltages, and act on them in a control process. The requirements are quite simple compared to typical data acquisition: I absolutely need two voltage inputs, either 0-20V or 0-100mV; doesn't have to be differential, acquisition can be slow (1s is fine), and resolution can be as small as 10-12 bits (1% accuracy is more than good enough). A few extra input channels, more accuracy/resolution, and a few digital IOs wouldn't hurt, but are not necessary. DIN rail mounting and connection breakout would be nice, but can be improvised. On the software side, there will be OpenBSD, with ad-hoc monitoring and control scripts. With a little programming and script-writing, I can adapt anything that the OS can reasonably access. Now come the issues: I can't use PCI cards, only external units, most likely connected via USB (as Ethernet and serial are expensive or rare). And it needs to have some software support under OpenBSD - a Windows- or Linux-only solution doesn't work. And this application is not worth spending thousands of $$$. For Windows and LabView, solutions are easy to find (for example EMant300, DAQPodMX, a variety of Omega products). Does anyone now of a solution that would work with OpenBSD? Ralph, http://www.netburner.com/embedded_control.html The PK70 with the analog board will give you everything you asked for and quite a bit more at a hardware cost of US$400. This may be over-kill, and you will need to write a bit of code to run on the PK70. You will also need to add a voltage divider if you want to go the 20V route. The development environment is GCC based but unfortunately hosted on Windows :-(. I have rolled my own cross-compilers for other NB products on Linux, OpenBSD would probably be possible. The development environment is not needed once you have downloaded your code to flash on the PK70.It is probably not worth the trouble as your requirements are small, even though it's hard to be productive while holding your nose with one hand while typing with the other. I am assuming this is a hobby project and your time is free (as in beer). I have been using products from this company in volume for a decade. They are good guys with very solid products. I have no financial interest in the Netburner company. I notice you are local to me. Contact me by off-line by email if you want to talk about it by phone. Ray Small world... --I'm also in Los Gatos, so if you want to give me a ring, contact me off list. I'm guessing GPIB would be over-kill for your situation? I've got one National Instruments GPIB card for Sun (sbus) and a second for x86 (ISA). I think I might even have a NI PCI GPIB card around here somewhere. I believe I have I GPIB/Ethernet and GPIB/Serial bridges. I've always thought it might be fun to write OpenBSD drivers for the NI cards. GPIB might be old, but it's extremely useful. From what you wrote, I'd also guess you want to keep things *very* simple, so I doubt you'll be getting into driving lots of equipment in a manufacturing/test environment? --The only hint you gave to the contrary was the desire for DIN rail mounting? Depending on distance/environment requirements, serial can be a viable option for you, and is often less complex and less expensive than USB. -Jon
Re: USB voltmeter or DAQ module, small, inexpensive, with OpenBSD support
OpenBSD has a driver for the Dallas OneWire protocol. man(4) onewire Dallas make adapters for USB and RS232, such as the DS9490R - google can find you a supplier, for example: http://www.hobby-boards.com/catalog/product_info.php?products_id=1503 There are all manner of 1wire chips avalable - hobby boards can help here if you dont want to build something from scratch. I havn't used these adapters, nor used 1wire on OpenBSD, nor dealt with hobby-boards.com, but I have used a 1wire A-D to read input multiple voltages on a dedicated system and it works very well. It should work very well on OpenBSD too. paulm On 29/01/2010, at 9:27 AM, Ralph Becker-Szendy wrote: For one of my OpenBSD machines, I need to be able to measure a few analog voltages, and act on them in a control process. The requirements are quite simple compared to typical data acquisition: I absolutely need two voltage inputs, either 0-20V or 0-100mV; doesn't have to be differential, acquisition can be slow (1s is fine), and resolution can be as small as 10-12 bits (1% accuracy is more than good enough). A few extra input channels, more accuracy/resolution, and a few digital IOs wouldn't hurt, but are not necessary. DIN rail mounting and connection breakout would be nice, but can be improvised. On the software side, there will be OpenBSD, with ad-hoc monitoring and control scripts. With a little programming and script-writing, I can adapt anything that the OS can reasonably access. Now come the issues: I can't use PCI cards, only external units, most likely connected via USB (as Ethernet and serial are expensive or rare). And it needs to have some software support under OpenBSD - a Windows- or Linux-only solution doesn't work. And this application is not worth spending thousands of $$$. For Windows and LabView, solutions are easy to find (for example EMant300, DAQPodMX, a variety of Omega products). Does anyone now of a solution that would work with OpenBSD? -- Ralph Becker-Szendyra...@lr.los-gatos.ca.us(408)395-1435 735 Sunset Ridge Road; Los Gatos, CA 95033
Re: USB voltmeter or DAQ module, small, inexpensive, with OpenBSD support
Ralph Becker-Szendy wrote: For one of my OpenBSD machines, I need to be able to measure a few analog voltages, and act on them in a control process. The requirements are quite simple compared to typical data acquisition: I absolutely need two voltage inputs, either 0-20V or 0-100mV; doesn't have to be differential, acquisition can be slow (1s is fine), and resolution can be as small as 10-12 bits (1% accuracy is more than good enough). A few extra input channels, more accuracy/resolution, and a few digital IOs wouldn't hurt, but are not necessary. DIN rail mounting and connection breakout would be nice, but can be improvised. On the software side, there will be OpenBSD, with ad-hoc monitoring and control scripts. With a little programming and script-writing, I can adapt anything that the OS can reasonably access. Now come the issues: I can't use PCI cards, only external units, most likely connected via USB (as Ethernet and serial are expensive or rare). And it needs to have some software support under OpenBSD - a Windows- or Linux-only solution doesn't work. And this application is not worth spending thousands of $$$. For Windows and LabView, solutions are easy to find (for example EMant300, DAQPodMX, a variety of Omega products). Does anyone now of a solution that would work with OpenBSD? Ralph, http://www.netburner.com/embedded_control.html The PK70 with the analog board will give you everything you asked for and quite a bit more at a hardware cost of US$400. This may be over-kill, and you will need to write a bit of code to run on the PK70. You will also need to add a voltage divider if you want to go the 20V route. The development environment is GCC based but unfortunately hosted on Windows :-(. I have rolled my own cross-compilers for other NB products on Linux, OpenBSD would probably be possible. The development environment is not needed once you have downloaded your code to flash on the PK70.It is probably not worth the trouble as your requirements are small, even though it's hard to be productive while holding your nose with one hand while typing with the other. I am assuming this is a hobby project and your time is free (as in beer). I have been using products from this company in volume for a decade. They are good guys with very solid products. I have no financial interest in the Netburner company. I notice you are local to me. Contact me by off-line by email if you want to talk about it by phone. Ray
