Re: [Emc-users] scale/encoder
Gentlemen, I just checked one channel. The best I could tell I have 1 wave/.001 of travel. thanks Stuart -- dos centavos -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
Stuart Stevenson wrote: Gentlemen, I just checked one channel. The best I could tell I have 1 wave/.001 of travel So, reading all quadrature transitions, that gives you .00025 resolution. Jon -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
hi gene would u share the size stepper motor u use, the type of controller u use and the current draw of the motors? I remember looking at ur web page once and seeing a picture of ur z axis setup. is that info still available??? thanks Bill -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] scale/encoder
Gentlemen, I have a manual CMM with scales. The display box is very old and almost functional. I would like to replace it with EMC2. Simple enough except for the scale feedback. The scale feedback is four sine waves at 0, 90, 180 and 270. These are, I think, approx 1 volt magnitude. What can I use to get this into EMC2 in a usable fashion. The original display has an 'amplifier, check, divide' board. I don't know the resolution of the sine wave. I have an sn7404n chip and a couple germanium diodes hooked to a bread board. I don't see anything out of the chip. I was expecting a pulse that would allow me to determine the resolution. At this time I have exceeded my electronics capabilities. Is there a chip or reasonable board I can use to change the sine waves to pulse or quadrature? thanks Stuart -- dos centavos -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
Stuart Apologies if this is stating the obvious, but the existing board almost certainly uses the amplitude of the Sin/Cos to interpolate the basic counts and so get a useful accuracy out of the scale. Heidenhain often have a ruling of 20 micrometres so with quadrature, discarding the analogue information, you only get 5 micron resolution. John Prentice - Original Message - From: Stuart Stevenson stus...@gmail.com To: EMC2-Users-List Emc-users@lists.sourceforge.net Sent: Friday, October 29, 2010 5:58 PM Subject: [Emc-users] scale/encoder Gentlemen, I have a manual CMM with scales. The display box is very old and almost functional. I would like to replace it with EMC2. Simple enough except for the scale feedback. The scale feedback is four sine waves at 0, 90, 180 and 270. These are, I think, approx 1 volt magnitude. What can I use to get this into EMC2 in a usable fashion. The original display has an 'amplifier, check, divide' board. I don't know the resolution of the sine wave. I have an sn7404n chip and a couple germanium diodes hooked to a bread board. I don't see anything out of the chip. I was expecting a pulse that would allow me to determine the resolution. At this time I have exceeded my electronics capabilities. Is there a chip or reasonable board I can use to change the sine waves to pulse or quadrature? thanks Stuart -- dos centavos -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On Fri, Oct 29, 2010 at 11:58:10AM -0500, Stuart Stevenson wrote: Gentlemen, I have a manual CMM with scales. The display box is very old and almost functional. I would like to replace it with EMC2. Simple enough except for the scale feedback. The scale feedback is four sine waves at 0, 90, 180 and 270. These are, I think, approx 1 volt magnitude. What can I use to get this into EMC2 in a usable fashion. The original display has an 'amplifier, check, divide' board. I don't know the resolution of the sine wave. I have an sn7404n chip and a couple germanium diodes hooked to a bread board. I don't see anything out of the chip. I was expecting a pulse that would allow me to determine the resolution. At this time I have exceeded my electronics capabilities. Is there a chip or reasonable board I can use to change the sine waves to pulse or quadrature? thanks Stuart I have a glass scale that gives a weird analog sine wavey signal. I was able to find some conditioned quadrature inside the amplifier box, and I ran that into a mesa card. I think there were only two sines 90 degrees apart though, so the conditioning was probably simple zero crossing detection perhaps with a bit of hysteresis. With your four signals maybe you just have the differential equivalent of mine? I suggest a little more deciphering of the amplifier board and/or poking with the scope. I'll try to help in two weeks if you don't get it by then. Chris -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On 29 October 2010 17:58, Stuart Stevenson stus...@gmail.com wrote: Is there a chip or reasonable board I can use to change the sine waves to pulse or quadrature? I suspect that the Pico Resolver converter might work, which I think is based on something like this http://docs-europe.origin.electrocomponents.com/webdocs/0e38/0900766b80e382db.pdf I think Mesa have a resolver converter too (or one on the cards). You can probably do 3 axes with a single Arduino, too, have a look at: http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?ResolverToQuadratureConverter -- atp -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On Fri, Oct 29, 2010 at 12:08 PM, Chris Radek ch...@timeguy.com wrote: I have a glass scale that gives a weird analog sine wavey signal. I was able to find some conditioned quadrature inside the amplifier box, and I ran that into a mesa card. I think there were only two sines 90 degrees apart though, so the conditioning was probably simple zero crossing detection perhaps with a bit of hysteresis. With your four signals maybe you just have the differential equivalent of mine? I suggest a little more deciphering of the amplifier board and/or poking with the scope. I'll try to help in two weeks if you don't get it by then. Chris I am attempting to get rid of the amplifier box as it is old. I have already replaced the caps in the power supply and this made it better. When the EMC group was here a couple years ago we got it adjusted and running. I have been chasing the adjustments to keep it from faulting. I adjust it and two day or two weeks later it is unusable because of a fault condition. I am working on this at this time because I know help will be here shortly. I just need to get fully prepared. :) thanks Stuart -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- dos centavos -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
John, For some the obvious is obvious. For me the obvious is not necessarily obvious. :) At this time I was only trying to find the resolution of one of the sine waves to see what I had to work with. thanks Stuart On Fri, Oct 29, 2010 at 12:05 PM, John Prentice j...@castlewd.freeserve.co.uk wrote: Stuart Apologies if this is stating the obvious, but the existing board almost certainly uses the amplitude of the Sin/Cos to interpolate the basic counts and so get a useful accuracy out of the scale. Heidenhain often have a ruling of 20 micrometres so with quadrature, discarding the analogue information, you only get 5 micron resolution. John Prentice - Original Message - From: Stuart Stevenson stus...@gmail.com To: EMC2-Users-List Emc-users@lists.sourceforge.net Sent: Friday, October 29, 2010 5:58 PM Subject: [Emc-users] scale/encoder Gentlemen, I have a manual CMM with scales. The display box is very old and almost functional. I would like to replace it with EMC2. Simple enough except for the scale feedback. The scale feedback is four sine waves at 0, 90, 180 and 270. These are, I think, approx 1 volt magnitude. What can I use to get this into EMC2 in a usable fashion. The original display has an 'amplifier, check, divide' board. I don't know the resolution of the sine wave. I have an sn7404n chip and a couple germanium diodes hooked to a bread board. I don't see anything out of the chip. I was expecting a pulse that would allow me to determine the resolution. At this time I have exceeded my electronics capabilities. Is there a chip or reasonable board I can use to change the sine waves to pulse or quadrature? thanks Stuart -- dos centavos -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- dos centavos -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On Fri, Oct 29, 2010 at 12:13 PM, Andy Pugh a...@andypugh.fsnet.co.ukwrote: On 29 October 2010 17:58, Stuart Stevenson stus...@gmail.com wrote: Is there a chip or reasonable board I can use to change the sine waves to pulse or quadrature? I suspect that the Pico Resolver converter might work, which I think is based on something like this http://docs-europe.origin.electrocomponents.com/webdocs/0e38/0900766b80e382db.pdf I have some of the Pico resolver converter boards. Jon E. - do you think they will work? I think Mesa have a resolver converter too (or one on the cards). I have a 5i23 - will it do this? You can probably do 3 axes with a single Arduino, too, have a look at: http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?ResolverToQuadratureConverter thanks Stuart -- dos centavos -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On Fri, Oct 29, 2010 at 06:13:48PM +0100, Andy Pugh wrote: On 29 October 2010 17:58, Stuart Stevenson stus...@gmail.com wrote: ?Is there a chip or reasonable board I can use to change the sine waves to pulse or quadrature? I suspect that the Pico Resolver converter might work I'm pretty sure these scales are optical. If it's the one I remember fiddling with, it's got light bulbs. I suspect the signals are just unconditioned light level detection. I'm not sure I know the right terminology to describe it, but they use a second piece of glass with the same pitch (?) lines in front of the master one. The second glass is at a slight angle so as you watch the light shining through it as you move the head, there is something like a moire pattern (?) that makes large areas of light and dark move perpendicular to the head's motion. It is these lines that are detected optically. For this reason I doubt there is interpolation. I bet the lines are the resolution of the device. I think they were too fine to see by naked eye. I bet very basic signal conditioning (thresholding) will be adequate to read this at full resolution. Chris -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On Fri, 29 Oct 2010, Stuart Stevenson wrote: Date: Fri, 29 Oct 2010 12:37:44 -0500 From: Stuart Stevenson stus...@gmail.com Reply-To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net To: Enhanced Machine Controller (EMC) emc-users@lists.sourceforge.net Subject: Re: [Emc-users] scale/encoder On Fri, Oct 29, 2010 at 12:13 PM, Andy Pugh a...@andypugh.fsnet.co.ukwrote: On 29 October 2010 17:58, Stuart Stevenson stus...@gmail.com wrote: Is there a chip or reasonable board I can use to change the sine waves to pulse or quadrature? I suspect that the Pico Resolver converter might work, which I think is based on something like this http://docs-europe.origin.electrocomponents.com/webdocs/0e38/0900766b80e382db.pdf I have some of the Pico resolver converter boards. Jon E. - do you think they will work? I think Mesa have a resolver converter too (or one on the cards). I have a 5i23 - will it do this? The 5I23 can work with the resolver interface card (7I49) but this would need firmware modifications for DC exitation like your scale uses (sine and cosine signals with no carrier) But as Chris says if interpolation is not needed, a simple comparator would do to convert the signals to TTL quadrature. Can you slowly move .010 or so and count the peaks? if the resolution or your display is more than 4X the number of peaks from one signal then interpolation is needed. You can probably do 3 axes with a single Arduino, too, have a look at: http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?ResolverToQuadratureConverter thanks Stuart -- dos centavos -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your ()_() signature to help him gain world domination. -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On Fri, Oct 29, 2010 at 1:22 PM, Chris Radek ch...@timeguy.com wrote: On Fri, Oct 29, 2010 at 06:13:48PM +0100, Andy Pugh wrote: On 29 October 2010 17:58, Stuart Stevenson stus...@gmail.com wrote: ?Is there a chip or reasonable board I can use to change the sine waves to pulse or quadrature? I suspect that the Pico Resolver converter might work I'm pretty sure these scales are optical. If it's the one I remember fiddling with, it's got light bulbs. I suspect the signals are just unconditioned light level detection. I'm not sure I know the right terminology to describe it, but they use a second piece of glass with the same pitch (?) lines in front of the master one. The second glass is at a slight angle so as you watch the light shining through it as you move the head, there is something like a moire pattern (?) that makes large areas of light and dark move perpendicular to the head's motion. It is these lines that are detected optically. For this reason I doubt there is interpolation. I bet the lines are the resolution of the device. I think they were too fine to see by naked eye. I bet very basic signal conditioning (thresholding) will be adequate to read this at full resolution. Yes the scales are optical as you describe. I changed the bulbs and set the gap and angle for the greatest signal strength. I have no idea of the basic resolution. That is what I am trying to find out at this time. Chris -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- dos centavos -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On 29 October 2010 19:32, Peter C. Wallace p...@mesanet.com wrote: The 5I23 can work with the resolver interface card (7I49) but this would need firmware modifications for DC exitation like your scale uses (sine and cosine signals with no carrier) At that point you could strip down my Arduino code to remove the PWM generation, take off the no-longer required filter/amplifier and simply keep the analogue sampling and arctan calculation. Then it would simply measure 6 voltages (sin and cos for three channels), calculate angle and output the results as quadrature pulses. You could re-jig for 16-bit A to D too (I have it at 10 bits for speed). Even if Chris is right that there is no interpolation, at $20 an Arduino is a very simple way to measure 6 analogue voltages, threshold them, and pass it to digital. -- atp -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On Fri, Oct 29, 2010 at 02:54:19PM -0500, Stuart Stevenson wrote: Yes the scales are optical as you describe. I changed the bulbs and set the gap and angle for the greatest signal strength. I have no idea of the basic resolution. That is what I am trying to find out at this time. Have you tried to count the fringes going by as you give it a little shove while an indicator is against it? Seems pretty possible. Maybe a .001 move (tenths indicator)? I bet you'll come up with 2500/inch or 6350/inch or some other nice round number. -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On Fri, Oct 29, 2010 at 3:49 PM, Chris Radek ch...@timeguy.com wrote: On Fri, Oct 29, 2010 at 02:54:19PM -0500, Stuart Stevenson wrote: Yes the scales are optical as you describe. I changed the bulbs and set the gap and angle for the greatest signal strength. I have no idea of the basic resolution. That is what I am trying to find out at this time. Have you tried to count the fringes going by as you give it a little shove while an indicator is against it? Seems pretty possible. Maybe a .001 move (tenths indicator)? I will check this before I go the Arduino route. I may be back there later today to check this. thanks Stuart I bet you'll come up with 2500/inch or 6350/inch or some other nice round number. -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- dos centavos -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On Fri, Oct 29, 2010 at 3:07 PM, Andy Pugh a...@andypugh.fsnet.co.ukwrote: On 29 October 2010 19:32, Peter C. Wallace p...@mesanet.com wrote: The 5I23 can work with the resolver interface card (7I49) but this would need firmware modifications for DC exitation like your scale uses (sine and cosine signals with no carrier) At that point you could strip down my Arduino code to remove the PWM generation, take off the no-longer required filter/amplifier and simply keep the analogue sampling and arctan calculation. Then it would simply measure 6 voltages (sin and cos for three channels), calculate angle and output the results as quadrature pulses. You could re-jig for 16-bit A to D too (I have it at 10 bits for speed). Even if Chris is right that there is no interpolation, at $20 an Arduino is a very simple way to measure 6 analogue voltages, threshold them, and pass it to digital. -- atp This sounds good - I will try it thanks Stuart -- dos centavos -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
Andy Pugh wrote: Even if Chris is right that there is no interpolation, at $20 an Arduino is a very simple way to measure 6 analogue voltages, threshold them, and pass it to digital. For those of us who grew up in the middle of the last century, this is the most amazing fact about today's microcontrollers. They are nearly always the most cost-effective solution to the problem at hand, even when the application seems too trivial to waste one on it. No matter your favorite microcontroller family, everyone should have a drawerful of different capability chips on hand. Now that I'm over the hill, I think about the number of times in my life I implemented yet another purpose-built, multi-package, hybrid, analog-digital solution where a single microcontroller would do. I also think about how many more things I could have achieved had I not had to spend so much time getting each hybrid solution right. Sigh. My vacuum tube-era engineer-dad once said to me, you whippersnappers will never know how good you have it. I wonder what the technology will be like when you find yourselves saying it to those who follow you. Regards, Kent -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On Fri, 2010-10-29 at 13:22 -0500, Chris Radek wrote: ... snip I'm not sure I know the right terminology to describe it, but they use a second piece of glass with the same pitch (?) lines in front of the master one. The second glass is at a slight angle so as you watch the light shining through it as you move the head, there is something like a moire pattern (?) that makes large areas of light and dark move perpendicular to the head's motion. It is these lines that are detected optically. For this reason I doubt there is interpolation. I bet the lines are the resolution of the device. I think they were too fine to see by naked eye. I bet very basic signal conditioning (thresholding) will be adequate to read this at full resolution. Chris ... snip Another possibility might be a vernier sensor. Over the span of four in-line sensors, there is a mask with a pitch of the scale pitch -1. This would present a dark region that would travel across the four sensor area. Each sensor would have a peak every scale line to line span/4 of movement. Another thought is that the designers might have tried to allow for variable bulb brightness, so two sets of two sensors are set up to have their peak and valley at the same location so the difference could be used as the signal threshold. How many bulbs are there? -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
On Friday, October 29, 2010 08:26:57 pm Kent A. Reed did opine: Andy Pugh wrote: Even if Chris is right that there is no interpolation, at $20 an Arduino is a very simple way to measure 6 analogue voltages, threshold them, and pass it to digital. For those of us who grew up in the middle of the last century, this is the most amazing fact about today's microcontrollers. They are nearly always the most cost-effective solution to the problem at hand, even when the application seems too trivial to waste one on it. No matter your favorite microcontroller family, everyone should have a drawerful of different capability chips on hand. Now that I'm over the hill, I think about the number of times in my life I implemented yet another purpose-built, multi-package, hybrid, analog-digital solution where a single microcontroller would do. I also think about how many more things I could have achieved had I not had to spend so much time getting each hybrid solution right. Sigh. My vacuum tube-era engineer-dad once said to me, you whippersnappers will never know how good you have it. I wonder what the technology will be like when you find yourselves saying it to those who follow you. Regards, Kent I would liked to have met your dad, Kent. He sounds like an old warhorse I'd like to trade battle stories with. For some things, it wasn't till we shut down the analog transmitter 18 months ago that the last vacuum tube was allowed to cool down for good. I saved a dud, non-rebuildable final tube from our old GE transmitter just so I could show it off to the younger set who will today, cheerfully use 8192 transistors in parallel to do what this tube did when it was fresh. A water cooled anode that required deionized water in the coolant system because the tubes anode had 7200 volts on it. This tube was rated to make 85 kilowatts (sync tip peak) of power in the low vhf band, but our transmitter let it relax with its feet up on the coffee table because we only needed 26.7 sync tip peak to make our power. Most 'engineers' don't know how to baby those big tubes use one up every 6 months at $7000 a rebuild. In the time since I became the CE at WDTV in 1984, I only used 3 of them. That was a significant reduction in the stations C.O.D.B. -- Cheers, Gene There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order. -Ed Howdershelt (Author) This PORCUPINE knows his ZIPCODE ... And he has VISA!! -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
-- Gary Fiber K8IZ GROL PG-19-6691 with shipboard radar endorsement Washington State resident -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
Chris Radek wrote: With your four signals maybe you just have the differential equivalent of mine? Yes, and one of the advantages of that is it gives a clear indication if the light bulb fails. All 4 signals go the same way and you lose the differential nature of the signals. (I will bet it DOES have an actual bulb, or was made just after the first LEDs came out, they used this in Allen-Bradley and other CNC controls as a fail-safe scheme.) Jon -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
Andy Pugh wrote: On 29 October 2010 17:58, Stuart Stevenson stus...@gmail.com wrote: Is there a chip or reasonable board I can use to change the sine waves to pulse or quadrature? I suspect that the Pico Resolver converter might work, which I think is based on something like this http://docs-europe.origin.electrocomponents.com/webdocs/0e38/0900766b80e382db.pdf No, unfortunately, these boards drive a rotary transformer-type device with an AC signal, and detect the resulting AC output, both amplitude and phase. It won't work with the photocell output of a glass scale. Jon -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] scale/encoder
Gene Heskett wrote: A water cooled anode that required deionized water in the coolant system because the tubes anode had 7200 volts on it. This tube was rated to make 85 kilowatts (sync tip peak) of power in the low vhf band, but our transmitter let it relax with its feet up on the coffee table because we only needed 26.7 sync tip peak to make our power. Up at Michigan State University's National Superconducting Cyclotron Lab they have two cyclotrons. Each has 3 transmitting tubes, as they have 6 Dees, 3 grounded and 3 live, with 120 degree phase relationship. Kind of like 3 phase mains power only at 14 MHz or something. The main DC supply is 18 KV at 42 amps. That is 756 KW of DC power! I know the smaller cyclotron has smaller transmitting tubes in it, but that averages out to 126 KW per tube! They really aren't very big, either. (Just to be clear, the 42 A is not the rating, it is the ACTUAL load as read off the meters.) Almost all of this power is turned into RF heating of the inside of the cyclotrons. Jon -- Nokia and ATT present the 2010 Calling All Innovators-North America contest Create new apps games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
