Parallax - Anybody Home?
Kirk Fraser
Posts: 364
Although I understand your market direction toward toys and educational robots, why don't I see much going on with respect to serious industrial applications which would include more than 8 Bit A/D and D/A?·
Tracy has a great website for A/D but nobody including Parallax has anything on D/A yet.· You Parallax guys ever thought of·ordering a sample chip or two and trying something out?·· I'm sure you guys could find D/A Chips that would work on Stamps in a week or two.
My attempt fizzled so far (I·can't even get my·Tek scope to report anything close·to the program output)·but Tracy did a great job of giving help.· You ought to pay him to manage your customer support team·part time.·
As for me I've ordered samples from·the MAX line and am waiting for delivery.· i tried my BS2P40 on the TI D/A's and that did nothing differently.·
Tracy has a great website for A/D but nobody including Parallax has anything on D/A yet.· You Parallax guys ever thought of·ordering a sample chip or two and trying something out?·· I'm sure you guys could find D/A Chips that would work on Stamps in a week or two.
My attempt fizzled so far (I·can't even get my·Tek scope to report anything close·to the program output)·but Tracy did a great job of giving help.· You ought to pay him to manage your customer support team·part time.·
As for me I've ordered samples from·the MAX line and am waiting for delivery.· i tried my BS2P40 on the TI D/A's and that did nothing differently.·
Comments
Maybe you didn't mean it this way, but your post comes off as "I can't get his working... Maybe I can bully Parallax into figuring it out for me."
I too would like to see Parallax support industrial application more, and I have relayed that to Ken. But I would never do it in a public forum unless Parallax brought it up.
Bean.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"SX-Video·Module" Now available from Parallax for only $28.95
http://www.parallax.com/detail.asp?product_id=30012
Product web site: www.sxvm.com
Available now... SX-Video OSD module $59.95 www.sxvm.com
"Save your money. Pay with cash."
·
Kirk
I think the responsibility is primarily your own. I don't know what your background is, but it is pretty clear from your posts that you don't have much experience in electronics. There is probably one little thing that is making your circuit inoperable, but we have not stumbled across what that is, and you do not have the necessary troubleshooting skills. That the Tek 'scope does not report anything close to the program output is probably not the fault of the 'scope, nor of the Stamp, nor of Parallax, but it is your lack of knowledge of how to use the 'scope and maybe a bit of impatience and misplaced expectations. Same thing with the TI chip. Getting a new batch of chips from Maxim is not going to help with the fundamental problem. And you still have the interface to the proportional valves to design build and debug. Maybe a class at the local community college would help, where someone is there to look at what you are doing and lend a hand.
I do appreciate your frustration. In my last post about the Maxim DAC that I got working, I mentioned three initial frustrations I had to overcome before the chip started working. It is always like that. Things hardly ever work the first time. But with experience you learn what to look for, and persevere until you can say, aha with satisfaction.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tracy Allen
www.emesystems.com
That was NOT support... It was advise...
Bean.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"SX-Video·Module" Now available from Parallax for only $28.95
http://www.parallax.com/detail.asp?product_id=30012
Product web site: www.sxvm.com
Available now... SX-Video OSD module $59.95 www.sxvm.com
"Save your money. Pay with cash."
·
Actually a different set of chips might help.· The quality of the D/A chips I got from TI are lower than the quality of the TI A/D chip you recommend based on two observations:· They require a 2 volt reference voltage which they strongly recommended I buy from them instead of using your pot and capacitor solution in contrast your A/D circuit works fine with the same 5v chip supply wired to the reference pin.· Second, the switching of performing between A and B when the new chip was put in, indicating some of the chips act differently, hence weren't designed as well as the A/D which works fine.
I did take a Digital Electronics class at the local community college earlier this year and got an A-.· I was the one who introduced the teacher to your A/D chip and he thanked me for showing him the state of the art.· The class did teach me some things although at over $500 for the class and book plus transportation which is getting expensive, it's not something I want to spend that kind of money for again if I can help it.· I'd rather pay for a finished solution.
Ok, Bean, here's some advice from me.· Go to a Dollar Tree store and buy a new Bible for $1.· Read the 4 gospels and Revelation, praying that you and all 6+ Billion people on earth receive and fully believe Jesus Christ.· Continue obeying Jesus for the rest of your life or until you·ascend to God's throne, whichever comes first.
Kirk
Sid
I wore out my welcome over at the BasicX Yahoo site using a similar approach to yours.
This is a community and friendly relationships gain support. If you want 'bang for your buck' try to join.
The simple fact is that if you try to work with us, you will get more than you can almost anywhere else on the web. I am in Taiwan and I couldn't enjoy this hobby without good web support.· There are too many A/D chips and flavors for Parallax to provide a full inventory, so they chose an easy, cheap one for begineers.· It really is that simple.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
G. Herzog in Taiwan
Post Edited (Kramer) : 10/13/2005 7:16:54 AM GMT
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·1+1=10
This is a community. I maybe based in the US, but I, too, rely on the Forums for support. And advise. Please try to keep your posts more on topic, and yes even polite. I practically wore out my welcome in the original group by maintaining an attitude similar to yours.
They may tolerate my strangeness on a gaggle of groups on the same service as the old one, but only because I manage a few of them.·So please heed what·Kramer suggested.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Buck Rogers
www.gregg.levine.name
<edit>
Actually thinking about it, I have posted about testing 4-20ma current loops generated by stamp, if you search for that will find a rather long thread from several people.··Also last time I checked the projects forum had a good handful of industrial apps.
Industrial Control Text, v1.1
http://www.parallax.com/detail.asp?product_id=27341
Post Edited (Orion) : 10/12/2005 11:56:18 PM GMT
Kirk, you sure don't ACT like you are following your own advise.
My last word to this member (promise).
Bean.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"SX-Video·Module" Now available from Parallax for only $28.95
http://www.parallax.com/detail.asp?product_id=30012
Product web site: www.sxvm.com
Available now... SX-Video OSD module $59.95 www.sxvm.com
"Save your money. Pay with cash."
·
The search function on the forums IS something you can whine to Parallax about....
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax
If you have critisisms then they should be directed to Parallax directly and not on an open forum!
You'll find a lot of people on here willing to help in all manners....and No, they don't have [noparse][[/noparse]Parallax Employee] beside their names!
A lot of people spend time on these forums just reading what other people are going through in hopes of either lending a hand, or learning something themselves.
If you can't afford the $ to go to college classes, then set aside some time each day to peruse the forum and pick up little tidbits about other people's problems/successes.
I'm quite proud that I've been able to help on the odd occasion, but I lurk on here just about every day reading what people are doing.
So, flaming/ranting is no way to encourage help of any kind from anyone at all!
Politics and Religion should be kept out of any posts....unless the Pope were to get in to "Stampin"!! (ultrasonic detector in the big hat to avoid hitting doorways?)
Anyhow, humour aside (if it's at all funny haha)....the best way to get help is to post your problem in detail....the more info you provide, the more help you may get in response!
We've all been in the, "Dang, it'd be easier to have someone else do this..."! But if you mean that, then maybe electronic hobby building isn't for you....it really is about persistance and patience! (has almost nothing to do with skill and smarts....what's that quote about 1000monkeys on 1000typewriters??).....
Good luck
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·
Steve
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
If someone has not already done the thing you are asking about, and there is a troubleshooting issue, that someone has to take valuable time to peruse the data sheet and read between the lines and come up with possbible solutions. Or set up the same situation and write and debug code. Your problem may be the most important in the world to you, but for other people there are hundreds of competing interests and demands. That should engender nothing but patience on your part, and a commitment to try harder to resolve your own problem and to share your eventual success. This is a sermon, but not a religious message! ___ helps those who help themselves.
Now, you said the quality of TI DAC (the TLV5618) is lower than the quality of the ADC (TLC4325), because it requires a 2 volt reference, because TI told you not to use a voltage divider to get the two volts, and because the two chips you have malfunction differently in your circuit. None of those are evidence that the quality of the chips are lower or that they cannot work with the Stamp. It is more evidence that you have a wiring error in your circuit, and that you need to study more how to read a data sheet.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tracy Allen
www.emesystems.com
Without looking at the spec sheets (you haven't earned my time to look at them yet) two voltage references are for one of two reasons, either: A) there are at least two channels so that you can individual set the dynamic range for each block, or
If instead of approaching things with a closed and critical mind you instead approach things in an open state of mind with the mindset of learning why the chip operates that way, you will come away with a better understanding, and actually feel good for learning something new.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·1+1=10
My advice to Bean is my best advice to everyone on earth -- if you don't agree now, you probably will within less than 3 decades. Try it, you'll like it.
As for the voltage references, I appreciate the explination because I learned something new -- but stand by my analysis on the basis of user-friendliness. I am waiting for the Max chips and continuing to explore Orion's advice.
As for those who think I have a wiring error, I can post a photo of my prototype board if you want to compare it to my circuit diagram and a photo of the TI data sheet pinout. Considering the Stamp works based on the debug window and only 3 wires go from the Stamp to the D/A chip which has only 8 pins total, and the chip works on one of its two channels, it's highly unlikely to be a wiring error. Let me know if that's what you want, otherwise, I'll pause until the Max chips arrive or Orion's advice yeilds fruit.
As far as "letting off steam" I think many have -- in one way or another -- made it clear that we're [noparse][[/noparse]Parallax] here to assist; but that doesn't mean that we'll have a canned solution for every single problem, and a polite request for assistance will get you as much help as you'll ever need (from many forum members). Your pot-shot approach to asking for help doesn't work for anyone and I think that has shown to be true by the responses in this thread -- most deal with your attitude toward Parallax and not the problem at hand.
And for what it's worth, we routinely work with 12-bit A/D and D/A devices; two that I've used in projects are the LTC1298 and LTC1257. Finally, the reason we have so many materials for the hobbyist world is that they tend to require more hand-holding than professionals.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax
Also high resolution DACs and ADCs will not give you the full precision when used in the breadboard, this is because they are both analog and digital on the same chip, which don't like to play nicely with one another. For more detail on this look at the reference sheet, there should be a section on proper isolation of the analog and digital ground planes, something which can only be accomplished properly on a PCBoard.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·1+1=10
Post Edited (Paul Baker) : 10/13/2005 7:53:22 PM GMT
Paul, Thanks I appreciate the hidden wiring defect tips. At present I'm not trying to use both DACs and ADCs on the same board. At present I'm only using the newest Stamp BS2PX and the TLV5618 DAC -- no other parts -- based on Tracy's trouble shooting advice. The DAC just doesn't want to cooperate. I'll try changing the wires, chip, and location plus VOM the wires to see if that helps.
But I agree that you should use a chip that Parallax has already worked with, because you'll be tapping into a knowledge database you will find through time that the employee's of Parallax will be happy to share with you (if you ask nicely).
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·1+1=10
You might want to learn how to use the proper tools before flaming the guys at Parallax. Time after time they've helped me.
Observe this link:
Google Link
697 hits from ONLY Parallax.com with the search term, "industrial". I would think they offer a large amount of information in the industrial applications. Not to mention the fact that they have several Nuts and Volts columns using 12 bit DAC's.
I took all of the N&V's columns and combined them into ONE single PDF, then when I want to work with a particular chip, I'll search this large N&V's file for that particular chip. Parallax is generous in the fact that all of the N&V's columns are decent PDF's, and not just image scans, this allows you to do a text search of the columns.
Last but not least, if you don't like the support that Parallax offers, then go to the standard pic and skip the pBasic! Call up Microchip and get them to help you out with your problem. Fact is they won't give you the time of day.
Knight.
I was following this thread and was wondering if this is an issue I ran into the other day. I'm using the Parallax RFID reader and an 831 ADC (for an analog IR sensor) on the same circuit and they do not play nicely together. I had to shut down the ADC power with a BS2 pin when I read the RFID or I would get nothing. Is this related to "ground bounce"
Jason
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·
Steve
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
·· This is off-topic, you should start your own thread for this issue.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com