GSR

Dear all, I need to build a stepper motor control using MC3479 stepper motor driver. However, I don't know much about stepper motor and the stepper motor driver. I am not sure whether MC3479 is a standard stepper motor driver, but I hope my question are simple for everyone. If I tell the stepper motor to position A, do I need to keep the current even to keep the motor at that position? Or it will lock in that position? <===== the smiling face that I like the most If the load is too heavy and the motor cannot reach position A with one clk pulse to the stepper motor driver, what will happen? If I want to ask the motor to stay in a position, should I send a logic 0 to clk pulse?

The noise itself like a lot of spikes + sine wave. I connected an oscilloscope near the treadmill; and moved the probe from close to the treadmill to far away from treadmill (No one is on treadmill, but the treadmill is rolling at 3 mph). The noise goes down. This mislead me that the noise must not relate to powerline I think you give me a good hint which the noise can also come from powerline for the constant speed control. May I know how to resolve two signals? (They are in the same frequency band)

Dear all, I need to record subject's neuromusclar activity (by surface electrodes) during he is walking on a TREADMILL. The treadmill create 180mv pk-pk noise; and the muscle activity is ~60uV. After the noise + signal passing through pre-amp, and 2nd order bandpass filters, the noise signal is dominant . Any idea how to overcome the problem??? I did try to put a little metal shield which is ground on the electrodes, but it did not help

Just started to work in a new location 2 months ago; and met a guy from another team a month ago. Talked to him for 5 mins the 1st time. In the following week, he looked for me everyday to help him get into our building. I understood he did not have the latest key card, so I helped him for a week In the last 3 weeks, he almost came to my office everyday, and talked about stupid thing. Even me and my teammate were talking something important, we would just come and join. I was starting unhappy with this type of behavior. In the last weekend, I was building a circuit in my office. He came again, I told him that " I am sorry I am very busy today and have not time to talk to you, how if we talk in the other day? " He said ok and left. 5 mins later, he came back, and told me " your boss is here today at his office" I was very unhappy and asked "what did you say?" And he know he should let me alone, so he said not to bother me. Today, we met each other face to face, I thought we would say Hi at least. But he did not even look at me. I felt bad, I felt I did something wrong. Have you ever met anyone like this?? What will you do?

To be hornest, they make me feel very unhappy. Should I just contact the sale support and ask for their sale manager to reply? I really want to get something back from Mathworks:shifty:. Our lab spends money to buy many toolboxes from them, but they mess-up our stuff:(. Do you think I can ask for free online training:lol:? I want to learn stateflow:D or even more. Or I want to get so-called the icon of Matlab hero, the matlab t-shirts for everyone in my lab:D.

But I could not find any number or email address that can be used for complaints I am so unhappy that I need to submit a paper by the end of this month. Yes this month Aug31, 2009. However, I still have not gotten their toolboxes .

I submit a order, the mathworks sale representative (Mrs. R) is having 4 month vacation. She asks our purchase department to contact another mathworks sale representative ("Mr. T"), who was also out of office for ~ a month. I called mathworks hotline, they ask me to send the purchase order to info@mathworks.com. My purchase department did that, but did not get any feedback. Two to three weeks later, I was finally able to contact Mr.T, he said he needed my purchase department to send him another PO because he won't get the email from info@mathworks.com and he had never received any PO form my purchase department. OK! My purchase department send the PO to Mr T; and I received the notice from my purchase department. At the same time, I also forwarded the notice to Mr. T. I called Mr. T. :wacko:Three days later, he said he did not receive anything again. I told him I forwarded the notice to him; and he found from his email box and figure out I did email him the notice:angry:.Mr T is a axx-hole and ignored all my purchase department and my email:frusty:.He told me that the quote was expired, but he would still try to submit the order. (But who make the 1 month quote expired????? ) I really want to contact his head to complaint the issue. Who should I contact to? Any email address or phone number??

Please ignore, find solution. Thanks for reading this topic

Dear all, I use simple opamp a lot. Recently. I use an AD620 biomedical bipolar opamp as a preamp for EMG circuit. I found out that there is a reference connection, what is the reason for a bipolar amplifier having a reference connection??? Could you please give me some idea?

If I have an equation y(t) = a1x1(t) +....+a9x9(t)+nonlinear factor+noise want to do linear regression any different between sample rate is 100Hz and 1000Hz? Assume 100>>nyquist frequency Will the fitting be better at 100Hz because of the variable to sample rate ratio is higher at 100Hz?? BTW, what is this icon mean:ph34r: <========????

May I know what is the benefit to become alliance member??

{signal - mean(signal) }/std(signal) ??? I am not sure the name , I think it is used in Z stat or F stat.

Zero control error

Dear all, This question may not related to LabVIEW, but I think I can ask here because the LAVA lounge should allow to talk anything . I am doing a Simulink control system project (See pic). A and B are the input, C is the recorded output data. If the model is prefect, the scope should give a zero reading. I have 6 parameters that I need to tune. I can use my knowledge of the system to have initial values, but 6 parameters tuning is too difficult for a new babie . Does any function in Simulink, Matlab or LabVIEW handle this type of problem?? Thanks

Thanks for your suggestion However, on the other hand, do you think this prevent bending feature affect the reading??

My situation is having 500lb load cell to measure the force that in between 0 - 250lb. I understand what you say. Your idea is like the potential divider in Electrical term. I really have no clue why my boss and his friends consider that is right . The biggest problem is the compression and tension forces have different offsets and gain value because of the "Middle sturture" bypass part of those forces. Moreover, how tight the screws will also change the gain of the reading and the "Middle sturture" also creates an idle region. My understand is that the output is Y = G1*compress if compress > theshold1 and Y = G2*tension if tension < thershold2. Those thersholds can be changed by turning those screws.

I agree with what you said . Exactly what I am thinking, the load cell is not connected independently to those two metal pieces because of the inter-connection of those screw and silver disk The biggest problem is that I am not the designer and I don't have the CAD drawing. I should not be lazy and I should use make a drawing using pencil BTW, I only understand English. Do you have English version of the above link? Thanks

Dear all, I need some suggestions of this mechanical design (I understand it is not related to LabVIEW , but this is the last step before LabVIEW, please help ). I think there are some problems. The idea is to use load cell to measure the tension and compression force across two metal structures. The load cell gives a linear reading for compression and tension, the structure in between should not affect the reading The support frame is designed to prevent twisted force act on the load cell One of the load cell hole is a tap hole, the other one is a REGULAR hole Please give some ideas, do you think the structure in between does not affect the reading??

Dear all, Could someone please share the experience? I have submit more than 1000, and I only get one face to face interview. On the other hand, If you are a boss, how would you think of a person study for long time and without industrial experience? Moreover, how would you think about a person only have a temporary status to work even if he claims that he does not need sponsorship and will get green card ? Thanks

QUOTE (Dan DeFriese @ Mar 18 2009, 11:45 AM) Thanks QUOTE (Louis Manfredi @ Mar 17 2009, 09:30 PM) Hi Zmarcoz: I was in a similar position to you a few years back. A few points to make: First, in (partial) answer to your specific question, a few years back I taught myself basics of C++ using Metrowerks Codewarrior U. No particular certification, but it was free web-based learning, I learned a lot, I recall even the compiler was near free. So a good place to start, first learn the stuff, then worry about the certification. From what I understand Metrowerks is sort of a thing of the past, but their parent company Freescale, still sells some of their stuff & perhaps runs the Codewarrior U. Little enough difference, I think between one flavor of C++ and another-- at least at the entry level. Second, as it turned out for me everything I did to reinvent myself made little difference in the long run.-- Getting my (no longer current) CLD certification, learning a little C++, etc. didn't really end up making that much difference for me in my search for gainful employment. Got a few consulting gigs through the CLD, was happy to be able say I wasn't totally ignorant of C, even though I never got a job as a result. The LabVIEW was almost always helpful not on its own, but as a compliment to my broad experience in the wind industry. None of the programming skills had that much to do with my ultimate return to steady employment. As it turned out, what did it for me was my skill and experience in my old industry, and friends and contacts in that industry. So here I am, working for someone I went to school with 35 years ago, working in a field I've been in off & on for 35 years. I've written maybe a few hundred lines of C or C++ code in the line of duty over those years (far less than I've written to teach myself the languages). Currently I still do some LabVIEW programming, maybe 5% of my time, but for me its just a tool, not an ends unto itself. So, maybe for you the best thing to do is to focus on the field where you have your degrees & where you've spent the most time, make sure your colleagues in that field know you've got programming skills in LabVIEW that might give you and edge, might help you to be more useful in that field. Third-- An on this point I'm most certain! Don't get panicky or down on yourself during the job hunt. Its a down economy. Its not your fault if you don't find a job, unless you give up looking. You might have to chase 20 leads (or more) to get an interview, might have to go on a half dozen inteviews (or more) to get an offer. Best to be chasing several leads at once, that way the ones that don't pan out don't hurt as much if there's other ones that still might work. I'd pretty much gone into zombie mode, putting in applications without much hope, and out of the blue my old college pal calls to see if I'm available to consult, which eventually grew into a full-time permanent position. Keep an upbeat outlook & present an upbeat public image-- including in public forums like LAVA-- (even if upbeat is not totally real) and things will work out eventually. Best Regards, Louis Really thanks so much that you are willing to type so long to tell me so much information and suggestion :worship:

QUOTE (Cat @ Mar 17 2009, 06:18 PM) I say (gooey) to indicate the user interface for the last 3 years :laugh: QUOTE (Gary Rubin @ Mar 17 2009, 06:51 PM) Speaking as a non-software engineer, my feeling is that Software Engineering is a discipline, just like mechanical or electrical engineering. It shouldn't be confused with software development, any more than a carpenter should be confused with an architect, or an electrician confused with an EE. As EEs, physicists, MEs, or whatever else most of the people on this board are, we all have lots of experience doing software development. We might even be really good at coding, algorithm development and implementation, etc., but that doesn't make us qualified to act as a Software Engineer. Right! I don't understand what the company is because only an agent talk to me. He just told me there is a position and ask me to finish the exercise. Anyway, I start to find out whether Microsoft offers any C++ certification exam. (I am a lazy person, so I need an exam to force myself to learn)

Dear all, I understand this is not relate to LabVIEW, but relate to me (a LabVIEWer). Is there any C++ certification by Microsoft? Thanks

QUOTE (Cat @ Mar 17 2009, 01:05 PM) Thanks for your suggestion I just start with a bad luck day. I received an email about a software engineer position an hour ago, they send me an exercise and need me to finish it. The exercise include a short Matlab, a short C programming problems and a long C++ problem. I spend 2 mins to solve the Matlab and C problems. However, I have never programming C++ in my life. I just feel myself a piece of shit. Why did I learn java not C++. I still try to solve it, but they are asking "automated unit tests" which I never never heard. OHHHHH, lost another chance to have a job. QUOTE (shoneill @ Mar 17 2009, 08:06 AM) I can't believe somebody can be used to programming LabVIEW and not know what a UI is. But perhaps English isn't your first language and it's called differently where you are so.... to find out what UI is, search for "UI" on wikipedia. To know more about noise reduction techniques, you kind of have to first know about the signals upon which the techniques should be used. Noise reduction in optical systems is different to digital systems is different to analog systems..... Shane. Thanks for reminding me. I thought GUI is the standard term . When I was living in foreign country, I wrote American addresses, I used "U.S.A." as the country. However, I found out that American wrote their country as "U.S." after I have been here for years. I used to use the Matlab version "UI" which is GUI, so I am sorry that I asked the stupid question. :laugh: Btw, how will you pronounce UI?? Do you just call it U-I or call the long form user interface?

First, Thanks for everyone to answer me the question As my first non-academic interview, I did a very poor preparation. I was asked to prepare a presentation 2 days before the interview; and I know the exact date for interview as the same time. Too many things need to be done before a few hours of driving to the interview. I had prepared the interview for a week, but I went to a wrong direction! Spend a few days for preparing the 200 standard questions: e.g. what is your weakness?? Spend a day to understand the company. However, I really misunderstood the position until I asked the manager a question during the interview: How would you describe a typical day in this position? I thought it was a R&D position in a team, but it is a one-man-team position including customer service. I was so stupid that I did not read the undergrad. book, refresh my old knowledge. I was so stupid that I did not ask about this question "What knowledge other than LV should you know if you are a LV programmer" in this forum Anyway, good experience! I know much more about the industrial interview BTW, could anyone please tell me more about What is UI? and anything about Noise reduction techniques? thanks :worship:

After I fail in my LV job interview, I really want to know what knowledge should a LV programmer should know? I understand that the answer may depend on the company, but any general knowledge that I should know? Maybe I should give an example, I would expect a webpage developer knows about Photoshop, Dreamwaver, php, frontpage, etc