ShaunR

QUOTE (n00bzor @ May 24 2009, 11:57 AM) Obviously "operator error" then

QUOTE (n00bzor @ May 24 2009, 08:40 AM) 0.12 is still far too low. It equates to about 41mA (V=IR). Try a 1K5. Then measure the voltage across the digital output to ground. If its at 5V (or very close) then that isn't the problem. Many output sources (digital/analogue outputs, power supplies etc) have a system of protecting the circuitry from short circuits (a fuse for example). The term "crowbar" in protection circuits is analogous to "being hit over the head with a crowbar" i.e instantly halting the cause of the problem to protect the curcuitry.

According to the specs. The U6009 is digital rated at 5mA and according to the current transfer characteristic of the 4N25, it should work down to about 0.5 mA (although you wouldn't get much out of it). It may be that the digital output is detecting the LED as a short (don't know if it has a crowbar or not...but might). Try putting a 1K5 in the digital line to fix the current to about 3.3 mA and see if that works.

QUOTE (Vladimir Drzik @ May 21 2009, 04:25 PM) Sorry. I misunderstood. The only thing I think your missing is that VBuilde/VAssistant doesn't actually have the Labview environment embedded. It is a pictorial representation of the functional blocks with its own editors ,and, when you execute the code, it interfaces directly the the NI vision dlls. The only time that Labview is used is when you want to create the vis. Then Labview is launched and the vi's are generated (probably using scripting).

QUOTE (Gary Rubin @ May 23 2009, 12:46 AM) Indeed. But you can use can set the output to trigger off of an input and gate that input (just wire it to the other output). I think the "Pause" just pauses the generation from the software making it difficult to synchronize continuous pulse trains. Whereas Gating is done at the hardware level.

Best advice I can give. When you find a good AE, get his/her direct line number and put it in your contacts list. I've been using the same guy for the last 3 years and you don't have to spend 15 mins going through all the secretarial rubbish to get to talk to someone QUOTE (Gary Rubin @ May 22 2009, 03:27 PM) I think what you are after is the Counter Gate. (CTR n GATE) It enables you to Start/Stop/Mask counters (if configured). You have to sacrifice a PFI, but if I remember correctly, the 660X series have loads of them anyway.

QUOTE (angel_22 @ May 22 2009, 02:51 AM) Sorry. I don't have DSC installed and I havn't used it for a quite a while. Someone else will have to help you with this. QUOTE (jcarmody @ May 22 2009, 07:56 PM) This reminds me of my Senior year in High School when my Electronics lab partner told me to "hurry up and fix it, I want to get this done." lol. He was obviously a manager in the making

1. Is the PIC on an evaluation board or have you built the board yourself? (I hope its the former!!!!) 2. Has your PIC got software in it? (You have to program a PIC to use its USART and there are plenty of examples of this on the net) 3. If you are using an evaluation board, have you successfully downloaded a program/example with the tools that came with the board.? If you are at No.3 then (and only then) you can start thinking about Labview. You will then be able to use VISA to open the Com port and write/read the command strings/data using the settings from the example and you should be good to go.

You can also write headers and footers in one hit.

QUOTE (rahul @ May 21 2009, 05:56 AM) We had a lot of problems with firewire (including what you are seeing as well as cards not allowing windows to boot and having to use a hack to get more than 100Mb/s which only worked sometimes between boots). So much so that we now use GigE (much better) It's only some windows installations that are problematic and (I'm afraid) we did not find any solutions.

I've got one of these that I wrote before we had the spreadsheet vi's. You don't need that many. Just pre-process with a for loop (to give the page and you can check the dimensions to bypass) and use the build array just before you save to to append/prepend a header and footer (your description can be part of the header or footer or you can have a separate one). Then just wrap that as a poly vi for your different types. You can also do things like checking that the file exists and only writing the header if its a new one and appending instead of overwriting so you can use it as a logger (don't forget an override switch though . I actually prefer to save different "pages" to separate files as you can load each one up as a separate sheet and it makes graphing and things easier.

Subpanels. Example in the usual place.

QUOTE (SLearner85 @ May 20 2009, 05:52 AM) No...... But your hard disk can. There is an "examples" directory and if you have vision installed there will be examples in there.

QUOTE (angel_22 @ May 19 2009, 07:51 PM) \LabVIEW 8.6\examples\general\templates\Dialog using events\Login Dialog.llb

QUOTE (angel_22 @ May 19 2009, 02:46 PM) lol.Some of us have to work for a living! As Asbo said. there's an example. Your UI is comming along nicely. You obviously have an artistic flair which I severely lack. Is this software actually going to control anything? Or is it a proof of concept?

QUOTE (Gavin Burnell @ May 19 2009, 04:57 PM) This is exactly what I was trying (rather failing) to describe on the "Exterfaces" thread.

You could do all that, but it might be easier to use use the "Overlay" functions in the "Vision Utilities" library.

QUOTE (keat007 @ May 18 2009, 01:14 AM) Indeed. The USART is just a communications interface to the microcontroller to talk to other devices like a bluetooth or PC. Nearly all modern microcontrollers come with at least 1 (usually used for programming it) and many come with 2 or 3. With a USART (which has digital voltage levels) , you can wire directly to other comms chips to provide your microcontroller with virtually nay interface you desire (bluetooth, USB, RS485, RS232, WIFI etc). The "Stamp" is just another flavour of microcontroller (from what I can tell) like a PIC or ARM. The only problem with the Stamp is it only has digital IO and you need to measure an analogue signal. You can (as you pointed out) add additional hardware to convert the analogue signal into a digital one, but I see that as doing it the hard way As my Toothpic is on its way I decided to look at the software for programming it. You can download a free toolset but I think what will be of more interest to you is that they have existing firmware for acquisition. I think if your looking to get up and running quickly and not too bothered if you use Labview or not, then it might be worth reading this. Looks like the server is in the bluetooth device (ike a webserver) so data can be viewed on anything from a PC to a mobile phone. http://www.flexipanel.com/Docs/DARC-II%20DS382.pdf' rel='nofollow' target="_blank">DARC II Oh. they ship to Singapore from that link I gave you

QUOTE (Tubi @ May 17 2009, 10:25 PM) This time, it's because you don't have enough samples to begin with to do the measurement. When you run at 20Hz, you generate enough data for about 2 cycles. With the limits set tightly, this is just enough threshold transitions to do the measurement. At 3Hz you are only generating about 1/4 cycle to begin with. So no matter what you set the thresholds to be, you will never have enough transitions to make the analysis. I have adjusted your signals to give enough data for the measurement @ 3Hz. See attached. http://lavag.org/old_files/post-15232-1242599891.vi'>Download File:post-15232-1242599891.vi

QUOTE (keat007 @ May 17 2009, 02:25 PM) There are examples of acquiring via bluetooth in the Labview examples.

Just hunting around on google (wonderful tool) and found this. Tooth PIC It would be ideal for your app and cheaper than bolting together all the different components your intending to use. You only have a short time to develop. So I would suggest not faffing around trying to get different modules to work together and go for a one-box solution.

QUOTE (keat007 @ May 17 2009, 06:14 AM) Not quite sure what your asking here. You need to get your voltage measurement into a form that can be output to your bluetooth module.. For that you will need an analogue input of some description and an interface to your bluetooth module - A U(S)ART. I've just been looking up the "StampII" and it seems it doesn't have an analogue input. It seems that these "Stamps" have a UART already so you can connect it to your bluetooth directly anyway. (people seem to be using them a lot for Boebots and controlling them using PDA's etc). But I'm afraid, if it doesn't have an analogue input, you cannot measure a voltage (easily). You can have an RC circuit and measure pules to try and make a rudimentry A2D converter, but I wouldn't recommend it for a medical application. So your issue doesn't seem to be Labview. Its that your hardware can't measure voltage. This is what others say about measuring voltages with a "Stamp" and they basically say that you need something else (like a PIC). http://www.zonerocket.com/Voltage-checker-for-Basic-Stamp-II-robot-project-article5144--2.htm' rel='nofollow' target="_blank">Voltage Checker For Basic Stamp

It's very easy to use bluetooth with Labview. There are a few examples in the examples directory. I would suggest a PIC to aquire the data and interface via its UART to your Bluetooth transmitter and you can use Labview to receive and chart/graph/analyse the data on a PC with your dongle.. A PIC is small, and cheap but requires C knowledge (probably cost you about £5-£10 to build) but have UARTS, and several analogue and digital inputs - more than enough for your task. It would also be very portable and could be battery powered (matchbox size?). If you go for labview for the acquisition then you will require another PC to run the labview run-time with some sort of compatible acquisition device, or something like cRIO, fieldpoint etc which can run labview (which are really overkill and expensive).

QUOTE (crelf @ May 16 2009, 07:16 PM) I don't see them in the main top level pallets either . But if you access them through the 7.x, they are in the main pallets there.

Another method which is very effective is to look at a line of pixels (line profile) and look at the rate of change at edges. If you are in-focus and looking at series of lines and spaces you will get sharp peaks which become much flatter and rounded as you go out of focus. A simple d/dx will give you the rate of change.