Quad-Channel, Analog Output Module - Review

Table of contents

RoadTest: Quad-Channel, Analog Output Module

Author: DAB

Creation date:

Evaluation Type: Evaluation Boards

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?: NA

What were the biggest problems encountered?: Try as I might, I could not find a way to make the board work. A Real bummer!

Detailed Review:

First I would like to thank Element 14 and Texas Instruments for selecting me for this road test.

 

I knew this board was an engineering evaluation device, but little did I realize that this road test would become a design challenge.

 

That said, I hope the other testers have better luck with their boards than I did.

 

The first problem I ran into was when I did inventory of the components.

The board was supposed to come with a USB extender cable, an interface device and the evaluation board.

Here is what I received.

image

The first thing I realized was that there was no way to connect the USB 1.0 cable to the TI interface device.

 

I contacted Randall and he contacted TI, who were unconvinced that I had received the wrong cable.

 

So rather than enter into a urinal Olympics, my wife and I searched our copious cable collection and found the right cable.

image

So if anyone reading this post can figure out a way to connect the cable provided to the interface device, please comment below.  I would hate to think I missed something obvious here.

 

You can now see how to properly connect the USB cable to the interface.

image

Next I looked for the demo software on the TI site.  It took a considerable time before I finally found an "old" demo software package for the chip, but it was for an earlier version of the Quad DAC board, so I installed it in hopes that it would be sufficient to run the board.

I set up an external power source with my trusty Pico-scope and multimeter to begin testing.

image

Then I fired up the demo software and it booted to the following test screen.

image

As you can see, there are a lot of options on the GUI, but then I noticed that there was no Help file, nor could I find a users guide.

I did finally find a very terse write up in the interface guide, but I discovered that TI had recently upgraded the interface unit from an 8051 based device to an MSP430 based device.

So I was not sure if this set up would work.

With everything connected, the interface unit gave me two green lights.  The first indicated that power was available for the interface and the second was supposed to indicate that communications with the Quad DAC board was functioning correctly.

 

So I started probing the outputs to see if there was any voltage.

Hmmm, nothing.

I re-read the short guide and saw that if you entered a value in the GUI, it would immediately show up on the output.

So I put in a 4FFFF code, which should have provided the midpoint of my 0 to 12v DC input source.

Again, nothing.

I tried the sweep range, just in case 4FFF was midrange zero volts.

Again nothing.

So I began a systematic adjustment of all the values and buttons to see if I could get any output.

 

NADA!

 

I hated to give up on the board, but there are no test points, other than the input and output connectors.

The I2C control is on a very small connector and I did not have any clips that would fit on the connector without shorting it out, so I could not verify that the interface board was correctly controlling the DAC chip.

So very reluctantly, I decided it was time to stop.

 

On the plus side, the board is very well made and I really liked the addition of the little plastic feet on the board to keep the bottom traces clear of any short hazard.

 

On the down side, well, try as I might, I could not make the board do anything.

I was quite disappointed as I have used TI boards for over forty years and have always found their support excellent.

I hope this test is an anomaly and not an indication that TI quality might be falling.

 

I will make one caveat.  I am suffering from a form of ADD and I entered this test to see if my condition had abated with new medication.

Good news is that it was better, but evidently I have not improved enough to decipher how to make this board work.

 

If any of the other testers have better luck and can provide me with some hints, I will revisit the board and update this review.

 

I had hopped to use this board for some upcoming research experiments I have planned, but for now, I will have to look other places for the tools I need.

 

Thank you for reading,

 

DAB

Anonymous
  • if I drop one I never find it again.

    What do you mean drop one, I can't see them to drop them in the first place ... image

  • I know what you mean - with the small SMD resistors now, if I drop one I never find it again.

     

    All the roadtesters are going to run into the same problem with the demo software, so hopefully someone will puzzle it out (or TI will sort it) and you'll then be able to have another go with the board.

  • Hi Mark,

     

    I tried all the combinations of buttons and data I could think of.

    That does not mean I did not miss one, but I tried to go over this thing as best I could.

     

    Yes, I did find that older manual, but as I said, that SMU device was an 8051 controlled processor.

    The new one is MSP430 controlled and I am not sure that they are plug and play replaceable.

     

    I have not given up, I have moved on to the PIR sensor road test, which unfortunately also requires some design effort to get working.

     

    Have no fear, I will keep plugging away, but I really do want to see what the other road testers ran into.

    If it is just me, I can accept that, like I said, this was a test.  Maybe it is time for this road tester to ride off into the sunset.

     

    DAB

  • Hi Jon,

     

    I though of that, but my eyesight isn't what it used to be.

    Even with my magnifying lenses, these new fangled connectors are damn small.

     

    DAB

  • Oops that makes it hard then.

  • mcb1 wrote:

     

    ...

    Jan may be able to duplicate it and verify if there is an issue.

    ...

    I don't have the board under test here. I have a home-brewn DAC and ADC board that's I2C controlled for Don if he can use it for his experiments.

  • Don It is sad that there is no obvious support for this, but I did see this note in the RT page.

    This product is a specially built reference design for this RoadTest that is not available for purchase. Hence is a unique opportunity to review.

     

    It would appear that there are some links that look like normal text and one of them took me to this page.

    http://www.ti.com/lit/ug/sbau248/sbau248.pdf

    The hardware looks different, but it does use the same chip and it seems some of the descriptions match the GUI picture.

     

     

     

    On page 9 it clearly shows the cable required, so maybe someone needs to order TI some new glasses.

    image

     

     

     

    Looking at the GUI picture you posted, there was one selection box that you might have overlooked (or maybe you tried it)

    image

    It does read that "once enabled" you can enter values, and a reasonable person might expect that unless the output is enabled it would refuse entry, BUT I've seen all sorts of software and sometimes it represents what you expect, and other times .....

     

    Perhaps if you have time you could try it again and grab a snapshot of the GUI with settings that you believe should work.

    Jan may be able to duplicate it and verify if there is an issue.

     

     

    Hopefully someone in TI takes note and makes contact.

    I was very impressed by Infineon and their response to the Motor control issue one tester found.

    Their example of support needs to be emulated by quite a few others.

     

    Mark

  • I hated to give up on the board, but there are no test points, other than the input and output connectors.

    If I was faced with this, I'd solder some wires to the connector pins and probe those. Use solid core wire-wrap 'mod' wire as it's much easier to solder to small pads without the strands shorting to the adjacent pads. Helpful hint: don't make the wires all the same length - if you do, at some point the probe tips will touch together and short signals.

     

    Alternatively, create your own test points on the board. Scrape away the resist from a track and solder a loop of wire to it.

     

    The datasheet says the interface is 4-wire SPI. It will probably be enough for you to look at just the clock and the data going to the board, but you'll get very confused if you try and interpret it as I2C.

     

    What did TI say when you queried them about the demo software? Did they decline to help you?

     

    If they're not prepared to support you using that, you should be able to get the converter going by driving it from practically any SBC with SPI - choose whichever you're most familiar with to make the programming easy (PSoC maybe?).

    It would be a shame not to finish the roadtest - it's a nice chip you're evaluating with the board and TI have gone to a lot of effort to put this board together.

  • Hi Jan,

     

    Thanks for the offer.

     

    I will keep it in mind as the experiments get better defined.

    My coauthor is currently reviewing my idea to give it the "giggle" test.

    If he agrees with my ideas, then we will work out the details for testing.

     

    If successful, the experiment will prove a great deal about my theory on photons and prove that they have both mass and charge.

     

    At that point, the whole atom model we developed is pretty much a given as the photon is the basic component for how atoms work in physics, chemistry and biology.

     

    More later.

     

    DAB

  • Hi Monte,

     

    Yes, I am trying to get back into things, but it is still a struggle.

     

    Given that the humidity here is about 80%, I don't think a static control mat would help much.

     

    I do try to take reasonable precautions, but I have been know to kill electronic devices with my normal static charge.

     

    DAB