RoadTest: TI LDC1000 Evaluation Module
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?: None
What were the biggest problems encountered?: Rushing in.
When the LDC1000 Evaluation kit arrived I found a large box containing athe LDC1000 Module and a really usefull Angular, Lateral, and Axial positioning test platform. There was also a smaller box containing a second module. The kit supplied is an almost complete package for evaluating the LDC1000 inductance to digital converter. I say almost, because to make proper use of the kit a USB extension lead is required, which I didn't have lying around. So once a cable was found I set about having a play.
The package says, connect the board, register at ti.com and explore. So I connected. It was detected and asked the usual search for drivers dialogue. I did this... Which failed. So next to TI's website, downloaded the software and installed. I should point out that I've installed it on both windows XP and 7, both with administrator rights.
Installation was easy but did throw up a compatability error, I clicked continue and it carried on installing.
On installation finish the evaluation software opened but no connection. A quick unplug and plug back in of the module had it connect automatically and I was away.
First off I popped the module into the test platform and played with the various position sensors and then tried looking at what effect all my loose change had on the two graphs, proximity data and inductance, I was presented with. I have to say this was kind of fun. In less than 10 minutes I could actually see lines wiggling on the screen in a controlled manner. I then tried to play with the settings in the program and got a bit stuck... It turns out that to edit some of the settings you need to stop the data updates first. Had I also downloaded the user guide and or quick start I would have known this but... The GUI is well written and it has tooltips in the bottom left corner. Look out for these as it does help as a lot of the features are hidden. For instance you can right click on the graphs to save CSV Data (Note the .CSV is not automatically added to the file name) or set the scale of the graphs. In the configuration page there are a lot of settings to play with and get quite confused about, and here is my only gripe with the software. I would of liked to get some help when I clicked on help. Just to have had the user guide, and quick start PDF's linked in the help page would have been good. I would be happy to have a slightly larger installer if it brought in the documentation automatically.
Anyway on to some testing. I wanted to try the modules because I'm involved in product sensing, and interactivity. so essentially I want to be able to detect something is there, either mechanically (Switch), optically, capacitivley or now inductively. (Is that a word?) Interestingly a lot of the products we tested we could detect something. Generally because most things have a bit of metal in them, however as long as a material has some inductance it will cause a change. For instance, not only could I detect my bottle of pop, but I could also detect if I was holding it. Generally for this effect I needed the coil to be touching the product. Not all products will work in this way because they can't be detected using inductance, and some products such as bottles have voids in the base which would also prevent detection, however with a different coil design this could be improved.
Which brings me neatly on to my next comment. The TI website has some good design tools including a web bench tool to assist with coil design and a video showing how easy it is to change a coil. This will be my next stage and when I've got some usefull results I'll add them on here.
Further work and conclusion. As a result of my tests I've been able to detect a customer holding and picking up products. This is useful to be able to initiate a media presentation, or simply count product interactions to guage interest in a product. I'd be interested to find out wheter it would be possible to multiplex coils so I could easily destinguish between several products and reduce the cost of having an IC for each position. Alternativley it may be possible to use a large coil and tag the products with metallic paint or labels in such a way that each product is uniquely identifiable by interpreting the readings. There is a lot of information on multiplexing and on all aspects of use at the TI Inductive sensing forum http://e2e.ti.com/support/data_converters/inductive-sensing/f/938.aspx. One issue I will have is trying to explain why it won't work on everything the sales guys try to put on the coil when I demonstrate what can be acheived.
P.S. I noticed in the manual you can run two boards and two GUIs at once. This does work, however when the boards were enumerated they were assigned com ports (9 and 10 on my laptop.)
The boards must be connected in sequence, 9 first then 10 and the GUIs have to be running first. If i plug them in together or start the GUIs afterwards it always detects 10 first then ignores 9. I have marked the boards and just unplug 10, let 9 detect then re-connect 10.