NIR Scan

Hello Tom!

Please read my responses below your questions.

1. If you buy the NIR scan evaluation module, then I presume you could replicate the design/product i.e. you get the full schematics, but do you get the firmware (source) for the DLP4500NIR DMD, DLPC350 DMD controller, AM3358 processor and ADS1255 ADC?
   1. That is correct! All of the schematics and source code are freely available.
   2. http://www.ti.com/tool/TIDA-00155
2. Ideally our implementation would not be using a web browser but dedicated PC software, are there drivers or code examples for say VS C#?
   1. No, currently there are not any examples to interface with the NIRscan in such a fashion. However, the web interface actually controls the NIRscan through a separate command line application on the Sitara processor which could be controlled via external protocols. We currently documenting this command line interface for future release.
3. How much of the processing is done in the web browser i.e. is most of the processing done in firmware?
   1. The majority of processing takes place in the command line application mentioned in 2a on the Sitara processor.
4. I want a fairly similar set-up to the NIR scan, but I want to swap the light source and some of the optics. Would it make economic sense to buy the individual eval modules and program them up (assuming code is available question 1), or would it still be more economical to buy the NIR scan.
   1. It's hard to say which is more economical. By purchasing the NIRscan EVM you can immediately begin evaluating DLP technology for spectroscopy applications. While the source code is freely available for the NIRscan, it could take months to adjust it for different components.

Let me know if you have any more questions!

Best regards,

Blair 

Hi Blair,

Thank you for your answers.

1. What is the cost of any development tools/IDE's/compilers etc ... for any of the parts and/or processors?

2. Is it likely that this particular version will be superseded in the coming months? I have been an early adopter before (not withTI) and paid the price.

Thanks,

Tom

Hello Tom,

The DLP LightCrafter 4500 EVM featuring the DLP4500 DMD costs $1299, but it does not come with the DLP4500NIR DMD which you would most likely need for your spectroscopy application. The DLP4500 is designed for visible wavelengths (420-700nm), while the DLP4500NIR is designed for near IR (700-2500nm). The NIRscan comes with the DLP4500NIR DMD.

I do not know the cost or availability for NIRscan equivalent single element InGaAs detector board or thermal electric cooler board for the halogen lamp. The BeagleBone Black uses the Sitara processor and costs around $45.

You should not have any concerns about being an early adopter of the NIRscan and it is very unlikely a new version will be released in the near future.

Best regards,

Blair

Hi,

Thank you this is very helpful.

So there are no special compilers to buy to make any of this work? The reason I ask is that I bought what was a cheap TI sensortag board, but the development environment required to modify the firmware for the TI part (IAR workbench with 8051 compiler) was to cost around $3000, which came as a surprise and completely through our budget - which was a shame.

I am just checking there are no hidden surprises?

Thanks,

Tom

Hi Tom,

The Sitara processor runs TI's Linux distribution with the AM335x Sitara ARM SDK and the NIRscan software, but you should be able to use the standard compiler included with most Linux distributions to recompile the entire NIRscan application and Linux distribution. We have tested this process on Ubuntu. The NIRscan software download includes instructions on how to compile from source.

Best regards,

Blair

Tom,

Our firm worked with TI on the NIRscan design and production. Depending on what your want to modify in the optical assembly, we may be able to help you out either adapting the core NIRscan design or sub-components. You can PM on this forum or submit a contact form on our website and we can see what makes sense via e-mail.

Regards,

Adam Kunzman

Keynote Photonics

Hi Adam,

Thank you for the info. However, I want to have a "play" myself first, but we may need your services down the line.

Quick question. If we wanted to not work in the NIR region but more in the VIS region, then could we simply swap out the NIR DMD to the lower wavelength version without significant hardware/firmware changes? i.e. could we just drop it into the NIRscan EV?

Thanks,

Tom

Tom,

While you can change the DMD, you will also need to replace the grating most of the lens set - as the AR coatings fall-off rapidly under 1250 nm. We've looked at a special run of lenses but the costs are quite high for a small run. Also, if the grating blaze angle is different, then the light path geometry also changes requiring a new baseplate layout of the lens mounts. 

I hope this helps scope out your plans.

Hi Adam,

I don't want to hijack Tom's thread, but I have related question.

First, what is different in a digital micromirror device designed for VIS rather than IR? Is it just the coatings? I would like to project VIS+NIR with one of the DMDs, if possible.  But only out to around 950nm...virtually the center between the specs for the regular vs the NIR DMD.

Also, did you end up using standard off-the-shelf grating for this device? I have an old Oriel spectrometer that is extremely versatile due to the availability of multiple sized input slits, diffraction grating, and light source. At the same time, it is extremely slow to scan across a large spectra.

Thanks,

Aaron

Dear Aaron,

As you described, the fundamental difference in the NIR version of the DMD is the window AR coatings, which have been shifted to support wavelengths unto about 2500 nm. The transmission curve is found in the DLP 4500 data sheet, here.

The grating used in the NIRscan is a conventional ruled planar grating. It is not too difficult to replace the slit (though I have not done this personally). I believe the slit is 25 u in the NIRscan, a 50 u slit could easily be used without substantial change in the system resolution and gain in sensitivity - though there is more than ample power available in the standard transmissive illumination stage using a cuvette. Replacement of the grating is non-trivial as any blaze angle changes will have a ripple effect on the system calibration s/w and the geometry of where the slit is imaged relative to the grating. 

One of key benefits of the NIRscan technology is the scanning speed and repeatability due the the nature of the DMD. We can discuss further off-line on any specific needs you may have.