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There's been a bit of a hiatus from the spectrometer controller project as I've been busy with other things and was also on vacation with friends and family. There isn't much left to do.

No need. That answered my question. Thanks. I can either make the new PCB behave as in the manual, or like it actually is. Maybe I'll just store 32-bit floats.

Hi Chloderic, Whenever you get time, would you mind doing a coefficient query command (?C) on one of your units and post the result? I can't seem to set the coefficients on my stock unit. It accepts the command, but noting changes when I check the results. There are other things as well that...

That's great. Too bad I don't live near by. Isn't the 125 a soft seal laser?

Hi chloderic, I assume this reply was meant for the other thread. Yes, I'm aware of that. According to the manual 2048 pixels are transmitted from the serial port, and I'm getting 2049 in binary mode after decompression. It's not a big deal; the number of pixels transmitted can be made variable...

I've been quite busy but I found little more time to work on this project. I noticed that I'm consistently getting 2049 decompressed 16 bit words from the stock spectrometers rather than the 2048 stated in the command set manual. Can anyone confirm this? With my replacement PCB, then number of...

I remember programming in QB. Fun times.

Hi chloderic, I remember trying that command and it didn't seem to work on my stock spectrometer. I'll look into it. I could certainly add it to the new PCB.

Hi kecked, Thanks. I wrote a program in C that pipes data to gnuplot. Nothing fancy. I just execute the program in a terminal and a spectrum pops up in gnuplot. It also writes data to a file for manipulation in Octave. This is all in Linux.

Here are pixels 1 - 300 with dark frame subtraction. Reduced fixed pattern noise. Not seen are a couple of hot pixels between 300 and 2048 which are of course nulled by DFS. On the stock spectrometer, it appears that the optical black pixels are scanned, and as a result, several pixels are lost...

Nice setup. I may experiment with Raman spectroscopy in the future.

Hi chloderic, Thanks. Would you rather go by Bernd? I realize I should have used dark frame subtraction for the noise test. I'm mostly seeing pixel variation. In the future, I might install a peltier cooler to bring the dark current noise down.

Hi, I made an integrating sphere out of some cheap aluminum cake pans and a collimating lens from a bar code scanner. This definitely improved the results. Tweaking the bench and finding a better cable is the only way I'm going to further improve it at this point. Noise is about the same as the...

Hi all, The slits look ok. They might be slightly off. It's hard to tell. I think my makeshift diffuser isn't good enough and I'm getting a top hat to doughnut profile coming out of the fiber in some cases. A gaussian profile entering the slit would be ideal. An integrating sphere or cosine...

I've got six older Ocean Optics spectrometers and their spectral readouts definitely look much better. They have narrower slits as well. For what paid I for the B&Ws , I'm not disappointed, and I should be able to tweak them in, hopefully. They're fairly compact with my PCB.

I took the whole thing out and never bothered checking the orientation of the slit. The issues I'm having could also be due to a partially rotated slit. I also did everything with the spectrometer upside down to minimize dust contamination. Thanks. I'll have to check that when I get back to my...

Looks like I'll have to wait for that one to pop up or find something similar. The core on the stock Amphenol cable looks bigger than 400um. I bet the smaller opening on your cable helps too.

The spectral response of the CCD doesn't help either. I probably can calibrate it with my pyroelectric laser probe and a monochromator.

Hi Paul, Looks like I'll be poking around on eBay. I suppose I can measure the response of the cable by putting another of the same type in series after establishing a white light reference. Thanks.

Hi Chloderic, I did get the spectrometer to fail again. I gave it a few taps and it started working with no error codes. There must be a bad connection somewhere. I found some time to write more code and to some testing. Hopefully, I'll be able to release the project this month. The alignment...