Author Topic: Linear CCD, how to get it working?  (Read 27622 times)

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Offline DajgoroTopic starter

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Re: Linear CCD, how to get it working?
« Reply #25 on: December 18, 2013, 02:08:52 pm »
Belive it or not, it is again SH signal ! It is absolutlely clear from timing diagram and i have mentioned it already (not once). SH signal transfers charge from pixels to pipeline AND resets the pixels.
Ok, I got that part, so while sh is low, the charge is constantly being transferred?
So if I were to stop transferring the image half the way for a moment, I would get a second exposition?

You'll need faster clock to get usable results (usable integration times), and by faster I mean at least 20 times !
Actually, it suits for my project to have a long exposition time.

Good luck if you are still trying to use old crusty 8051 for it.
It is what I have in my drawer at the moment. :-/O
Actually it is a 8031 + external eeprom...  ;D

Stop whinning about datasheet, it is perfectly fine - all information needed is included. Yes, it is not a cookbook, but there is a reason why it is called datasheet, right ?
Comparing it against a datasheet of a mcu, or some other digital ic it is kinda short...

Good thing that we have the eevblog.  :D
 

Offline nes

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Re: Linear CCD, how to get it working?
« Reply #26 on: December 18, 2013, 02:51:30 pm »
Good luck and keep on persevering! I did not realize you were using such an ancient micro. (I think it will make your life much easier to switch to something with decent compiler support and a better selection of timer hardware though.)

Anyhow, I suggest black tape is probably not going to work. the package is glass and light will still get in from the sides. You need to get yourself a light-tight box of some sort while you are experimenting, even if you do manage to significantly reduce your integration time.

 

Offline DajgoroTopic starter

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Re: Linear CCD, how to get it working?
« Reply #27 on: December 18, 2013, 03:26:47 pm »
Good luck and keep on persevering! I did not realize you were using such an ancient micro. (I think it will make your life much easier to switch to something with decent compiler support and a better selection of timer hardware though.)
Actually that is another project. I build a small computer around the 8031 because it has that nice feature of having an external bus, so that I can nicely interface ram and peripherals.
For another project I used the atmega162 but its address space is completely messed up.
The only micro that I have that has 2k is the atmega32, but that leaves no room for program variables...

Btw, Keil uVision is a surprisingly good C compiler for the 8051, and I  had no issues running the code on the crusty old 8031 @16MHz.   :-/O


Anyhow, I suggest black tape is probably not going to work. the package is glass and light will still get in from the sides. You need to get yourself a light-tight box of some sort while you are experimenting, even if you do manage to significantly reduce your integration time.
I won't be using black tape at the end of the project. I do have in plan to build a nice chassis which would place the ccd in complete dark, only allowing the wanted light on the sensor.
 

Offline kony

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Re: Linear CCD, how to get it working?
« Reply #28 on: December 18, 2013, 07:06:16 pm »

Ok, I got that part, so while sh is low, the charge is constantly being transferred?
So if I were to stop transferring the image half the way for a moment, I would get a second exposition?

Actually, it suits for my project to have a long exposition time.


Would you please just study the datasheet page by page, slowly. Please!

While SH is low, sensor is integrating charge, on rising edge, charge from pixels is transfered to pipeline, on falling edge pixels are charged and disconected from pipeline. Pipeline and pixels are not the same thing ! You are reading data from pipeline (analog shift register), not dirrectly from pixels and there is no way you can read directly from pixels. Charge is being integrated on pixels when shutter is low no matter if you are reading data out or not. And you must have BT and RS signals still running - STILL !

State where SH signal is high more than just few microsecs is not mentioned nowhere and hence I strongly reccomend you to keep it this way !
Also, you MUST read whole video frame including last invalid pixels. MUST ! Some sensors even might stop to operate properly, if you break this rule.

And what is your aplication for this sensor ?
Spectrometer is my guess - I can tell you, that range of integration time you will be using is somewhere in 1 to 100ms, not more (if not, you have some bug in optical setup).

There is something called dark output signal and dynamic range of sensor. With higher integration times, dynamic range becomes smaller and smaller to the point, where it is just basically useless.


Anyhow, I suggest black tape is probably not going to work. the package is glass and light will still get in from the sides. You need to get yourself a light-tight box of some sort while you are experimenting, even if you do manage to significantly reduce your integration time.

Not true - it is cerdip with quartz glass window glued IN (not ON) top part, so actually if you manage to cover sensor all over the top side, there are no leaks. What is bad idea is the black tape - sensor is sensitive to some 1300-odd nanometers and what is "black" in VIS spectra might not be so opaque in infrared, right ? I was not suggesting aluminium tape just by mistake ;).
« Last Edit: December 18, 2013, 07:11:19 pm by kony »
 

Offline DajgoroTopic starter

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Re: Linear CCD, how to get it working?
« Reply #29 on: December 18, 2013, 07:58:40 pm »
And what is your aplication for this sensor ?
Spectrometer is my guess - I can tell you, that range of integration time you will be using is somewhere in 1 to 100ms, not more (if not, you have some bug in optical setup).
Yes, actually a friend of mine has all sorts of ideas what to do with that...

Not true - it is cerdip with quartz glass window glued IN (not ON) top part, so actually if you manage to cover sensor all over the top side, there are no leaks. What is bad idea is the black tape - sensor is sensitive to some 1300-odd nanometers and what is "black" in VIS spectra might not be so opaque in infrared, right ? I was not suggesting aluminium tape just by mistake ;).
The chip is flat as kony describes it, and electric tape is sorta ok, unless there is a 60W bulb near by. I never saw aluminium tape at the local electronic/hardware stores.
 

Offline kony

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Re: Linear CCD, how to get it working?
« Reply #30 on: May 17, 2014, 03:17:40 pm »
If anyone interested in hi-res photos of this linear CCD (huge thanks to ZeptoBars for scanning it !) :

http://zeptobars.ru/en/read/Toshiba-TCD1201D-linear-CCD
 

Offline Conrad Hoffman

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Re: Linear CCD, how to get it working?
« Reply #31 on: May 17, 2014, 10:04:41 pm »
Some good advice here. Many things that appear black actually transmit IR like crazy and your sensor will saturate. It will also saturate in a very short time due to dark current. Any light at all bleeding in from an edge can saturate it. Finally, these things are crazy sensitive to static damage. This is strictly a ground sheet & wrist strap project. Be careful with bypassing and spikes on your supplies. You can spend nearly forever trying to get a dead device to work.
 

Offline BarsMonster

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Re: Linear CCD, how to get it working?
« Reply #32 on: May 17, 2014, 11:14:09 pm »
If anyone interested in hi-res photos of this linear CCD (huge thanks to ZeptoBars for scanning it !) :

http://zeptobars.ru/en/read/Toshiba-TCD1201D-linear-CCD

He-he, I am thinking about taking photo of TCD2907DG next, which is a color linear CCD sensor.
Unfortunately, I cannot find datasheet anywhere. Anyone has anything, or at least pinout?
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Offline amyk

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Re: Linear CCD, how to get it working?
« Reply #33 on: May 18, 2014, 12:40:40 pm »
 

Offline BarsMonster

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Re: Linear CCD, how to get it working?
« Reply #34 on: May 18, 2014, 03:06:05 pm »
http://www.datasheetarchive.com/TCD2706DG-datasheet.html close enough?

Not yet, mine has 22 pins, and 6 sensor lines.
2706 has 3 sensor lines and much higher pin count.
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