#841  
Old 25-11-2017, 07:24 PM
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Hi Patrice,

I am not 100% sure but the way I understand the point 3, Rim is saying that the one side of diode VD4 should be GND instead of +5V. This should be done relatively easily by cutting the +5V track on the PCB and then grounding the diode VD4.

Also +15V supply to the sensor is needed only for the frame reading and can be GND during exposures. This will reduce heat and noise. However, for short exposures +15V must be left on.

Rim mentioned that a firmware change can do this. Someone will need to confirm but I think pin F7 on ATMega controls the voltage. So, changing the voltage on F7 in firmware could do the job

Beware that this is my interpretation of the google translation. It does not mean it is what Rim said. I just don't want anyone blowing up their camera because of what I said is not correct


Very nice image
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  #842  
Old 25-11-2017, 07:57 PM
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More about each point:
Quote:
1. In the CAM86, this effect is weaker, but it is also recommended to feed the ATMega328 and 74HC86 processor from a separate power regulator. Those. The Ft2232 power supply circuit must be decoupled from the ATMega328 and 74HC86 power circuits.
This improvement would require a separate PCB with 3.3V power supply. But I never saw those diagonal stripes in my 2 cameras so probably it is not worth doing unless you are having problems.

Quote:
2. The MAX743 transducer should be better out of the board and even the camera in general. This will save you from a lot of problems with interference and unnecessary noise in the picture. Especially in CAM90.
Requires new PCB design.

Quote:
3. During the accumulation of the signal, instead of +15 volts per sensor and on the amplifier chip, a "supporting" +5 volts supply is supplied. So, this voltage + 5 volts can generally be removed to zero. Those. Connect the anode (+) of the diode to ground instead of +5 volts.
Generally speaking, even the +15 volt supply voltage can always be removed, only when the frame is read, it will be better - the operator and sensor will be warmer less, which will improve cooling and reduce noise. For short exposures <1 sec will need to keep +15 permanently. This will require upgrading the firmware.
Can probably be done relatively easily. As I said before cut +5V trace and GND the diode. For +15V a firmware will need to be modified.

Quote:
4. ...it is necessary to properly connect the power wires supplying the "+" and "-" peltiers to the source of the power switching transistor, otherwise there will be some banding of the image. It is necessary to drive these wires separately from the input connector and it is better to use a separate connector for powering the cooling power section.
In the modernized firmware, the switching is carried out during the pulses of the vertical (V1..V4) sweep.
This would require a new small PCB with optoisolator and FET. But if FET is kept off or on during the frame read (as it is now) then there is no problem.

Quote:
5. Humidity sensor
Don't have one, can't really comment

Quote:
6. ...when wiring the earth's feet of the sensor, it is better to pour the polygon through the "thermals" to reduce the loss of cold through the legs.
Requires a new PCB.

Quote:
7. Reduce the hermetic chilled volume.
Something to think about. But our plan was to include the desiccant tablets inside the housing which would suck up the moisture anyway.

Quote:
8. The rest of the chamber is filled with Silicone Sealant Pentelast 710. or other similar.
Makes any repairs very difficult.
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  #843  
Old 25-11-2017, 10:25 PM
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Confused about the point 3, our firmware/driver already switches off the +15V for >1s exposures. Perhaps Rim only suggested changing +5V to GND on the diode

The mysteries of the google translation
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  #844  
Old 26-11-2017, 01:10 AM
pat30 (Patrice)
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Quote:
Originally Posted by luka View Post
Confused about the point 3, our firmware/driver already switches off the +15V for >1s exposures. Perhaps Rim only suggested changing +5V to GND on the diode

The mysteries of the google translation
The Russian translation is complicated, it is better to wait for the schema!
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  #845  
Old 26-11-2017, 02:43 AM
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Not sure if the updated files are coming soon/ever. I posted a question on the Ukrainian forums.
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  #846  
Old 26-11-2017, 05:05 PM
pat30 (Patrice)
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Quote:
Now it is not necessary to modify. VD4 anode should be connected with +5v.
There is change, now point 3 invalid, don't touch.
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  #847  
Old 26-11-2017, 06:55 PM
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Interesting, the change works only for Cam90 but not for Cam86. They do have different sensors which probably explains why.
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  #848  
Old 26-11-2017, 06:57 PM
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I keep forgetting, the source code is out on the github for all to see/modify/use. No new updates.
Links:
ASCOM driver
DLL
Firmware
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  #849  
Old 26-11-2017, 07:14 PM
pat30 (Patrice)
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Quote:
Originally Posted by luka View Post
I keep forgetting, the source code is out on the github for all to see/modify/use. No new updates.
Links:
ASCOM driver
DLL
Firmware
Thank you Luka , even if for me it's Chinese.
I'll have to learn coding one day ...
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  #850  
Old 26-11-2017, 07:58 PM
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About a year overdue but better late then never
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  #851  
Old 15-12-2017, 04:56 PM
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Hi everybody,

I would like to introduce Oscar, a new member of our software development team

Oscar's contribution to our ASCOM driver started with a real bang, he developed a full PID solution for the camera temperature control, of course, all in the spirit of open source.

So, in the name of all of Cam86 users I would like to say and to Oscar.

The new drivers/firmware are on our github page, see the links in the top of the README section. As always, use at your own risk and report back with any bugs and suggestions. You will need to tweak the PID parameters for your system but the default values seem to represent a good starting point.


Finally as a little New Year's sweetener I did few little interface tweaks and bug fixes. The temperature info now shows the set temperature as well. Also it is possible to to double-click on it to set the temperature independently of the imaging software. Note that this manual temperature settings may be overridden by the imaging software.

Luka
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  #852  
Old 18-12-2017, 03:28 PM
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New version 0.7.8 of the ASCOM driver is on our github.

Please update as soon as possible.

Changes:
- Fixed a bug where manually set temperature was resetting itself.
- Manually setting temperature requires double-click now (as originally intended).
- Minor interface tweaks

Thanks to Oscar for noticing the temperature bug.

As always, use with care and please report any bugs and suggestions.
Luka
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  #853  
Old 18-12-2017, 10:38 PM
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Hi guys! Thank you for your wellcome. I hope to keep contributing to this great project.
Rough-tuning the PID controller is quite easy. First, increase the value of Kp (in steps of 5 units) until setpoint is overshooted. Then, come back to the previous value. Now we must have a stable control, but setpoint is not reached. Then increase the Ki value in steps of 0,05 until setpoint is reached. By now, I don't see as neccesary to use the derivative term.

I think that you can safely use a value of 40 to start tuning the Kp. When Kp is tuned, a starting 0,2 value for Ki can be used. Of course, these values can be too much for your camera, use with caution and at your own risk ;-)

Oscar
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  #854  
Old 18-12-2017, 11:21 PM
gehelem (Gilles)
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Quote:
Originally Posted by Astrococo View Post
Hi guys! Thank you for your wellcome. I hope to keep contributing to this great project.
Rough-tuning the PID controller is quite easy. First, increase the value of Kp (in steps of 5 units) until setpoint is overshooted. Then, come back to the previous value. Now we must have a stable control, but setpoint is not reached. Then increase the Ki value in steps of 0,05 until setpoint is reached. By now, I don't see as neccesary to use the derivative term.

I think that you can safely use a value of 40 to start tuning the Kp. When Kp is tuned, a starting 0,2 value for Ki can be used. Of course, these values can be too much for your camera, use with caution and at your own risk ;-)

Oscar
Thank you Oscar

May i suggest to have a look at my little Excel game :
https://www.diycam.fr/index.php/fr/1...ure-avec-excel
(use the english flag top right to translate)
It should be adapted with new driver, but it's a very simple way to batch a few tests

I'll get back to that once i'll have finished my second cam

Gilles.
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  #855  
Old 19-12-2017, 03:59 AM
pat30 (Patrice)
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There was a reboot site ??? my message from yesterday is no longer there

It said thank you and welcome to Oscar in the adventure .
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  #856  
Old 20-12-2017, 01:21 AM
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There was a hard drive failure in the server. Most likely some posts just before the failure were lost.
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  #857  
Old 22-12-2017, 05:16 AM
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Quote:
Originally Posted by gehelem View Post
Thank you Oscar

May i suggest to have a look at my little Excel game :
https://www.diycam.fr/index.php/fr/1...ure-avec-excel
(use the english flag top right to translate)
It should be adapted with new driver, but it's a very simple way to batch a few tests

I'll get back to that once i'll have finished my second cam

Gilles.
Hi Gilles and Patrice, and thank you for your welcome. I have modified the MSExcel sheet to include the new function calls, but in spite of copying it into the same directory, I receive an error telling that cam86ll.dll can't be found. If you can have a look to the xls file, you can download from here: TempTestVBA-11.xlsm

Last edited by Astrococo; 23-12-2017 at 12:02 AM. Reason: Change link
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  #858  
Old 02-01-2018, 06:32 AM
pat30 (Patrice)
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Happy New Year my friends, that 2018 gives you a clear enough weather to make beautiful pictures with the Cam86
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  #859  
Old 05-03-2018, 03:08 AM
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Hi everybody,

Things have been quiet for a while but the development has been ticking in the background. I have been trying to make the camera switch the TEC on/off during the frame reading instead of just having it on or off.

I have tried a few different approaches. It is doable but... and there is a but, it will cause noise in the images, at least with my camera. The attached image was taken with a testing firmware which switches the cooler on/off 4 times during the frame read (in between the row changes). Unfortunately 4 horizontal stripes are visible, roughly every 1/4 of the image.

The attached image has been stretched to show the stripes better. The camera was not cooled for this test, I would expect the cooled sensor to show the stripes better as the background noise will be less.

I have attached the testing firmware that I used. Can someone else flash it and do the test. I would like to see if the stripes are there visible with different designs of the power circuitry for the TEC. I am thinking of adding an inductor to smooth out the large current spikes by the TEC??? Not sure.
(you will need to flash the original firmware to restore the camera back to normal function)

Any other ideas?

Luka
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  #860  
Old 05-03-2018, 04:18 AM
glend (Glen)
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Luka, the work that Rowland and i did on cold finger cooled Canon TEC power regulation dealt with similiar noise, which was traced to poor common earthing of the cold finger to the chassis and the regulation circuit. Nothing should be allowed to 'float'.
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