In parasitic mode you can power the sensor using the data line (the Vin pin on the sensor is grounded). This way you can run the sensor with only one wire (+ GND). The sensor basically "sucks up and buffers" enough power from the data line to measure temperature and return a reading. It does not work too well on long wires and/or if the power is not that great.
By the way, I just rewired the sensor the "classic" way and it works fine.
The DHT22 and the TEC work fine as well .
That is a very nice image Patrice. Thank you for testing the driver.
I have sent the driver to Vakulenko several weeks ago as he wanted to add it to his github instead of having two separate codes. As far as I can see he uploaded the firmware, the low level driver and the viewer source code but not my ASCOM driver. Not sure what is going on there.
Is everybody's DHT22 working OK? Did you compare the readings with any other humidity sensors?
I started to test my camera again and it is incorrectly showing 20% humidity while it should be about 50%. The sensor is almost new so I am not sure if it broken or there is something wrong with the software.
Also while speaking of DHT22, the stated accuracy of +-2% is only for humidity over above 20%. It gets as bad as +-5% below 20% humidity. Very inaccurate for our purpose.
Also these sensors are notorious for breaking. Apparently most last less than 1-2 years.
I am looking into BME280 sensors now... +-3% accuracy across the whole range.
hi
mine is working, but you're right, we don't have to expect more than it can do...
Comparison with another humidity sensor : nope
Comparison with another temp senor : yep
in fact, it's still interesting and gives an indication. When you open your camera for some reason, you can see if you close it well or not.
you can also be warned if your humidity sudenly raises.
I think if you consider there are only 4 values ("Good" "Bad" "Better" "Worse"), it does the job.
Gilles.
I have not heard anything from Vakulenko. He pushed all the code to his github apart from my ASCOM driver 2 months ago and there was nothing since then.
What's the current state of play? Particularly interested in the cooling setup.
Cheers, Dave
Hi Dave,
I can't say, but i'm sure Brendan and Luka are working hard on their setup
On my side (in France) this project is more than ever living, the boxing part is really the hard one.
You can follow our french forum if you want : http://www.webastro.net/forum/showthread.php?t=141764
Or find information we've tried to gather here (you can easily use the "google translate" button on top) : https://www.diycam.fr/index.php/fr/
It contains some informations regarding TEC cooling
Gilles.
I Have a cam86 PCB ready dark test etc all good. Took some time fixed some vertical noise with was DD11 capacitors again.
Anyway I've identified the issue and tacked on a 200uf 25V cap on DD11 output. No more dark noise.
Anyway I wanted to optically test this PCB. Bearing in mind I have no ability to mount it or fix a lens to it atm. So I was thinking a pin hole camera test...anyone done this? Any tricks?
Edit:
Oh meant to say...I had vertical stripes across my darks, removing 2 of DD11 caps doubled the number of these stripes. Placing a 220uf 25V on DD11 out...fixed. I've seen it written vertical stripes on the left are DD11 capacitor issue. Well yes...even vertical stripe noise across the sensor is also an issue with these caps. FWIW.
Last edited by wasyoungonce; 19-05-2017 at 03:27 PM.
Gary many thanks but not yet. I'll try a pinhole camera and Lukas trick with a lens and loop image taking first!
I'm sure its ok atm and I have done images with objects placed on the sensor...yes they work I can see them. But I just wanted to ensure with some methodology before pronouncing it good.
So I was thinking a pin hole camera test...anyone done this? Any tricks?
No tricks, pinhole works great for camera testing
Place pinhole 4-5cm from the sensor. You need light-tight enclosure around the sensor, I have used from plastic tube to toilet paper tube