Getting image sensors in low quantities - Page 1
Forum section: electronics / general

author: Kelbit
author_rank: Regular Contributor
timestamp: September 25, 2017, 06:16:49 am
content: Wasn't sure where to post this as there isn't an optics subforum. Basically as the title says - any ideas as to places to source small quantities (dozens) of image sensors relatively inexpensively?The reason I ask is that I'm working on a side project - designing a two axis sun sensor for small satellites like cubesats. A sun sensor is used for attitude determination on satellites - by accurately sensing the position of the sun in the sky, you can get a pretty accurate estimate of your spacecraft attitude. I'm planning to build one using a pinhole and an image sensor. The pinhole projects an image of the sun onto the plane of the image sensor, and some simple image processing can be used to figure out the azimuth and elevation of the sun.It seems pretty hard to actually find image sensors which are affordable. DigiKey sells a few parts, but the cheap stuff is all OmniVision which requires an NDA for datasheets, and I don't think my volumes are going to be anywhere near high enough to be worth their time - if I actually develop this into a product, I'm looking at selling maybe a few dozen units per year. Sony and Panasonic don't even have parts in these kinds of distribution channels, it seems to all be factory direct or via Avnet with super high MOQs.My best bet so far is ON Semi, who actually seems to have a few of their lower-cost sensors available on Mouser (eg:http://www.mouser.com/ds/2/308/AR0130CS-D-888239.pdf), and their datasheets actually expose enough information to use the part. Unfortunately, it's hard to find a *monochrome* image sensor that's cheap and low-quantity friendly. The ON Semiconductor part I linked is only available from Mouser in a Bayer array configuration, and I would greatly prefer a monochrome sensor if possible. They do have a monochrome part for $20 each which would be great, but the MOQ through Avnet is something like 240 units. In a pinch, I could do something like apply a different gain to each R, G, and B element based on the sun's output spectrum, but getting that well-matched sounds like a pain.Anyone have any idea where I could get a cheap (<$40) image sensor in singles with a datasheet? My dream part would be:1/2" or 1/3" image formatMonochromeSimple CMOS parallel interface (although I'll use LVDS if required)Minimum fancy SoC features - fancy features means more that can go wrong with radiation exposure. Ideally, I just want to set a gain and read out pixelsCMOS preferred but CCD is okay if the package isn't enormousCheers!

author: amyk
author_rank: Super Contributor
timestamp: September 25, 2017, 06:57:19 am
content: Plenty of datasheets and example code for OmniVision sensors floating around... they're cheap because tons of Chinese smartphones use them.

author: tszaboo
author_rank: Super Contributor
timestamp: September 25, 2017, 10:04:40 am
content: Did you talk to Avnet? Sometimes they will sell you a part below the MOQ. It depends on the part. They just order some extras for bigger customers and give the extras to you. Call them on the phone, negotiate, use the people skills!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 25, 2017, 10:57:27 am
content: Mono sensors in general are fairly rare as few people use them. If you can use RGB that will probably be easier. Perhaps use in YUV mode and ignore the UV.Datasheets from some Omnivision sensors have escaped, but are not the full story as they need register initialisation, and there are typically many "magic" values. OV7670 and OV9650 are the best documented. These are reasonably available as FFC module+lens via Aliexpress, maybe also chips if you look harder, and probably cheap enough to buy enough for your entire production in one go to guard against nonavailability.If it's not CMOS paralell it will probably be CSI MIPI, which will be a pain to deal with, and even less well documentedIn your situation I'd use an OV9650 module and remove the lens and/or housing. this also avoids the need to deal with the BGA sensor.

author: grifftech
author_rank: Frequent Contributor
timestamp: September 25, 2017, 07:19:20 pm
content: buy some cheap cameras and salvage the sensors