Better Downward Camea

[mrandt]

You will find a brief description and downloadable ZIP containing all files on my website:
http://malte-randt.de/3d-printable-came ... p-machine/

Best
Malte

[dave]

I messaged about them LED.

I have the Logitech cam on order.

Can you sell the a printed module and LED boards. Or at least the LED board with LED.

If the price is ok I rather save myself some hassle. so many things to build right now.

I Messaged you via PM

[Spikee]

I have hacked my C270 webcam as the downward looking camera. I have done automatically placement (via pickup location) 0.5mm qfn and it was accurate enough.

[WayOutWest]

Here is a picture of the PCB:

Way way cool. Any chance you are willing to share the GERBERs?

Six of these trapezoid boards connected by solder joints on the corners make up the LED hexagon you saw in my pictures. Btw, credit were credit is due - the design was inspired by Brian Dorey http://briandorey.com/post/DIY-Pick-and ... Array.aspx

Also worth noting is AZIZ, the microscope light, from a few years earlier. Even if it wasn't so cool it deserves a mention just because of the completely awesome name. The videos are neat too where he demonstrates individual control of the bulbs, especially at 4:16 in the video where he shows how off-angle illumination at the correct angle makes an enormous difference in reading IC labels . It's not surface-mount though.

AZIZ! Light!

http://www.tangentaudio.com/electronics/aziz/

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[mrandt]

Hey Adam,

that quote is from 5th element - I remember the movie

I like the microscope light and wonder if it is worthwhile to build something similar in SMT - there are so many different LEDs available that it might be possible.

For the hex light I have to give credit to Brian Dorey:
http://briandorey.com/post/DIY-Pick-and ... Array.aspx

However, the boards and 3D printed mount are my own design. I have already shared the STL and could also dig out the Gerbers. Just note that - in order to save cost - the boards are not V-scored or anything but have to be cut using a CNC mill or desktop circular saw (1mm blade or thinner) after reflowing. The white stopmask layer is just for the looks - any other color would also work I suppose as the LED light is very directional anyways.

Each board has pads for a current limiting resistor if you want to operate the light with fixed voltage. Otherwise you may shorten a solder jumper and connect a constant current source of your choice. When using PWM or switching regulator make sure frequency is high enough to avoid rolling shutter effect on CMOS cam.

Will let you know once the Gerbers are available.

Regards
Malte

[mrandt]

Can you sell the a printed module and LED boards. Or at least the LED board with LED.[...]I Messaged you via PM

Hi Dave, sorry for keeping you waiting. I must have missed that message. Will get back to you via PM.

[mucek]

Any problems with full HD cam as downlooking camera? Have an option to get Logitech C920 cheap ...
Processing computer is i5, 8 GB RAM, WIN10, I guess there shouldn't be problem for it?

Regards,
G

[JuKu]

I guess there shouldn't be problem for it?

In principle, no, there shouldn't. The added processing requirement will have an effect; maybe small but still. Once my ordered high res cameras arrive, I'll add to the software control of where the scaling happens (tradeoff between speed, accuracy, field of vision etc).

[mrandt]

Hey Gregor,

if you find a good way to mount the C920 it should work. Make sure it is fixed well and cannot tilt or bend. I also use a full HD cam (1920x1080) in a custom made case with good results. I might switch to the acclaimed Andonstar microscope cam for better mechanical stability (easier to mount) though.

The CMOS chips in Logitech cams are great and I believe all their HD cams support both MJPEG and H.264 at reasonable frame rates.

I think that one camera might have a motorized, optical focus (for auto focus) which could cause problems. Either you have to find a way to adjust and permanently set the focal range in driver / software, or you can simply open the case and cut the powerlines to the motor (in lense assembly) at a convenient setting.

For processing in software, the picture will be centered so the viewport in LitePlacer is limited to a small rectangle in the middle of the real image and will only utilize a fraction of the available resolution. Thus, components will appear very large (not necessarily a bad thing).

I think improving camera connection and adding more options for HD cams is on Juha's todo list:

- Most cameras support more than one resolution (set via USB connection) and if we only want to use lower res anyways, it might be better to use that setting (and save bandwidth on USB) rather than scaling down in software later.

- Also, I wish it would be possible to set aspect ratio, viewport dimensions and scaling for camera pre-processing. Rotating or flipping images might come in handy as well.

- Reeza and some people on the forum have also experimented with setting and adjusting exposure, aperture, brightness and white balance for USB cams through software which greatly improved computer vision results.

Best regards
Malte

[mucek]

Hi!

Thans for your answers. Regarding to https://www.youtube.com/watch?v=94lDYZgihT4 C920 should have fixed focus.
However, I am still wondering if go into it: 40 EUR vs. 20 EUR (for C270) is still double price and I am not sure if difference is so big (as already original camera does its job quite splendid and C270 is already a big improvement)

Regards,
Gregor

[edit] Found Andonstar microscope on ebay for 50 EUR: as it seems to be proven stuff, I'll take this