View Full Version : [Interesting] Raspberry Pi custom services

11-28-2015, 06:19 AM
Browsing for some details about the new Raspberry Pi ZERO I stumbled on this service from element14 for customisation of Raspberry PI: www.element14.com/custompi (http://www.element14.com/custompi).

I think there will be a lot of advantages for a "robotics" version of RPi where all connectors are removed (USB and Ethernet), maybe replace the USBs with the 4 pin MOLEX and also maybe leave the pin header out - optional to be soldered if really needed (or soldering a 90º header pin for example). It would significantly reduce the weight of the board and will make for a very thin footprint. I can only imagine the advantages of sandwiching half a dozen RPis and leveraging ROS to build a really serious distributed platform (of course if we also come with a practical solution to network them without using a 0.5Kg network switch...).

Would you think it would be worth pooling together to have an enquiry to see how much would cost to create (say) 50-100 simplified boards? And would someone at Trossen would like to engage in this (apparently the service works only for companies)?

[Edit] Actually the minimum order is 3000-5000 (http://www.element14.com/community/docs/DOC-79064/l/raspberry-pi-customization-service) which might be a bit too much just for this community only.

11-28-2015, 06:38 AM
I can only imagine the advantages of sandwiching half a dozen RPis and leveraging ROS to build a really serious distributed platform (of course if we also come with a practical solution to network them without using a 0.5Kg network switch...).
I had been thinking about a pair of RPi-A+ with cameras for stereo vision since the USB of the RPi's CPU is USB-OTG, so can act as a device when not connected to the USB hub/ethernet IC of the RPi-B/RPi-B+/RPi-2B. Unfortunately, Rasbian does not include the usb gadget kernel modules by default, so have to either rebuild the kernel with the modules or figure out the changes necessary to build them independently like I had for the usbtv drivers. If the RPi-Zero had the camera header, it would be even more amazing but could still be useful as a USB device (USB gadget ethernet) for distributed computing since all you would need is a powered USB hub.

11-30-2015, 01:49 PM
I also think the Zero is quite interesting! It's like a "tiny" or "opencm" board on steroids.
Unfortunately, the Zero doesn't have the camera port :-(

I briefly considered the dual-Pi-dual-cameras for stereo as well, but we're still missing the important sync bit (and the RPi camera is rolling shutter, right?)
So, I'm not sure it's any better than dual-USB-webcams, really.

11-30-2015, 02:48 PM
Dual USB webcams would be sharing a single USB-OTG port on the RPi via the hub IC that also provides ethernet. The various ODroid boards may fare better with their multiple USB ports on the CPU. Most USB cameras also have rolling shutters, so no worse off. Better, the RPiCamera is accessed by the GPU, so it is even faster at higher resolutions and permits processing of images prior to sending them to a central CPU for matching.

11-30-2015, 04:53 PM
How hard could it be to build two matched, genlocked, full-shutter cameras on a PCB? Really?

It seems like there's a lull in stereo cameras for semi-pro/research type applications, while everybody is busy with the structured light diversion. (Which will approximately never work in sunlight.)

11-30-2015, 05:25 PM
There are several stereo cameras like that, but most are upwards of $500. The Duo3D (https://duo3d.com/) is one of the nicer looking options, although it is still limited to widescreen VGA resolution.

The plan to ensure consistent alignment of RPiCameras was a PCB with a pair of 8mm x 8mm cutouts to directly grip the camera housing instead of relying on the irregular alignment of the camera module on its PCB. Also considered a version with eight 5050 NeoPixel LEDs to have four spaced around each camera cutout.

11-30-2015, 06:50 PM
Neat! Although with 170 degree lenses and 30mm baseline, it won't see very far with WVGA resolution ...
It seems almost perfect for a Mech Warfare size bot, though!

... and IR only? Color is super helpful when finding stereo similarities/disparities!
(Btw: scanline based disparity maps are kind-of dank; I think patch-based ones could work better but haven't found any code that really talks about that, so perhaps that'd be new research?)

03-20-2016, 07:29 AM
Actually I have a stero camera that was only $200.00 plus shipping. The OrSens is a Kinect-like sensor calculating the depth map on the board: ideal for development of successful engineering solutions using computer vision. It took six months to get here and, I am still trying to find a good mount for it and may need to go to a bec for the PI3. Oh yea, to works in sunlight a little better than in room lighting.

03-20-2016, 11:22 AM
Is it Kinect-like in that it uses structured light, or is it Kinect-like in that it has DSP on the board?
Specifically, if it uses two separate cameras (instead of a light projector and one camera) then it's "true" stereo and probably better.

Edit: I found the website. It looks great! Two cameras, on-board DSP, should work great in sunlight.

03-21-2016, 01:39 PM
Did not get a sdk SD like they said, but the download from github compiled and all the examples run, with a build in the future that will have slam mapping in ROS they say, So I am pretty happy with this sensor and am so wanting to integrate it into my HROS1.

03-21-2016, 05:51 PM
That sounds great! Do you just get the depth map, or do you get a color image as well?

03-22-2016, 07:01 AM
Both, all there demos are working, even some 3-D thing that takes some kinda goggles or something, I'll figure it out.
(Note. There production runs are sold out almost before there done and seems like six months between runs and it looks like there hand calibrated so, LOL. I was patient to get one, and that is not my strong suite in Life.:wink:)