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Re: Optimal board for vision processing
So far the vision processing MORT11 has done has been done with a stripped down dual core AMD mini-laptop (bigger than a netbook) on the robot that is worth less than $200 on the common market. It has the display and keyboard removed. It has proven to be legal in the past but we have rarely relied on vision processing so it often is removed from the robot mid-season. It was also driven 200+ times over the bumps in the field with an SSD inside it and it still works fine. For cameras we used USB cameras like the PS3-Eye which has a Windows professional vision library and can handle 60 frames a second in Linux (though you hardly need that).
That laptop is heavier than the single board computers in part because of the battery. However I would suggest that battery is worth the weight. As the laptop is COTS the extra battery is legal. This means the laptop can be running while the robot is totally off.
The tricky part is not finding a single board or embedded system that can do vision processing. The tricky part is powering it reliably and the battery fixes that issue while providing enormous computing power in comparison.
Very likely all of the embedded and single board system that will be invariably listed in this topic will not be able to compete on cost/performance with a general purpose laptop. The market forces in the general computing industry drive differently.
The cRIO gets around this issue because the cRIO gets boosted 19V from the PDU and then bucks it to the internal low voltage it needs. As the battery sags under the motor loads, dropping the 19V is no big deal if you need 3.3V. As switching regulators are generally closed loop they adapt to these changing conditions.
So just be careful. The 5V regulated outputs on the robot PDU may not operate in a way you desire or maybe provide the Wattage you need and then you need to think about how you intend to power this accessory.
People have worked around this in various ways: largish capacitors, COTS power supplies, just using the PDU. I figure that since electronics engineering is not really a requirement for FIRST that using a COTS computing device with a reliable and production power system is asking less.
Keep in mind that I see no reason an Apple/Android device like a tablet or cell phone would not be legal in past competitions on the robot as long as the various radio parts are properly turned off. It is possible someone could create a vision processing system in an old phone using the phone's camera and use the phone's: audio jack (think Square credit card reader), display (put a photo-transistor against the display and toggle the pixels) or charging/docking port (USB/debugging and with Apple be warned they have a licensed chip you might need to work around) to connect it to the rest of the system. I've been playing around with ways to do this since I helped create a counter-proposal against the NI RoboRio and it can and does work. In fact I can run the whole robot off an Android device itself (no cRIO or RoboRio).
Last edited by techhelpbb : 15-10-2014 at 10:36.
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