Justin:
On Friday, January 17, 2014 4:11:11 PM UTC-5, [email protected] wrote: > > Hi everyone, > > I am part of a student-run society, at university, that is responsible for > designing a CubeSat satellite. We are attempting to use the BeagleBone > Black as the on-board computer, however we have concerns with bit flips and > single-event upsets that can be caused by radiation. Of course we will be > using some shielding, but I would be interested to know if similar projects > were undertaken and also what you guys think about the BBB's tolerance to > radiation. > I once ran a Hitachi SH-2 in Indiana University's proton accelerator (which isn't nearly as powerful as actual space) for a few hours, and could trigger SEUs anywhere I wanted to in the SoC about as fast as I could turn on the beam. I'm guessing that the smaller process geometry, lower operating voltage, and greater complexity of OMAP will make it perform even worse. (For the record, I have no knowledge of OMAP in CubeSats because I haven't been paying attention lately.) That's not to say that you can't use the BBB in LEO, but if you do then you'll need to be prepared to mitigate the damage or your overall mission will fail in short order. In our case, we had a VERY sensitive current meter in the circuit that would power-cycle the whole board at the earliest sign of a latchup. We also planned to do periodic power cycles to clear micro-latchups that wouldn't sink enough current to trip the current sensor. We had several layers of double-sided watchdog timers, and we checked every one of our drivers (we weren't running Linux) to make sure we didn't have any polling on status bits that wouldn't eventually time out in some other way if the hardware got stuck. Finally, the current threshold that would trigger a power cycle was software-controlled, so we could raise or lower it depending on what we knew we were doing at the time. Tragically, the board never flew due to a long list of bureaucratic snafus, delays, and the other usual suspects. But it still taught me quite a bit about how to harden software for the real world. :-) -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
