I’ve run into two users whose Fez Spiders suddenly stopped working - program won’t run, mainboard isn’t recognized as a USB device anymore. Both users were running the latest NETMF 4.1 GHI/Gadgeteer SDK and corresponding firmware, and their mainboards had previously been reliable. Reflashing the firmware restored the Spiders to health.
This is intermittent enough that I don’t have a solid repro, but I’m wondering if there are well-known operations that risk corrupting the mainboard firmware.
I only have one explanation that would make sense. The device has very low power that it is barely working but then when they try to load a new application, flash fails to write and even causes corruption to the firmware. This is because writing to flash is more se as it has more info.sitive to power. I will hit the “power issue” quickReply button on the second reply.
While USB specifications say ports should provide 500mA, we rarely see a port that can actually provide 500mA. We always recommend the use of powered hubs or a power pack instead of relying on the USB power. Use a powered hub from a known brand, not a cheap hub. If your device has the option of using a power pack (for example the USB Client DP Module) then you can use a power pack instead. 9V 1A is typically recommended but check the bottom of the circuit board for printed voltage range. All power connectors on GHI products are 2.1mm with positive on the inside and negative on the outer ring.
Not using a powered hub or power pack can cause:
[ul]Unexplained behavior
Device does not function
Device functions intermittently
Device functions but network fails
Device functions but SD card fails
Device functions but firmware update fails[/ul]
(Generated by QuickReply)
Ah, that makes sense. Thanks, Gus, I’ll pass that along.