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newRPL - can't restore to 39gs
03-18-2019, 04:24 PM (This post was last modified: 03-18-2019 04:27 PM by Claudio L..)
Post: #8
RE: newRPL - can't restore to 39gs
(03-18-2019 03:49 PM)3298 Wrote:  While I have no knowledge about how USB works or how newRPL uses it, a size limit reminds me of VPN affecting UDP traffic by lowering the max size, which can lead to dropped packets because unlike TCP packets the UDP ones cannot be fragmented. Let me throw an idea at the wall and see if it sticks: Conceptually USB hubs and VPN have something in common in that they tunnel traffic ... Are you using a USB hub? If so, try a direct connection.
(The culprit may not actually be a size limit; slow transmission that causes long packets to not be received in entirety before a timeout is over would probably have similar effects. The primary suspects for such bottlenecks are of course devices that literally sit in the middle of the connection, but it might be a driver too since those sit in the software section of the line, so to speak.)
newRPL uses a standard HID interface, so there's fixed-size packets of 64 bytes. newRPL uses a couple of bytes to identify packet type and send a stream of tiny packets.
The code { « 1 1 + 2 2 + 3 3 + 4 4 + » } compiles to exactly 64 bytes in size, so it would require 2 packets (because a few bytes of overhead on each packet).
But back to the original problem, the first 4 letters "NRPB" are not arriving well, and that's the very first packet. I'm thinking it might have to do with Windows and its extra byte. I don't remember changing the version of libusb I used to build the sources, but perhaps this problem has always been there we just didn't catch it.

EDIT: By the way, using standard HID means there's no driver getting in the way.
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Messages In This Thread
newRPL - can't restore to 39gs - franco51 - 03-13-2019, 02:19 PM
RE: newRPL - can't restore to 39gs - 3298 - 03-18-2019, 03:49 PM
RE: newRPL - can't restore to 39gs - Claudio L. - 03-18-2019 04:24 PM
RE: newRPL - can't restore to 39gs - bzoom - 03-27-2019, 02:13 PM

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