Fixes issue #1533 on Contiki

[PalmaITEM]

The issue in contiki-os/contiki#1533

Is solved by adding the delay in the "invoke_bootloader" after the entire invoking sequence.

[g-oikonomou]

Sorry, I was perhaps not clear in the Contiki discussion.

We need both delays - the first one exists for different reasons

[alignan]

Yes, we need both of them. I can confirm this works.

The explanation is simple: the on-board PIC detects the RTS/DTS sequence, waits a bit, then replicates onto the CC2538's PA3/RST. We need this delay that was introduced by the VM USB forwarding and later by the intelhex and python-magic.

[PalmaITEM]

Understood, I fixed the pull. Sorry for mixing things.
(I didn't know if it was best just to close the request, I'll leave it to you)

[PalmaITEM]

Hi @g-oikonomou ,
Hi @alignan ,

I have an update on this issue/pull request.

Using a fresh ubuntu machine (native, not a VM), the same problem appeared.

Solutions:

• Increasing just slightly the sleeps (to 0.005 has worked flawlessly so far)
• Keeping the sleeps as they were but installing python-magic improves but it still fails now and then (it seems non-deterministic and sometimes it even works without the second sleep, sometimes it doesn't, so I guess it's still needed)