MrBool
Posts: 104
Joined: Sat Jul 05, 2014 9:51 am

Flashing the Compute Module issue

Tue Nov 07, 2017 5:55 pm

During flashing the 250 pieces of Compute Modules I noticed that in two cases CM does not pop up under Windows as a disk. Rpiboot messages are the same as for others CMs (without any errors). Do you have any advice?

gsh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 1445
Joined: Sat Sep 10, 2011 11:43 am

Re: Flashing the Compute Module issue

Thu Nov 09, 2017 12:52 pm

One issue we've seen is with poor quality USB cables, we've found that the Pi's device mode is more susceptible to changes in characteristic impedance than other devices so you need to make sure you are using a good quality cable

The one I was using had a characteristic impedance double the specification (i.e. there was no shield and the pairs weren't twisted). The problem I found was that it would get through the first stage but would then fail to complete the second stage (i.e. re-enumerate as a mass storage device)

Gordon
--
Gordon Hollingworth PhD
Raspberry Pi - Director of Software Engineering

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