Re: Jamming Shimano Di2

On Sun, 18 Aug 2024 08:58:05 -0400, zen cycle
<funkmasterxx@hotmail.com> wrote:

You misunderstand. I didn't write that it was simplex. I wrote that it
was originally intended to monitor sensors rather than dynamically
control another 'slave' device. Of course some handshaking is necessary
in order to pair the components and maintain the link. As the technology
and popularity of the protocol has grown subsequent versions gave more
versatility for more control. I know I read that history somewhere, but
It's not popping up in my searches right now.

This might be of interest:
"Shimano DI2 Wireless Reverse Engineered"  (March 22, 2019)
<https://www.youtube.com/watch?v=25Kyh5im_ak>  (19:45)
Note that the Github page with the code is gone.  However, there are
some other interesting projects on his site:
<https://github.com/kwakeham?tab=repositories>
Following search results for "DiHack", I found this:
"DiHack.  Reverse Engineering the Shimano Private ANT Wireless
profile"
<https://github.com/cmoski/DiHack/blob/master/Onenote-notes.pdf>

- Does wireless shift faster? yes, marginally.
- Does wireless shift more accurately? Yes, but a properly set-up cable
system does just as well such that it's barely noticeable.

When races are won or lost by small fractions of a second, any
innovation that offers even a slight advantage is probably worthwhile.
Whether it's financially worthwhile depends on the sponsors
generosity.


--
Jeff Liebermann                 jeffl@cruzio.com
PO Box 272      http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann      AE6KS    831-336-2558