Honda Civic 2022: Add traffic sign detections

[landonh12]

Found the message and signal for speed limit detection in 2022+ Honda Civics. As soon as a speed limit sign leaves the frame on the right side of the camera feed, a CAN message with ID 0x1EF is sent with the speed limit in MPH at byte 5. See below:

I am in the US, and I'm not sure if other parts of the world have a separate message for KPH and for signs dissapearing on the other side of the image in RHD countries.

[kevinharbin]

Here are the fields that I recorded, with a couple notes.
I was able, once or twice to trigger the sign detection by walking a printed sign past my parked car.
Plus, here is a note from the manual for any testing you might do.

Hex	Binary	Seen in Car
00	00000000	OFF
61	01100001	5mph=1*5
62	01100010
63	01100011	15
64	01100100
65	01100101	25
66	01100110	30
67	01100111	35
68	01101000	40
69	01101001	45=9*5
6a	01101010
6b	01101011	55=11*5
6c	01101100	60
6d	01101101
6e	01101110	70mph=14*5
6f	01101111
70	01110000
7c	01111100
7d	01111101	No sign detected.
7e	01111110	camera not available, crossed out sign [Malfunction/too cold/etc]

[landonh12]

Opening this up for review - I've sort of stalled on the work. Main thing that needs to be reviewed is whether or not the messages I added are in the correct files. I don't have another Honda to test on so I'm not sure if these messages are specific to 2022+ Civics. Will post in the Discord to see if anyone else can find these on their Accord, Pilot, Ridgeline, etc..

[vanillagorillaa]

LGTM - These signals are also present on the 2023 Pilot (port in progress). Would be nice to get more values for the road sign signal. Wonder what else it detects (and it's value) besides stop signs.

[landonh12]

One detail to add - it seems that the speed limit does not follow units, only the number seen on the sign.

[landonh12]

An update to this PR:

I drove a 2024 Honda Accord as a loaner from a dealership. The full screen dash display also shows additional information, such as stop signs, school speed limits, etc. So that's likely where this data from Bosch ADAS gets used.

This link outlines different traffic sign recognition features, see the "Other conditions" section: https://techinfo.honda.com/rjanisis/pubs/OM/AH/A30A2424IOM/enu/details/131222047-299074.html#d_131_2220_47_299162