Tire Pressure Sensors

From Hive13 Wiki
Revision as of 20:12, 30 September 2013 by Craig (talk | contribs) (Created page with '== Overview == Automobiles have wireless Tire pressure sensors. This page stands as a reference page for research in regards to Tire Pressure Monitoring System (TPMS). == Wire…')
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

Overview

Automobiles have wireless Tire pressure sensors. This page stands as a reference page for research in regards to Tire Pressure Monitoring System (TPMS).

Wireless

There isn't a standard for wireless communication but it is typically RF (UHF) and they typically communicate at 125Khz but also have chips that will communicate at 300Mhz-450Mhz. The Wakeup signal from the ECU is typically 125Khz and the communication back is on the 300Mhz-450Mhz range as modulated Amplitude-shift keying (ASK). They use the Manchester encoding [1] scheme and the packet format looks something like:

preamble|SensorID|Sensore Data

Example:

preamble|SensorID|Pressure|Temp|flags|checksum


Protocols

They communicate with the vehicle either with CAN or LIN protocols. These more commonly use LIN because of the lower cost.

Security Concerns

Primarily Identification. Tracking of vehicles while driving. Using the Uniq ID to trigger an IED when a target vehicle drives over it. Etc.

http://www.cse.sc.edu/~wyxu/papers/TPMSUsenix.pdf

See Also