Automotive networking - Local Interconnect Network(LIN)

1. Local Interconnect
Network
JABEZ WINSTON C -15MU01
JAGADEESH S -15MU02

3. Why LIN?
 Use of CAN in certain automotive applications can be a overkill
 Highly Economical
 UART / SCI peripheral can be used to implement LIN
 Use of simple internal RC oscillators instead of external crystal oscillators
 No protocol license fee

4. Why LIN is not a replacement for
CAN?
 CAN can operate at higher speeds
 Superior error detection scheme (CRC)
 Fault tolerant capabilities

5. Brief Technical specifications of LIN
 6 bit protected identifier
 Content based addressing
 Speed - 19.2 kbps (Max.)
 8-bytes per frame (Max.)
 16 nodes (Max.)
 Half Duplex
 8-bit Checksum
 Single Master – Multiple Slave configuration
 Bus Topology

6. Typical LIN bus

7. Abstract view of LIN
 A programmer needs to be concerned with the
 Message ID – 6 bits
 Data – up to 8bytes
 Master manages the bus access arbitration scheme entirely
 The Master sends a Frame Header and the concerned slaves respond.

8. Abstract view of LIN

9. Tasks in Nodes

10. MASTER TASK STATE MACHINE

11. Frame
processor

12. Frame types
1. Unconditional frame
2. Event-triggered frame
3. Sporadic frame
4. Diagnostic frame
5. User-defined frame
6. Reserved frame

13. Applications of LIN
Application segments Specific LIN application examples
Roof Sensor, light sensor, light control, sun roof
Steering wheel Cruise control, wiper, turning light, climate control, radio
Seat Seat position motors, occupant sensors, control panel
Engine Sensors, small motors, cooling fan motors
Door
Mirror, central ECU, mirror switch, window lift, seat control
switch, door lock
Illumination
Vehicle trim enhancement, sill plates illuminated with RGB
LED

14. References
 http://www.lin-subbus.org
 https://en.wikipedia.org/wiki/Local_Interconnect_Network