Difference between revisions of "AVC-LAN"

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(Custom(aka Hacked))
Line 32: Line 32:
  
 
=== Custom(aka Hacked) ===
 
=== Custom(aka Hacked) ===
 +
* [[http://www.softservice.com.pl/corolla/avc/ Marcin Slonicki]] AVC-Lan MP3 player
 +
** ATmega8 is clocked at 14.7456 MHz with an external crystal
 +
** PCA82C250 CAN bus driver is used to drive the IEBus
 +
** LM239 comparator is required on top of the PCA82C250 to read from the IEBus

Revision as of 00:12, 30 November 2009

Introduction

The AVC-LAN is part of the Body Electrical System Control and manages all audio and video related functions. The audio bus is described in Toyota's own words as follows:

AVC-LAN consist of audio visual systems such as the multi-display, navigation ECU, radio and
player, stereo component amplifier and gateway ECU. Gateway ECU has communication
circuit to correspond with different types of communication data. Different types of
communication data can be shared among communication parts after it goes through gateway
ECU (System Circuits: AVC-LAN Bus, “Prius Wiring Diagram” 80).

The system itself can be considered a subset of the IEBus Standard, which was delevoped by NEC electronics for automotive use. It is slightly faster than the BEAN bus and has more data per command, but is still much slower than CAN, since realtime speeds are not required.

Connections

Iebus-connections.gif

Waveform

Iebus-waveform.jpg

  • Prep 7uS
  • Sync 20uS
  • Data 13uS

Protocol

Iebus-message.jpg

(Jeremiah J. Flerchinger Source)

Hardware

Specific

  • HA12240 Differential Transceiver
  • NEC uPD6708 IEBus (Inter Equipment Bus) PROTOCOL CONTROL LSI

Custom(aka Hacked)

  • [Marcin Slonicki] AVC-Lan MP3 player
    • ATmega8 is clocked at 14.7456 MHz with an external crystal
    • PCA82C250 CAN bus driver is used to drive the IEBus
    • LM239 comparator is required on top of the PCA82C250 to read from the IEBus