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Aesop2 - Vehicle "flight recorder"

The Aesop2 is an inexpensive vehicle "flight recorder" platform supporting CAN and J1850VPW interfaces. Data is aquired from the vehicle and saved to an inexpensive MMC card "disk". An optional ethernet connection can be used to retrieve MMC data and/or communicate with the vehicle interfaces.

Two status LEDs indicate the operation state of the box and a push button allows the user to "mark" the data stream while data is being recorded.

Based on a PIC microprocessor, the platform can communcicate with a CAN bus or J1850VPW vehicle interface via a standard OBD-II J1962 connector. When in data collection mode a configuration file is read from the MMC card and the recorded data is written back to the MMC card. Data is saved using a standard DOS file system making recovery of the data easy using a Windows based PC.

MMC cards are available from 16-64mb, providing space for hours of recorded data.

Windows command-line programs are provided to create the setup file and interpret the recorded data file.

Optionally the ethernet interface can used to drive the vehicle interfaces or to read data from the MMC card.

picture of Aesop enclosure
picture of Aesop circuit board

















The Aesop platform has the following capabilities:

  • CAN 1.2A, 2.0A/B
  • J1850 VPW
  • Chrysler SCI
  • MMC card slot, DOS FAT16 file system
  • 10Mb 10baseT Ethernet
  • Powered by vehicle interface
  • Status LED's
  • Push-button allows user to mark data stream



Technical details:

PIC18F458 microprocessor with Cirrus/Crystal CS8900A ethernet chip. Includes interfaces for CAN, J1850 VPW and SCI.

  • The PIC18F458 has on-chip flash which contains the communication firmware.

  • CAN 1.2A, 2.0A, 2.0B. Uses Microchip MCP2551 transceiver - meets or exceeds ISO11898-2 spec (ISO11898-2 high-speed CAN communication in road vehicles)

  • J1850 interface uses a Motorola MC33390 transceiver. The VPW protocol is implemented in firmware.

  • MMC socket. Files are read and written using DOS FAT16 format, compatible with Windows operating system. Cards are supportted from 16Mbytes to 64Mbytes. A setup file is read from the MMC card which contains the protocol commands to collect data.

  • The firmware implements TCP/IP protocol and allows TCP connections to the board for sending and receiving mid-level protocol messages. Supports TCP, UDP, DHCP, IP V4, ARP.

  • Powered by 7-15VDC @ 200ma. The PCB has an on-board regulator which steps the voltage down to 5vdc for the internal logic.

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