Difference between revisions of "CAN Bus"
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== CAN Bus Messages == | == CAN Bus Messages == | ||
| − | The following table gives an overview over all messages present on the CAN bus. Further detailed descriptions can be found below. | + | The following table gives an overview over all messages present on the CAN bus. Further detailed descriptions can be found below. The ID equals the CAN id that this message is transferred with, the Symbolic Constant is the name by which the corresponding ID is defined in the sources. |
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Revision as of 15:50, 4 August 2010
Contents
CAN Bus Configuration
The communication in the Concept Car is implemented via a high-speed (1Mbit/s) CAN-Bus (Controller-area network), featuring a message based protocol. Each message has a message identifier to distinguish between different message types. CAN standard 2.0A is applied, so the message identifiers are 11 bits wide, allowing 2048 distinct messages. Further details about the CAN-Bus can be found in [ZS08].
In the ConceptCar, only messages with the length of 4 Bytes, which are interpreted as an unsigned integer number, are used. How the message data has to be interpreted depends only on the message identifier, further details are given in the next section.
CAN Bus Messages
The following table gives an overview over all messages present on the CAN bus. Further detailed descriptions can be found below. The ID equals the CAN id that this message is transferred with, the Symbolic Constant is the name by which the corresponding ID is defined in the sources.
| ID (hex) | ID | Symbolic constant | Short Description | Source |
|---|---|---|---|---|
| 0x008 | 8 | CANID_WHEELSPEED_FL | Rotation Speed Front Left Wheel | Sensorboard Throttle |
| 0x009 | 9 | CANID_WHEELSPEED_FR | Rotation Speed Front Right Wheel | Sensorboard Steering |
| 0x00a | 10 | CANID_WHEELSPEED_RL | Rotation Speed Rear Left Wheel | Sensorboard Steering |
| 0x00b | 11 | CANID_WHEELSPEED_RR | Rotation Speed Rear Right Wheel | Sensorboard Throttle |
| 0x00d | 13 | CANID_VOLTAGE | Voltage of the electrical System | Sensorboard Inertial |
| 0x00e | 14 | CANID_RESETCOUNTER | Number of Resets since last ECU flashing | Sensorboard Inertial |
| 0x010 | 16 | CANID_INERTIAL_AX | Longitudinal Acceleration | Sensorboard Inertial |
| 0x011 | 17 | CANID_INERTIAL_AY | Lateral Acceleration | Sensorboard Inertial |
| 0x012 | 18 | CANID_ROTATION | Rotation Speed Car | Sensorboard Inertial |
| 0x020 | 32 | CANID_SELECTJUMPER | Actorboard Source Selection | Actorboard |
| 0x022 | 34 | CANID_THROTTLE | Throttle from SensorBoard | Sensorboard Throttle |
| 0x122 | 290 | CANID_THROTTLE_ARM7 | Throttle from ARM7 Board | ARM7 Board |
| 0x023 | 35 | CANID_BRAKEFL | Front Left Brake Signal from SensorBoard | Sensorboard Throttle |
| 0x123 | 291 | CANID_BRAKEFL_ARM7 | Front Left Brake Signal from ARM7 Board | ARM7 Board |
| 0x024 | 36 | CANID_BRAKEFR | Front Right Brake Signal from SensorBoard | Sensorboard Throttle |
| 0x124 | 292 | CANID_BRAKEFR_ARM7 | Front Right Brake Signal from ARM7 Board | ARM7 Board |
| 0x025 | 37 | CANID_STEERING | Steering from SensorBoard | Sensorboard Steering |
| 0x125 | 293 | CANID_STEERING_ARM7 | Steering from ARM7 Board | ARM7 Board |
| 0x030 | 48 | CANID_DISTANCE | Front Distance (Ultrasonic Sensor) | Sensorboard Distance |
| 0x400 | 1024 | CANID_ERROR | Error Message | ALL |
CANID_WHEELSPEED
| CAN ID | 0x8 (FL), 0x9 (FR), 0xa (RL) and 0xb (RR) |
| Interval | 50ms |
| Producer | Sensorboard Steering (0x9 and 0xa) and Sensorboard Throttle (0x8 and 0xb) |
| Consumer | Not yet specified |
| Semantics | Todo |
CANID_VOLTAGE
| CAN ID | 0xd |
| Interval | 200ms |
| Producer | Sensorboard Inertial |
| Consumer | Not yet specified |
| Semantics | The voltage of the battery driving the electrical system.
|
CANID_RESETCOUNTER
| CAN ID | 0xe |
| Interval | Once at boot time of the Sensorboard Inertial |
| Producer | Sensorboard Inertial |
| Consumer | Not yet specified |
| Semantics | An integer with the number of times the Sensorboard Inertial has been booted. |
CANID_INERTIAL
| CAN ID | 0x10 (longitudinal) and 0x11 (lateral) |
| Interval | 20ms |
| Producer | Sensorboard Inertial |
| Consumer | Not yet specified |
| Semantics | The longitudinal and lateral acceleration of the car, measured with the ADIS16006 accelerometer.
|
CANID_ROTATION
| CAN ID | 0x12 |
| Interval | 20ms |
| Producer | Sensorboard Inertial |
| Consumer | Not yet specified |
| Semantics | The rotation speed of the car around its axis, measured with the ADIS16100 gyroscope.
|
CANID_SELECTJUMPER
| CAN ID | 0x20 |
| Interval | 1s, and sent when switch on Actorboard has been toggled. |
| Producer | Actorboard |
| Consumer | Not yet specified |
| Semantics | Binary value, announces which source the Actorboard is configured to use.
|
CANID_THROTTLE
| CAN ID | 0x22 and 0x122 |
| Interval | ~20ms, depends on remote transceiver (currently 17ms) |
| Producer | Sensorboard Throttle (0x22) and ARM7 Board (0x122) |
| Consumer | Actorboard |
| Semantics | The relative value of the throttle. Ranges from 0 (don't accelerate) to 1000 (maximum acceleration) File:Throttle conversion function.png |
CANID_BRAKE
| CAN ID | 0x23 and 0x123 (left), 0x24 and 0x124 (right) |
| Interval | ~20ms, depends on remote transceiver (currently 17ms) |
| Producer | Sensorboard Throttle (0x23 and 0x24) and ARM7 Board (0x123 and 0x124) |
| Consumer | Actorboard |
| Semantics | The relative value of the brake. Two distinct signals exist for brakes on the left and right side; currently they both carry the same value. Ranges from 0 (brakes released) to 1000 (full break) |
CANID_STEERING
| CAN ID | 0x25 and 0x125 |
| Interval | ~20ms, depends on remote transceiver (currently 17ms) |
| Producer | Sensorboard Steering (0x25) and ARM7 Board (0x125) |
| Consumer | Actorboard |
| Semantics | The desired value for the steering in 0.1° steps. Ranges from 0 (steering 30° left) over 300 (steering straight) to 600 (steering 30° right)
|
CANID_DISTANCE
| CAN ID | 0x30 |
| Interval | 10ms - 70ms, depends on distance (round trip time of sonic pulse). The farther the target, the longer it takes. |
| Producer | Sensorboard Distance |
| Consumer | Not yet specified |
| Semantics | An integer value, holding the distance to the next obstacle detected ahead in centimeters. Detector unit is the supersonic sensor SRF02.
|
CANID_ERROR
| CAN ID | 0x400 |
| Interval | 50ms |
| Producer | all |
| Consumer | Not yet specified |
| Semantics | Todo |
