CanBus
robodyno.interfaces.can_bus
This module provides CAN bus interface for robodyno devices.
Examples:
>>> from robodyno.interfaces import CanBus
>>> can_bus = CanBus()
>>> can_bus.send(0x10, 0x0e, 'fee', 50, 0.02, 0.1)
>>> can_bus.get(0x10, 0x0d, 'fee')
(50.0, 0.0200042724609375, 0.0999755859375)
>>> can_bus.subscribe(callback, 0x10, 0x02)
>>> can_bus.unsubscribe(callback, 0x10, 0x02)
>>> can_bus.disconnect()
CanBus
Bases: object
CAN bus interface for robodyno devices.
This class provides CAN bus interface for robodyno devices. It supports sending and receiving data from CAN bus. It also supports subscribing data from CAN bus.
A thread is created to receive data from CAN bus. When a device ID and a command ID is subscribed, the callback function will be called when the corresponding data is received.
__init__(bitrate=1000000, channel='can0', connect=True)
Initialize CAN bus interface with given channel and bitrate.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
bitrate |
int
|
CAN bus bitrate, e.g. 1000000. |
1000000
|
channel |
str
|
CAN bus channel name, e.g. 'can0'. |
'can0'
|
connect |
bool
|
Whether to connect to CAN bus. |
True
|
Raises:
| Type | Description |
|---|---|
NotImplementedError
|
If the platform is not supported. |
connect()
Connect to CAN bus.
disconnect()
Disconnect from CAN bus.
send(device_id, cmd_id, fmt, *args)
Send data to CAN bus.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
device_id |
int
|
Device ID. |
required |
cmd_id |
int
|
Command ID. |
required |
fmt |
str
|
Format string for packing data. See struct module for details. |
required |
*args |
Data to be sent. |
()
|
get(device_id, cmd_id, fmt, timeout=None)
Get data from CAN bus.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
device_id |
int
|
Device ID. |
required |
cmd_id |
int
|
Command ID. |
required |
fmt |
str
|
Format string for unpacking data. See struct module for details. |
required |
timeout |
float
|
Timeout for receiving data. |
None
|
Returns:
| Type | Description |
|---|---|
tuple
|
Received data. |
Raises:
| Type | Description |
|---|---|
TimeoutError
|
If timeout. |
subscribe(callback, device_id=-1, cmd_id=-1)
Subscribe data from CAN bus.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
callback |
func
|
Callback function. The function should accept four arguments,
e.g. |
required |
device_id |
int
|
Device ID. -1 for all devices. |
-1
|
cmd_id |
int
|
Command ID. -1 for all commands. |
-1
|
unsubscribe(callback, device_id=-1, cmd_id=-1)
Unsubscribe data from CAN bus.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
callback |
func
|
Callback function. |
required |
device_id |
int
|
Device ID. -1 for all devices. |
-1
|
cmd_id |
int
|
Command ID. -1 for all commands. |
-1
|