This is the description of the C/C++ for Microcontrollers API bindings for the CAN Bricklet 2.0. General information and technical specifications for the CAN Bricklet 2.0 are summarized in its hardware description.
An installation guide for the C/C++ for Microcontrollers API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 | // This example is not self-contained.
// It requires usage of the example driver specific to your platform.
// See the HAL documentation.
#include "src/bindings/hal_common.h"
#include "src/bindings/bricklet_can_v2.h"
void check(int rc, const char *msg);
void example_setup(TF_HAL *hal);
void example_loop(TF_HAL *hal);
static bool frame_readable = false;
// Callback function for frame readable callback
static void frame_readable_handler(TF_CANV2 *device, void *user_data) {
(void)device; (void)user_data; // avoid unused parameter warning
frame_readable = true;
}
static TF_CANV2 can;
void example_setup(TF_HAL *hal) {
// Create device object
check(tf_can_v2_create(&can, NULL, hal), "create device object");
// Configure transceiver for loopback mode
check(tf_can_v2_set_transceiver_configuration(&can, 1000000, 625,
TF_CAN_V2_TRANSCEIVER_MODE_LOOPBACK), "call set_transceiver_configuration");
// Register frame readable callback to function frame_readable_handler
tf_can_v2_register_frame_readable_callback(&can,
frame_readable_handler,
NULL);
// Enable frame readable callback
check(tf_can_v2_set_frame_readable_callback_configuration(&can,
true), "call set_frame_readable_callback_configuration");
// Write standard data frame with identifier 1742 and 3 bytes of data
uint8_t data[3] = {42, 23, 17};
bool success;
check(tf_can_v2_write_frame(&can, TF_CAN_V2_FRAME_TYPE_STANDARD_DATA, 1742,
data, 3, &success), "call write_frame");
if(!success)
tf_hal_printf("Failed to write frame.\n");
}
void example_loop(TF_HAL *hal) {
// Poll for callbacks
tf_hal_callback_tick(hal, 0);
if(!frame_readable)
return;
frame_readable = false;
bool success;
uint8_t frame_type;
uint32_t identifier;
uint8_t data[15];
uint8_t data_length;
// Frame readable will only trigger once, even if there are multiple frames readable, so we use a loop to
// read frames until there are none left.
check(tf_can_v2_read_frame(&can, &success, &frame_type, &identifier, data, &data_length), "read frame");
while (success) {
if(frame_type == TF_CAN_V2_FRAME_TYPE_STANDARD_DATA) {
tf_hal_printf("Frame Type: Standard Data\n");
} else if(frame_type == TF_CAN_V2_FRAME_TYPE_STANDARD_REMOTE) {
tf_hal_printf("Frame Type: Standard Remote\n");
} else if(frame_type == TF_CAN_V2_FRAME_TYPE_EXTENDED_DATA) {
tf_hal_printf("Frame Type: Extended Data\n");
} else if(frame_type == TF_CAN_V2_FRAME_TYPE_EXTENDED_REMOTE) {
tf_hal_printf("Frame Type: Extended Remote\n");
}
tf_hal_printf("Identifier: %I32u\n", identifier);
tf_hal_printf("Data (Length: %I8d):", data_length);
uint8_t i;
for (i = 0; i < data_length && i < 8; ++i) {
tf_hal_printf(" %I8d", data[i]);
}
tf_hal_printf("\n");
check(tf_can_v2_read_frame(&can, &success, &frame_type, &identifier, data, &data_length), "read frame");
}
}
|
Most functions of the C/C++ bindings for microcontrollers return an error code
(e_code
).
Possible error codes are:
(as defined in errors.h
) as well as the errors returned from
the hardware abstraction layer (HAL) that is used.
Use :cpp:func`tf_hal_strerror` (defined in the HAL's header file) to get an error string for an error code.
Data returned from the device, when a getter is called,
is handled via output parameters. These parameters are labeled with the
ret_
prefix. The bindings will not write to an output parameter if NULL or nullptr
is passed. This can be used to ignore outputs that you are not interested in.
None of the functions listed below are thread-safe. See the API bindings description for details.
tf_can_v2_create
(TF_CANV2 *can_v2, const char *uid_or_port_name, TF_HAL *hal)¶Parameters: |
|
---|---|
Returns: |
|
Creates the device object can_v2
with the optional unique device ID or port name
uid_or_port_name
and adds it to the HAL hal
:
TF_CANV2 can_v2;
tf_can_v2_create(&can_v2, NULL, &hal);
Normally uid_or_port_name
can stay NULL
. For more details about this
see section UID or Port Name.
tf_can_v2_destroy
(TF_CANV2 *can_v2)¶Parameters: |
|
---|---|
Returns: |
|
Removes the device object can_v2
from its HAL and destroys it.
The device object cannot be used anymore afterwards.
tf_can_v2_write_frame
(TF_CANV2 *can_v2, uint8_t frame_type, uint32_t identifier, const uint8_t *data, uint8_t data_length, bool *ret_success)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Writes a data or remote frame to the write queue to be transmitted over the CAN transceiver.
The Bricklet supports the standard 11-bit (CAN 2.0A) and the additional extended
29-bit (CAN 2.0B) identifiers. For standard frames the Bricklet uses bit 0 to 10
from the identifier
parameter as standard 11-bit identifier. For extended
frames the Bricklet uses bit 0 to 28 from the identifier
parameter as
extended 29-bit identifier.
The data
parameter can be up to 15 bytes long. For data frames up to 8 bytes
will be used as the actual data. The length (DLC) field in the data or remote
frame will be set to the actual length of the data
parameter. This allows
to transmit data and remote frames with excess length. For remote frames only
the length of the data
parameter is used. The actual data
bytes are
ignored.
Returns true if the frame was successfully added to the write queue. Returns
false if the frame could not be added because write queue is already full or
because the write buffer or the write backlog are configured with a size of
zero (see tf_can_v2_set_queue_configuration()
).
The write queue can overflow if frames are written to it at a higher rate
than the Bricklet can transmitted them over the CAN transceiver. This may
happen if the CAN transceiver is configured as read-only or is using a low baud
rate (see tf_can_v2_set_transceiver_configuration()
). It can also happen if the CAN
bus is congested and the frame cannot be transmitted because it constantly loses
arbitration or because the CAN transceiver is currently disabled due to a high
write error level (see tf_can_v2_get_error_log()
).
The following constants are available for this function:
For frame_type:
tf_can_v2_read_frame
(TF_CANV2 *can_v2, bool *ret_success, uint8_t *ret_frame_type, uint32_t *ret_identifier, uint8_t *ret_data, uint8_t *ret_data_length)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Tries to read the next data or remote frame from the read queue and returns it.
If a frame was successfully read, then the success
return value is set to
true and the other return values contain the frame. If the read queue is
empty and no frame could be read, then the success
return value is set to
false and the other return values contain invalid data.
The identifier
return value follows the identifier format described for
tf_can_v2_write_frame()
.
The data
return value can be up to 15 bytes long. For data frames up to the
first 8 bytes are the actual received data. All bytes after the 8th byte are
always zero and only there to indicate the length of a data or remote frame
with excess length. For remote frames the length of the data
return value
represents the requested length. The actual data
bytes are always zero.
A configurable read filter can be used to define which frames should be
received by the CAN transceiver and put into the read queue (see
tf_can_v2_set_read_filter_configuration()
).
Instead of polling with this function, you can also use callbacks. See the
tf_can_v2_set_frame_read_callback_configuration()
function and the Frame Read Low Level
callback.
The following constants are available for this function:
For ret_frame_type:
tf_can_v2_set_transceiver_configuration
(TF_CANV2 *can_v2, uint32_t baud_rate, uint16_t sample_point, uint8_t transceiver_mode)¶Parameters: |
|
---|---|
Returns: |
|
Sets the transceiver configuration for the CAN bus communication.
The CAN transceiver has three different modes:
The following constants are available for this function:
For transceiver_mode:
tf_can_v2_get_transceiver_configuration
(TF_CANV2 *can_v2, uint32_t *ret_baud_rate, uint16_t *ret_sample_point, uint8_t *ret_transceiver_mode)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the configuration as set by tf_can_v2_set_transceiver_configuration()
.
The following constants are available for this function:
For ret_transceiver_mode:
tf_can_v2_set_queue_configuration
(TF_CANV2 *can_v2, uint8_t write_buffer_size, int32_t write_buffer_timeout, uint16_t write_backlog_size, const int8_t *read_buffer_sizes, uint8_t read_buffer_sizes_length, uint16_t read_backlog_size)¶Parameters: |
|
---|---|
Returns: |
|
Sets the write and read queue configuration.
The CAN transceiver has 32 buffers in total in hardware for transmitting and receiving frames. Additionally, the Bricklet has a backlog for 768 frames in total in software. The buffers and the backlog can be freely assigned to the write and read queues.
tf_can_v2_write_frame()
writes a frame into the write backlog. The Bricklet moves
the frame from the backlog into a free write buffer. The CAN transceiver then
transmits the frame from the write buffer to the CAN bus. If there are no
write buffers (write_buffer_size
is zero) or there is no write backlog
(write_backlog_size
is zero) then no frames can be transmitted and
tf_can_v2_write_frame()
returns always false.
The CAN transceiver receives a frame from the CAN bus and stores it into a
free read buffer. The Bricklet moves the frame from the read buffer into the
read backlog. tf_can_v2_read_frame()
reads the frame from the read backlog and
returns it. If there are no read buffers (read_buffer_sizes
is empty) or
there is no read backlog (read_backlog_size
is zero) then no frames can be
received and tf_can_v2_read_frame()
returns always false.
There can be multiple read buffers, because the CAN transceiver cannot receive
data and remote frames into the same read buffer. A positive read buffer size
represents a data frame read buffer and a negative read buffer size represents
a remote frame read buffer. A read buffer size of zero is not allowed. By
default the first read buffer is configured for data frames and the second read
buffer is configured for remote frame. There can be up to 32 different read
buffers, assuming that no write buffer is used. Each read buffer has its own
filter configuration (see tf_can_v2_set_read_filter_configuration()
).
A valid queue configuration fulfills these conditions:
write_buffer_size + abs(read_buffer_size_0) + abs(read_buffer_size_1) + ... + abs(read_buffer_size_31) <= 32
write_backlog_size + read_backlog_size <= 768
The write buffer timeout has three different modes that define how a failed frame transmission should be handled:
The current content of the queues is lost when this function is called.
tf_can_v2_get_queue_configuration
(TF_CANV2 *can_v2, uint8_t *ret_write_buffer_size, int32_t *ret_write_buffer_timeout, uint16_t *ret_write_backlog_size, int8_t *ret_read_buffer_sizes, uint8_t *ret_read_buffer_sizes_length, uint16_t *ret_read_backlog_size)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the queue configuration as set by tf_can_v2_set_queue_configuration()
.
tf_can_v2_set_read_filter_configuration
(TF_CANV2 *can_v2, uint8_t buffer_index, uint8_t filter_mode, uint32_t filter_mask, uint32_t filter_identifier)¶Parameters: |
|
---|---|
Returns: |
|
Set the read filter configuration for the given read buffer index. This can be used to define which frames should be received by the CAN transceiver and put into the read buffer.
The read filter has four different modes that define if and how the filter mask and the filter identifier are applied:
The filter mask and filter identifier are used as bit masks. Their usage depends on the mode:
The filter mask and filter identifier are applied in this way: The filter mask is used to select the frame identifier bits that should be compared to the corresponding filter identifier bits. All unselected bits are automatically accepted. All selected bits have to match the filter identifier to be accepted. If all bits for the selected mode are accepted then the frame is accepted and is added to the read buffer.
Filter Mask Bit | Filter Identifier Bit | Frame Identifier Bit | Result |
---|---|---|---|
0 | X | X | Accept |
1 | 0 | 0 | Accept |
1 | 0 | 1 | Reject |
1 | 1 | 0 | Reject |
1 | 1 | 1 | Accept |
For example, to receive standard frames with identifier 0x123 only, the mode can be set to Match-Standard-Only with 0x7FF as mask and 0x123 as identifier. The mask of 0x7FF selects all 11 identifier bits for matching so that the identifier has to be exactly 0x123 to be accepted.
To accept identifier 0x123 and identifier 0x456 at the same time, just set filter 2 to 0x456 and keep mask and filter 1 unchanged.
There can be up to 32 different read filters configured at the same time,
because there can be up to 32 read buffer (see tf_can_v2_set_queue_configuration()
).
The default mode is accept-all for all read buffers.
The following constants are available for this function:
For filter_mode:
tf_can_v2_get_read_filter_configuration
(TF_CANV2 *can_v2, uint8_t buffer_index, uint8_t *ret_filter_mode, uint32_t *ret_filter_mask, uint32_t *ret_filter_identifier)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the read filter configuration as set by tf_can_v2_set_read_filter_configuration()
.
The following constants are available for this function:
For ret_filter_mode:
tf_can_v2_get_error_log
(TF_CANV2 *can_v2, uint8_t *ret_transceiver_state, uint8_t *ret_transceiver_write_error_level, uint8_t *ret_transceiver_read_error_level, uint32_t *ret_transceiver_stuffing_error_count, uint32_t *ret_transceiver_format_error_count, uint32_t *ret_transceiver_ack_error_count, uint32_t *ret_transceiver_bit1_error_count, uint32_t *ret_transceiver_bit0_error_count, uint32_t *ret_transceiver_crc_error_count, uint32_t *ret_write_buffer_timeout_error_count, uint32_t *ret_read_buffer_overflow_error_count, bool *ret_read_buffer_overflow_error_occurred, uint8_t *ret_read_buffer_overflow_error_occurred_length, uint32_t *ret_read_backlog_overflow_error_count)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns information about different kinds of errors.
The write and read error levels indicate the current level of stuffing, form, acknowledgement, bit and checksum errors during CAN bus write and read operations. For each of this error kinds there is also an individual counter.
When the write error level extends 255 then the CAN transceiver gets disabled and no frames can be transmitted or received anymore. The CAN transceiver will automatically be activated again after the CAN bus is idle for a while.
The write buffer timeout, read buffer and backlog overflow counts represents the number of these errors:
tf_can_v2_set_queue_configuration()
).tf_can_v2_set_read_filter_configuration()
) can help to reduce the amount of
received frames. This count is not exact, but a lower bound, because the
Bricklet might not able detect all overflows if they occur in rapid succession.tf_can_v2_read_frame()
function. Using the Frame Read Low Level
callback ensures that the read backlog
can not overflow.The read buffer overflow counter counts the overflows of all configured read
buffers. Which read buffer exactly suffered from an overflow can be figured
out from the read buffer overflow occurrence list
(read_buffer_overflow_error_occurred
). Reading the error log clears the
occurence list.
The following constants are available for this function:
For ret_transceiver_state:
tf_can_v2_set_communication_led_config
(TF_CANV2 *can_v2, uint8_t config)¶Parameters: |
|
---|---|
Returns: |
|
Sets the communication LED configuration. By default the LED shows CAN-Bus traffic, it flickers once for every 40 transmitted or received frames.
You can also turn the LED permanently on/off or show a heartbeat.
If the Bricklet is in bootloader mode, the LED is off.
The following constants are available for this function:
For config:
tf_can_v2_get_communication_led_config
(TF_CANV2 *can_v2, uint8_t *ret_config)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the configuration as set by tf_can_v2_set_communication_led_config()
The following constants are available for this function:
For ret_config:
tf_can_v2_set_error_led_config
(TF_CANV2 *can_v2, uint8_t config)¶Parameters: |
|
---|---|
Returns: |
|
Sets the error LED configuration.
By default (show-transceiver-state) the error LED turns on if the CAN
transceiver is passive or disabled state (see tf_can_v2_get_error_log()
). If
the CAN transceiver is in active state the LED turns off.
If the LED is configured as show-error then the error LED turns on if any error occurs. If you call this function with the show-error option again, the LED will turn off until the next error occurs.
You can also turn the LED permanently on/off or show a heartbeat.
If the Bricklet is in bootloader mode, the LED is off.
The following constants are available for this function:
For config:
tf_can_v2_get_error_led_config
(TF_CANV2 *can_v2, uint8_t *ret_config)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the configuration as set by tf_can_v2_set_error_led_config()
.
The following constants are available for this function:
For ret_config:
tf_can_v2_get_spitfp_error_count
(TF_CANV2 *can_v2, uint32_t *ret_error_count_ack_checksum, uint32_t *ret_error_count_message_checksum, uint32_t *ret_error_count_frame, uint32_t *ret_error_count_overflow)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the error count for the communication between Brick and Bricklet.
The errors are divided into
The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.
tf_can_v2_set_status_led_config
(TF_CANV2 *can_v2, uint8_t config)¶Parameters: |
|
---|---|
Returns: |
|
Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.
You can also turn the LED permanently on/off or show a heartbeat.
If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.
The following constants are available for this function:
For config:
tf_can_v2_get_status_led_config
(TF_CANV2 *can_v2, uint8_t *ret_config)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the configuration as set by tf_can_v2_set_status_led_config()
The following constants are available for this function:
For ret_config:
tf_can_v2_get_chip_temperature
(TF_CANV2 *can_v2, int16_t *ret_temperature)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the temperature as measured inside the microcontroller. The value returned is not the ambient temperature!
The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.
tf_can_v2_reset
(TF_CANV2 *can_v2)¶Parameters: |
|
---|---|
Returns: |
|
Calling this function will reset the Bricklet. All configurations will be lost.
After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!
tf_can_v2_get_identity
(TF_CANV2 *can_v2, char ret_uid[8], char ret_connected_uid[8], char *ret_position, uint8_t ret_hardware_version[3], uint8_t ret_firmware_version[3], uint16_t *ret_device_identifier)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.
The position can be 'a', 'b', 'c', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.
The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.
tf_can_v2_set_frame_read_callback_configuration
(TF_CANV2 *can_v2, bool enabled)¶Parameters: |
|
---|---|
Returns: |
|
Enables and disables the Frame Read Low Level
callback.
By default the callback is disabled. Enabling this callback will disable the Frame Readable
callback.
tf_can_v2_get_frame_read_callback_configuration
(TF_CANV2 *can_v2, bool *ret_enabled)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns true if the Frame Read Low Level
callback is enabled, false otherwise.
tf_can_v2_set_frame_readable_callback_configuration
(TF_CANV2 *can_v2, bool enabled)¶Parameters: |
|
---|---|
Returns: |
|
Enables and disables the Frame Readable
callback.
By default the callback is disabled. Enabling this callback will disable the Frame Read Low Level
callback.
New in version 2.0.3 (Plugin).
tf_can_v2_get_frame_readable_callback_configuration
(TF_CANV2 *can_v2, bool *ret_enabled)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns true if the Frame Readable
callback is enabled, false otherwise.
New in version 2.0.3 (Plugin).
tf_can_v2_set_error_occurred_callback_configuration
(TF_CANV2 *can_v2, bool enabled)¶Parameters: |
|
---|---|
Returns: |
|
Enables and disables the Error Occurred
callback.
By default the callback is disabled.
New in version 2.0.3 (Plugin).
tf_can_v2_get_error_occurred_callback_configuration
(TF_CANV2 *can_v2, bool *ret_enabled)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns true if the Error Occurred
callback is enabled, false otherwise.
New in version 2.0.3 (Plugin).
Callbacks can be registered to receive time critical or recurring data from the
device. The registration is done with the corresponding tf_can_v2_register_*_callback
function.
The user_data
passed to the registration function as well as the device that triggered the callback are
passed to the registered callback handler.
Only one handler can be registered to a callback at the same time.
To deregister a callback, call the tf_can_v2_register_*_callback
function
with NULL as handler.
Note
Using callbacks for recurring events is preferred compared to using getters. Polling for a callback requires writing one byte only. See here Optimizing Performance.
Warning
Calling bindings function from inside a callback handler is not allowed. See here Thread safety.
tf_can_v2_register_frame_read_low_level_callback
(TF_CANV2 *can_v2, TF_CANV2_FrameReadLowLevelHandler handler, void *user_data)¶void handler(TF_CANV2 *can_v2, uint8_t frame_type, uint32_t identifier, uint8_t data_length, uint8_t data_data[15], void *user_data)
Callback Parameters: |
|
---|
This callback is triggered if a data or remote frame was received by the CAN transceiver.
The identifier
return value follows the identifier format described for
tf_can_v2_write_frame()
.
For details on the data
return value see tf_can_v2_read_frame()
.
A configurable read filter can be used to define which frames should be
received by the CAN transceiver and put into the read queue (see
tf_can_v2_set_read_filter_configuration()
).
To enable this callback, use tf_can_v2_set_frame_read_callback_configuration()
.
The following constants are available for this function:
For frame_type:
tf_can_v2_register_frame_readable_callback
(TF_CANV2 *can_v2, TF_CANV2_FrameReadableHandler handler, void *user_data)¶void handler(TF_CANV2 *can_v2, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered if a data or remote frame was received by the CAN
transceiver. The received frame can be read with tf_can_v2_read_frame()
.
If additional frames are received, but tf_can_v2_read_frame()
was not called yet, the callback
will not trigger again.
A configurable read filter can be used to define which frames should be
received by the CAN transceiver and put into the read queue (see
tf_can_v2_set_read_filter_configuration()
).
To enable this callback, use tf_can_v2_set_frame_readable_callback_configuration()
.
New in version 2.0.3 (Plugin).
tf_can_v2_register_error_occurred_callback
(TF_CANV2 *can_v2, TF_CANV2_ErrorOccurredHandler handler, void *user_data)¶void handler(TF_CANV2 *can_v2, void *user_data)
Callback Parameters: |
|
---|
This callback is triggered if any error occurred while writing, reading or transmitting CAN frames.
The callback is only triggered once until tf_can_v2_get_error_log()
is called. That function will return
details abount the error(s) occurred.
To enable this callback, use tf_can_v2_set_error_occurred_callback_configuration()
.
New in version 2.0.3 (Plugin).
Virtual functions don't communicate with the device itself, but operate only on the API bindings device object.
tf_can_v2_get_response_expected
(TF_CANV2 *can_v2, uint8_t function_id, bool *ret_response_expected)¶Parameters: |
|
---|---|
Output Parameters: |
|
Returns: |
|
Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.
For getter functions this is enabled by default and cannot be disabled,
because those functions will always send a response. For callback configuration
functions it is enabled by default too, but can be disabled by
tf_can_v2_set_response_expected()
. For setter functions it is disabled by default
and can be enabled.
Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.
The following constants are available for this function:
For function_id:
tf_can_v2_set_response_expected
(TF_CANV2 *can_v2, uint8_t function_id, bool response_expected)¶Parameters: |
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Returns: |
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Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.
Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.
The following constants are available for this function:
For function_id:
tf_can_v2_set_response_expected_all
(TF_CANV2 *can_v2, bool response_expected)¶Parameters: |
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Returns: |
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Changes the response expected flag for all setter and callback configuration functions of this device at once.
Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.
tf_can_v2_set_bootloader_mode
(TF_CANV2 *can_v2, uint8_t mode, uint8_t *ret_status)¶Parameters: |
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Output Parameters: |
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Returns: |
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Sets the bootloader mode and returns the status after the requested mode change was instigated.
You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.
This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.
The following constants are available for this function:
For mode:
For ret_status:
tf_can_v2_get_bootloader_mode
(TF_CANV2 *can_v2, uint8_t *ret_mode)¶Parameters: |
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Output Parameters: |
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Returns: |
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Returns the current bootloader mode, see tf_can_v2_set_bootloader_mode()
.
The following constants are available for this function:
For ret_mode:
tf_can_v2_set_write_firmware_pointer
(TF_CANV2 *can_v2, uint32_t pointer)¶Parameters: |
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Returns: |
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Sets the firmware pointer for tf_can_v2_write_firmware()
. The pointer has
to be increased by chunks of size 64. The data is written to flash
every 4 chunks (which equals to one page of size 256).
This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.
tf_can_v2_write_firmware
(TF_CANV2 *can_v2, const uint8_t data[64], uint8_t *ret_status)¶Parameters: |
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Output Parameters: |
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Returns: |
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Writes 64 Bytes of firmware at the position as written by
tf_can_v2_set_write_firmware_pointer()
before. The firmware is written
to flash every 4 chunks.
You can only write firmware in bootloader mode.
This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.
tf_can_v2_write_uid
(TF_CANV2 *can_v2, uint32_t uid)¶Parameters: |
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Returns: |
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Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.
We recommend that you use Brick Viewer to change the UID.
tf_can_v2_read_uid
(TF_CANV2 *can_v2, uint32_t *ret_uid)¶Parameters: |
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Output Parameters: |
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Returns: |
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Returns the current UID as an integer. Encode as Base58 to get the usual string version.
TF_CAN_V2_DEVICE_IDENTIFIER
¶This constant is used to identify a CAN Bricklet 2.0.
The functions tf_can_v2_get_identity()
and tf_hal_get_device_info()
have a device_identifier
output parameter to specify
the Brick's or Bricklet's type.
TF_CAN_V2_DEVICE_DISPLAY_NAME
¶This constant represents the human readable name of a CAN Bricklet 2.0.