This is the description of the C/C++ API bindings for the Piezo Speaker Bricklet 2.0. General information and technical specifications for the Piezo Speaker Bricklet 2.0 are summarized in its hardware description.
An installation guide for the C/C++ API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
1#include <stdio.h>
2
3#include "ip_connection.h"
4#include "bricklet_piezo_speaker_v2.h"
5
6#define HOST "localhost"
7#define PORT 4223
8#define UID "XYZ" // Change XYZ to the UID of your Piezo Speaker Bricklet 2.0
9
10int main(void) {
11 // Create IP connection
12 IPConnection ipcon;
13 ipcon_create(&ipcon);
14
15 // Create device object
16 PiezoSpeakerV2 ps;
17 piezo_speaker_v2_create(&ps, UID, &ipcon);
18
19 // Connect to brickd
20 if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
21 fprintf(stderr, "Could not connect\n");
22 return 1;
23 }
24 // Don't use device before ipcon is connected
25
26 // 10 seconds of loud annoying fast alarm
27 piezo_speaker_v2_set_alarm(&ps, 800, 2000, 10, 1, 10, 10000);
28
29 printf("Press key to exit\n");
30 getchar();
31 piezo_speaker_v2_destroy(&ps);
32 ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
33 return 0;
34}
1#include <stdio.h>
2
3#include "ip_connection.h"
4#include "bricklet_piezo_speaker_v2.h"
5
6#define HOST "localhost"
7#define PORT 4223
8#define UID "XYZ" // Change XYZ to the UID of your Piezo Speaker Bricklet 2.0
9
10int main(void) {
11 // Create IP connection
12 IPConnection ipcon;
13 ipcon_create(&ipcon);
14
15 // Create device object
16 PiezoSpeakerV2 ps;
17 piezo_speaker_v2_create(&ps, UID, &ipcon);
18
19 // Connect to brickd
20 if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
21 fprintf(stderr, "Could not connect\n");
22 return 1;
23 }
24 // Don't use device before ipcon is connected
25
26 // Make 2 second beep with a frequency of 1kHz
27 piezo_speaker_v2_set_beep(&ps, 1000, 0, 2000);
28
29 printf("Press key to exit\n");
30 getchar();
31 piezo_speaker_v2_destroy(&ps);
32 ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
33 return 0;
34}
Most functions of the C/C++ bindings return an error code (e_code).
Data returned from the device, when a getter is called,
is handled via output parameters. These parameters are labeled with the
ret_ prefix.
Possible error codes are:
E_OK = 0
E_TIMEOUT = -1
E_NO_STREAM_SOCKET = -2
E_HOSTNAME_INVALID = -3
E_NO_CONNECT = -4
E_NO_THREAD = -5
E_NOT_ADDED = -6 (unused since C/C++ bindings version 2.0.0)
E_ALREADY_CONNECTED = -7
E_NOT_CONNECTED = -8
E_INVALID_PARAMETER = -9
E_NOT_SUPPORTED = -10
E_UNKNOWN_ERROR_CODE = -11
E_STREAM_OUT_OF_SYNC = -12
E_INVALID_UID = -13
E_NON_ASCII_CHAR_IN_SECRET = -14
E_WRONG_DEVICE_TYPE = -15
E_DEVICE_REPLACED = -16
E_WRONG_RESPONSE_LENGTH = -17
as defined in ip_connection.h.
All functions listed below are thread-safe.
| Parameters: |
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Creates the device object piezo_speaker_v2 with the unique device ID uid and adds
it to the IPConnection ipcon:
PiezoSpeakerV2 piezo_speaker_v2;
piezo_speaker_v2_create(&piezo_speaker_v2, "YOUR_DEVICE_UID", &ipcon);
This device object can be used after the IP connection has been connected.
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Removes the device object piezo_speaker_v2 from its IPConnection and destroys it.
The device object cannot be used anymore afterwards.
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Beeps with the given frequency and volume for the duration.
A duration of 0 stops the current beep if any is ongoing. A duration of 4294967295 results in an infinite beep.
The following constants are available for this function:
For duration:
PIEZO_SPEAKER_V2_BEEP_DURATION_OFF = 0
PIEZO_SPEAKER_V2_BEEP_DURATION_INFINITE = 4294967295
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Returns the last beep settings as set by piezo_speaker_v2_set_beep(). If a beep is currently
running it also returns the remaining duration of the beep.
If the frequency or volume is updated during a beep (with piezo_speaker_v2_update_frequency()
or piezo_speaker_v2_update_volume()) this function returns the updated value.
The following constants are available for this function:
For ret_duration:
PIEZO_SPEAKER_V2_BEEP_DURATION_OFF = 0
PIEZO_SPEAKER_V2_BEEP_DURATION_INFINITE = 4294967295
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Creates an alarm (a tone that goes back and force between two specified frequencies).
The following parameters can be set:
Start Frequency: Start frequency of the alarm.
End Frequency: End frequency of the alarm.
Step Size: Size of one step of the sweep between the start/end frequencies.
Step Delay: Delay between two steps (duration of time that one tone is used in a sweep).
Duration: Duration of the alarm.
A duration of 0 stops the current alarm if any is ongoing. A duration of 4294967295 results in an infinite alarm.
Below you can find two sets of example settings that you can try out. You can use these as a starting point to find an alarm signal that suits your application.
Example 1: 10 seconds of loud annoying fast alarm
Start Frequency = 800
End Frequency = 2000
Step Size = 10
Step Delay = 1
Volume = 10
Duration = 10000
Example 2: 10 seconds of soft siren sound with slow build-up
Start Frequency = 250
End Frequency = 750
Step Size = 1
Step Delay = 5
Volume = 0
Duration = 10000
The following conditions must be met:
Start Frequency: has to be smaller than end frequency
End Frequency: has to be bigger than start frequency
Step Size: has to be small enough to fit into the frequency range
Step Delay: has to be small enough to fit into the duration
The following constants are available for this function:
For duration:
PIEZO_SPEAKER_V2_ALARM_DURATION_OFF = 0
PIEZO_SPEAKER_V2_ALARM_DURATION_INFINITE = 4294967295
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Returns the last alarm settings as set by piezo_speaker_v2_set_alarm(). If an alarm is currently
running it also returns the remaining duration of the alarm as well as the
current frequency of the alarm.
If the volume is updated during an alarm (with piezo_speaker_v2_update_volume())
this function returns the updated value.
The following constants are available for this function:
For ret_duration:
PIEZO_SPEAKER_V2_ALARM_DURATION_OFF = 0
PIEZO_SPEAKER_V2_ALARM_DURATION_INFINITE = 4294967295
For ret_duration_remaining:
PIEZO_SPEAKER_V2_ALARM_DURATION_OFF = 0
PIEZO_SPEAKER_V2_ALARM_DURATION_INFINITE = 4294967295
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Updates the volume of an ongoing beep or alarm.
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Updates the frequency of an ongoing beep.
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Returns the error count for the communication between Brick and Bricklet.
The errors are divided into
ACK checksum errors,
message checksum errors,
framing errors and
overflow errors.
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.
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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:
PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_OFF = 0
PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_ON = 1
PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
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Returns the configuration as set by piezo_speaker_v2_set_status_led_config()
The following constants are available for this function:
For ret_config:
PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_OFF = 0
PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_ON = 1
PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
PIEZO_SPEAKER_V2_STATUS_LED_CONFIG_SHOW_STATUS = 3
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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.
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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!
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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.
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Registers the given function with the given callback_id. The
user_data will be passed as the last parameter to the function.
The available callback IDs with corresponding function signatures are listed below.
Callbacks can be registered to receive time critical or recurring data from the
device. The registration is done with the piezo_speaker_v2_register_callback() function:
void my_callback(int value, void *user_data) { printf("Value: %d\n", value); } piezo_speaker_v2_register_callback(&piezo_speaker_v2, PIEZO_SPEAKER_V2_CALLBACK_EXAMPLE, (void (*)(void))my_callback, NULL);
The available constants with corresponding function signatures are described below.
Note
Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.
void callback(void *user_data)
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This callback is triggered if a beep set by piezo_speaker_v2_set_beep() is finished
void callback(void *user_data)
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This callback is triggered if a alarm set by piezo_speaker_v2_set_alarm() is finished
Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.
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Returns the version of the API definition implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.
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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
piezo_speaker_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:
PIEZO_SPEAKER_V2_FUNCTION_SET_BEEP = 1
PIEZO_SPEAKER_V2_FUNCTION_SET_ALARM = 3
PIEZO_SPEAKER_V2_FUNCTION_UPDATE_VOLUME = 5
PIEZO_SPEAKER_V2_FUNCTION_UPDATE_FREQUENCY = 6
PIEZO_SPEAKER_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
PIEZO_SPEAKER_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
PIEZO_SPEAKER_V2_FUNCTION_RESET = 243
PIEZO_SPEAKER_V2_FUNCTION_WRITE_UID = 248
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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:
PIEZO_SPEAKER_V2_FUNCTION_SET_BEEP = 1
PIEZO_SPEAKER_V2_FUNCTION_SET_ALARM = 3
PIEZO_SPEAKER_V2_FUNCTION_UPDATE_VOLUME = 5
PIEZO_SPEAKER_V2_FUNCTION_UPDATE_FREQUENCY = 6
PIEZO_SPEAKER_V2_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
PIEZO_SPEAKER_V2_FUNCTION_SET_STATUS_LED_CONFIG = 239
PIEZO_SPEAKER_V2_FUNCTION_RESET = 243
PIEZO_SPEAKER_V2_FUNCTION_WRITE_UID = 248
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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.
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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:
PIEZO_SPEAKER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE = 1
PIEZO_SPEAKER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
For ret_status:
PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_OK = 0
PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_INVALID_MODE = 1
PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_NO_CHANGE = 2
PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
PIEZO_SPEAKER_V2_BOOTLOADER_STATUS_CRC_MISMATCH = 5
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Returns the current bootloader mode, see piezo_speaker_v2_set_bootloader_mode().
The following constants are available for this function:
For ret_mode:
PIEZO_SPEAKER_V2_BOOTLOADER_MODE_BOOTLOADER = 0
PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE = 1
PIEZO_SPEAKER_V2_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
PIEZO_SPEAKER_V2_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
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Sets the firmware pointer for piezo_speaker_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.
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Writes 64 Bytes of firmware at the position as written by
piezo_speaker_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.
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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.
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| Output Parameters: |
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Returns the current UID as an integer. Encode as Base58 to get the usual string version.
This constant is used to identify a Piezo Speaker Bricklet 2.0.
The piezo_speaker_v2_get_identity() function and the IPCON_CALLBACK_ENUMERATE
callback of the IP Connection have a device_identifier parameter to specify
the Brick's or Bricklet's type.
This constant represents the human readable name of a Piezo Speaker Bricklet 2.0.