This is the description of the Modbus protocol for the Piezo Speaker Bricklet. General information and technical specifications for the Piezo Speaker Bricklet are summarized in its hardware description.
A general description of the Modbus protocol structure can be found here.
Function ID: | 1 |
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Request: |
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Response: | no response |
Beeps with the given frequency for the duration in ms. For example: If you set a duration of 1000, with a frequency value of 2000 the piezo buzzer will beep for one second with a frequency of approximately 2 kHz.
Changed in version 2.0.2 (Plugin): A duration of 0 stops the current beep if any, the frequency parameter is ignored. A duration of 4294967295 results in an infinite beep.
The frequency parameter can be set between 585 and 7100.
The Piezo Speaker Bricklet can only approximate the frequency, it will play the best possible match by applying the calibration (see calibrate).
Function ID: | 2 |
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Request: |
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Response: | no response |
Sets morse code that will be played by the piezo buzzer. The morse code is given as a string consisting of "." (dot), "-" (minus) and " " (space) for dits, dahs and pauses. Every other character is ignored. The second parameter is the frequency (see beep).
For example: If you set the string "...---...", the piezo buzzer will beep nine times with the durations "short short short long long long short short short".
The maximum string size is 60.
Function ID: | 3 |
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Request: | empty payload |
Response: |
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The Piezo Speaker Bricklet can play 512 different tones. This function plays each tone and measures the exact frequency back. The result is a mapping between setting value and frequency. This mapping is stored in the EEPROM and loaded on startup.
The Bricklet should come calibrated, you only need to call this function (once) every time you reflash the Bricklet plugin.
Returns true after the calibration finishes.
Function ID: | 255 |
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Request: | empty payload |
Response: |
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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' or 'd'.
The device identifier numbers can be found here.
Function ID: | 4 |
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Response: | empty payload |
This callback is triggered if a beep set by beep is finished
Function ID: | 5 |
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Response: | empty payload |
This callback is triggered if the playback of the morse code set by morse_code is finished.