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1f055d28b8
1. Modify I2S DAC built-in mode settings 2. Add I2S pdm mode 3. Correct I2S signal index in full-duplex mode 4. Modify dac output function 5. Add dac pad init functions 6. Modify DAC documentation 7. Add i2s_set_dac_mode API
49 lines
1.3 KiB
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49 lines
1.3 KiB
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Digital To Analog Converter
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===========================
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Overview
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--------
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ESP32 has two 8-bit DAC (digital to analog converter) channels, connected to GPIO25 (Channel 1) and GPIO26 (Channel 2).
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The DAC driver allows these channels to be set to arbitrary voltages.
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The DAC channels can also be driven with DMA-style written sample data, via the :doc:`I2S driver <i2s>` when using the "built-in DAC mode".
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For other analog output options, see the :doc:`Sigma-delta Modulation module <sigmadelta>` and the :doc:`LED Control module <ledc>`. Both these modules produce high frequency PWM output, which can be hardware low-pass filtered in order to generate a lower frequency analog output.
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Application Example
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-------------------
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Setting DAC channel 1 (GPIO 25) voltage to approx 0.78 of VDD_A voltage (VDD * 200 / 255). For VDD_A 3.3V, this is 2.59V::
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#include <driver/dac.h>
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...
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dac_output_enable(DAC_CHANNEL_1);
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dac_output_voltage(DAC_CHANNEL_1, 200);
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API Reference
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-------------
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Header Files
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^^^^^^^^^^^^
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* `components/driver/include/driver/dac.h`
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Enumerations
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^^^^^^^^^^^^
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.. doxygenenum:: dac_channel_t
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Functions
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^^^^^^^^^
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.. doxygenfunction:: dac_output_voltage
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.. doxygenfunction:: dac_output_enable
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.. doxygenfunction:: dac_output_disable
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.. doxygenfunction:: dac_i2s_enable
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.. doxygenfunction:: dac_i2s_disable
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