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Digital To Analog Converter (DAC)
=================================
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{IDF_TARGET_DAC_CH_1: default = "GPIO25", esp32 = "GPIO25", esp32s2 = "GPIO17"}
{IDF_TARGET_DAC_CH_2: default = "GPIO26", esp32 = "GPIO26", esp32s2 = "GPIO18"}
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Overview
--------
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{IDF_TARGET_NAME} has two 8-bit DAC (digital to analog converter) channels, connected to {IDF_TARGET_DAC_CH_1} (Channel 1) and {IDF_TARGET_DAC_CH_2} (Channel 2).
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The DAC driver allows these channels to be set to arbitrary voltages.
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.. only :: esp32
The DAC channels can also be driven with DMA-style written sample data by the digital controller, via the :doc: `I2S driver <i2s>` when using the "built-in DAC mode".
.. only :: esp32s2
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The DAC channels can also be driven with DMA-style written sample data by the digital controller, however the driver does not supported this yet.
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For other analog output options, see the :doc: `Sigma-delta Modulation module <sdm>` and the :doc: `LED Control module <ledc>` . Both these modules produce high frequency PDM/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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Setting DAC channel 1 ({IDF_TARGET_DAC_CH_1}) 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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.. code :: c
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#include <driver/dac.h>
...
dac_output_enable(DAC_CHANNEL_1);
dac_output_voltage(DAC_CHANNEL_1, 200);
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API Reference
-------------
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.. include-build-file :: inc/dac.inc
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.. include-build-file :: inc/dac_common.inc
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GPIO Lookup Macros
^^^^^^^^^^^^^^^^^^
Some useful macros can be used to specified the GPIO number of a DAC channel, or vice versa.
e.g.
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1. `` DAC_CHANNEL_1_GPIO_NUM `` is the GPIO number of channel 1 ({IDF_TARGET_DAC_CH_1});
2. `` DAC_{IDF_TARGET_DAC_CH_2}_CHANNEL `` is the channel number of GPIO 26 (channel 2).
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.. include-build-file :: inc/dac_channel.inc
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.. include-build-file :: inc/dac_types.inc
