133 lines
3.9 KiB
Markdown
133 lines
3.9 KiB
Markdown
# I2S Module
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| Since | Origin / Contributor | Maintainer | Source |
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| :----- | :-------------------- | :---------- | :------ |
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| 2017-04-29 | zelll | [Arnim Läuger](https://github.com/devsaurus) | [i2s.c](../../components/modules/i2s.c)|
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The I2S module provides access to the in-built two I2S controllers.
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!!! note "DAC mode configuration"
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DACs are only available for DAC built-in mode on I2S peripheral 0.
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!!! note "ADC mode configuration"
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Only ADC1 is available for ADC built-in mode.
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## i2s.mute()
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Mute the I2S channel. The hardware buffer is instantly filled with silence.
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#### Syntax
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`i2s.mute(i2s_num)
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#### Parameters
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- `i2s_num` I2S peripheral 0 or 1
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#### Returns
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`nil`
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An error is thrown in case of invalid parameters or if the i2s driver failed.
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## i2s.read()
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Read data from I2S receive buffer.
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#### Syntax
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`i2s.read(i2s_num, size[, wait_ms])`
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#### Parameters
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- `i2s_num` I2S peripheral 0 or 1
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- `size` Bytes to read
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- `wait_ms` Millisecond to wait if data is not ready. Optional, defaults to 0 (not to wait) when omitted.
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#### Returns
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Data read from data-in pin. If data is not ready in `wait_ms` millisecond, less than `size` bytes can be returned.
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An error is thrown in case of invalid parameters or if the i2s driver failed.
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## i2s.start()
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Configuration and start I2S bus.
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#### Syntax
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```lua
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i2s.start(i2s_num, cfg, cb)
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```
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#### Parameters
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- `i2s_num` I2S peripheral 0 or 1
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- `cfg` table containing configuration data:
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- `mode` I2S work mode. Optional, defaults to `i2s.MODE_MASTER + i2s.MODE_TX` when omitted.
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- `i2s.MODE_MASTER`
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- `i2s.MODE_SLAVE`
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- `i2s.MODE_TX`
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- `i2s.MODE_RX`
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- `i2s.MODE_DAC_BUILT_IN`
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- `i2s.MODE_ADC_BUILT_IN`
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- `i2s.MODE_PDM`
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- `rate` audio sample rate. Optional, defauls to 44100 when omitted.
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- `bits` bits per sample. Optional, defaults to 16 when omitted.
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- `channel` channel format of I2S stream. Optional, defaults to `i2s.CHANNEL_RIGHT_LEFT` when omitted.
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- `i2s.CHANNEL_RIGHT_LEFT`
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- `i2s.CHANNEL_ALL_LEFT`
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- `i2s.CHANNEL_ONLY_LEFT`
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- `i2s.CHANNEL_ALL_RIGHT`
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- `i2s.CHANNEL_ONLY_RIGHT`
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- `format` communication format. Optional, defaults to `i2s.FORMAT_I2S + i2s.FORMAT_I2S_MSB` when omitted.
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- `i2s.FORMAT_I2S`
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- `i2s.FORMAT_I2S_MSB`
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- `i2s.FORMAT_I2S_LSB`
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- `i2s.FORMAT_PCM`
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- `i2s.FORMAT_PCM_SHORT`
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- `i2s.FORMAT_PCM_LONG`
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- `buffer_count` number of dma buffers. Optional, defaults to 2 when omitted.
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- `buffer_len` size of one dma buffer. Optional, defaults to rate/100 when omitted.
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- `bck_pin` clock pin, optional
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- `ws_pin` WS pin, optional
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- `data_out_pin` data output pin, optional
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- `data_in_pin` data input pin, optional
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- `dac_mode` DAC mode configuration. Optional, defaults to `i2s.DAC_CHANNEL_DISABLE` when omitted.
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- `i2s.DAC_CHANNEL_DISABLE`
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- `i2s.DAC_CHANNEL_RIGHT`
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- `i2s.DAC_CHANNEL_LEFT`
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- `i2s.DAC_CHANNEL_BOTH`
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- `adc1_channel` ADC1 channel number 0..7. Optional, defaults to off when omitted.
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- `cb` function called when transmit data is requested or received data is available
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- the function is called with parameters `i2s_num` and `dir`
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- `dir` is "tx" for TX data request. Function shall call `i2s.write()`.
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- `dir` is "rx" for RX data available. Function shall call `i2s.read()`.
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#### Returns
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`nil`
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An error is thrown in case of invalid parameters or if the i2s driver failed.
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## i2s.stop()
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Stop I2S bus.
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#### Syntax
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`i2s.stop(i2s_num)`
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#### Parameters
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- `i2s_num` I2S peripheral 0 or 1
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#### Returns
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`nil`
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An error is thrown in case of invalid parameters or if the i2s driver failed.
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## i2s.write()
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Write to I2S transmit buffer.
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#### Syntax
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`i2s.write(i2s_num, data)`
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#### Parameters
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- `i2s_num` I2S peripheral 0 or 1
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- `data` string containing I2S stream data
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#### Returns
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`nil`
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An error is thrown in case of invalid parameters or if the channel failed.
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