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doc/adc: modifications in the adc documentation and adc headers

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This commit is contained in:
Wu Bo Wen
2020-07-15 11:19:29 +08:00
committed by bot
parent 5c5c7c4449
commit 658b56a690
4 changed files with 187 additions and 185 deletions
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109
components/driver/include/driver/adc_common.h
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@@ -76,7 +76,7 @@ typedef enum {
/**
* @brief ADC digital controller encode option.
*
* @deprecated The ESP32S2 don't use I2S DMA. Call ``adc_digi_output_format_t`` instead.
* @deprecated The ESP32-S2 doesn't use I2S DMA. Call ``adc_digi_output_format_t`` instead.
*/
typedef enum {
ADC_ENCODE_12BIT, /*!< ADC to DMA data format, , [15:12]-channel [11:0]-12 bits ADC data */
@@ -126,45 +126,58 @@ esp_err_t adc_gpio_init(adc_unit_t adc_unit, adc_channel_t channel);
esp_err_t adc1_pad_get_io_num(adc1_channel_t channel, gpio_num_t *gpio_num);
/**
* @brief Set the attenuation of a particular channel on ADC1, and configure its associated GPIO pin mux.
*
* The default ADC full-scale voltage is 1.1 V. To read higher voltages (up to the pin maximum voltage,
* usually 3.3 V) requires setting >0 dB signal attenuation for that ADC channel.
*
* When VDD_A is 3.3 V:
*
* - 0 dB attenuation (ADC_ATTEN_DB_0) gives full-scale voltage 1.1 V
* - 2.5 dB attenuation (ADC_ATTEN_DB_2_5) gives full-scale voltage 1.5 V
* - 6 dB attenuation (ADC_ATTEN_DB_6) gives full-scale voltage 2.2 V
* - 11 dB attenuation (ADC_ATTEN_DB_11) gives full-scale voltage 3.9 V (see note below)
*
* @note The full-scale voltage is the voltage corresponding to a maximum reading (depending on ADC1 configured bit width,
* this value in ESP32 is: 4095 for 12-bits, 2047 for 11-bits, 1023 for 10-bits, 511 for 9 bits.
* this value in ESP32S2 is: 8191 for 13-bits.)
*
* @note At 11 dB attenuation the maximum voltage is limited by VDD_A, not the full scale voltage.
*
* @note For ESP32:
* Due to ADC characteristics, most accurate results are obtained within the following approximate voltage ranges:
*
* - 0 dB attenuation (ADC_ATTEN_DB_0) between 100 and 950 mV
* - 2.5 dB attenuation (ADC_ATTEN_DB_2_5) between 100 and 1250 mV
* - 6 dB attenuation (ADC_ATTEN_DB_6) between 150 to 1750 mV
* - 11 dB attenuation (ADC_ATTEN_DB_11) between 150 to 2450 mV
*
* For maximum accuracy, use the ADC calibration APIs and measure voltages within these recommended ranges.
*
* @note For any given channel, this function must be called before the first time ``adc1_get_raw()`` is called for that channel.
*
* @note This function can be called multiple times to configure multiple
* ADC channels simultaneously. ``adc1_get_raw()`` can then be called for any configured channel.
*
* @param channel ADC1 channel to configure
* @param atten Attenuation level
*
* @return
* - ESP_OK success
* - ESP_ERR_INVALID_ARG Parameter error
* @brief Set the attenuation of a particular channel on ADC1, and configure its associated GPIO pin mux.
*
* The default ADC full-scale voltage is 1.1 V. To read higher voltages (up to the pin maximum voltage,
* usually 3.3 V) requires setting >0 dB signal attenuation for that ADC channel.
*
* When the analog voltage supply (VDDA) is 3.3 V:
*
* - 0 dB attenuation (ADC_ATTEN_DB_0) gives full-scale voltage 1.1 V
* - 2.5 dB attenuation (ADC_ATTEN_DB_2_5) gives full-scale voltage 1.5 V
* - 6 dB attenuation (ADC_ATTEN_DB_6) gives full-scale voltage 2.2 V
* - 11 dB attenuation (ADC_ATTEN_DB_11) gives full-scale voltage 3.9 V (see note below)
*
* Due to ADC characteristics, most accurate results are obtained within the following approximate voltage ranges:
*
* +----------+------------+--------------------------+
* | SoC | attenuation| suggested range (mV) |
* +==========+============+==========================+
* | | 0 | 100 ~ 950 |
* | +------------+--------------------------+
* | | 2.5 | 100 ~ 1250 |
* | ESP32 +------------+--------------------------+
* | | 6 | 150 ~ 1750 |
* | +------------+--------------------------+
* | | 11 | 150 ~ 2450 |
* +----------+------------+--------------------------+
* | | 0 | 100 ~ 800 |
* | +------------+--------------------------+
* | | 2.5 | 100 ~ 1100 |
* | ESP32-S2 +------------+--------------------------+
* | | 6 | 150 ~ 1350 |
* | +------------+--------------------------+
* | | 11 | 150 ~ 2600 |
* +----------+------------+--------------------------+
*
* For maximum accuracy, use the ADC calibration APIs and measure voltages within these recommended ranges.
* @note The full-scale voltage is the voltage corresponding to a maximum reading (depending on ADC1 configured bit width,
* this value in ESP32 is 4095 for 12-bits, 2047 for 11-bits, 1023 for 10-bits, 511 for 9 bits.
* this value in ESP32-S2 is 8191 for 13-bits.)
*
* @note At 11 dB attenuation the maximum voltage is limited by VDDA, not the full scale voltage.
*
* @note For any given channel, this function must be called before the first time ``adc1_get_raw()`` is called for that channel.
*
* @note This function can be called multiple times to configure multiple
* ADC channels simultaneously. You may call ``adc1_get_raw()`` only after configuring a channel.
*
* @param channel ADC1 channel to configure
* @param atten Attenuation level
*
* @return
* - ESP_OK success
* - ESP_ERR_INVALID_ARG Parameter error
*/
esp_err_t adc1_config_channel_atten(adc1_channel_t channel, adc_atten_t atten);
@@ -223,10 +236,10 @@ esp_err_t adc_set_clk_div(uint8_t clk_div);
/**
* @brief Configure ADC capture width.
*
* @note For ESP32S2, only support ``ADC_WIDTH_BIT_13``.
* @note ESP32-S2 only supports ``ADC_WIDTH_BIT_13``.
*
* @param adc_unit ADC unit index
* @param width_bit Bit capture width for ADC unit. For ESP32S2, only support ``ADC_WIDTH_BIT_13``.
* @param width_bit Bit capture width for ADC unit. ESP32-S2 only supports ``ADC_WIDTH_BIT_13``.
*
* @return
* - ESP_OK success
@@ -264,7 +277,7 @@ esp_err_t adc2_pad_get_io_num(adc2_channel_t channel, gpio_num_t *gpio_num);
* The default ADC full-scale voltage is 1.1 V. To read higher voltages (up to the pin maximum voltage,
* usually 3.3 V) requires setting >0 dB signal attenuation for that ADC channel.
*
* When VDD_A is 3.3 V:
* When the analog voltage supply (VDDA) is 3.3 V:
*
* - 0 dB attenuation (ADC_ATTEN_0db) gives full-scale voltage 1.1 V
* - 2.5 dB attenuation (ADC_ATTEN_2_5db) gives full-scale voltage 1.5 V
@@ -277,10 +290,10 @@ esp_err_t adc2_pad_get_io_num(adc2_channel_t channel, gpio_num_t *gpio_num);
*
* @note The full-scale voltage is the voltage corresponding to a maximum reading
* (depending on ADC2 configured bit width,
* this value of ESP32 is: 4095 for 12-bits, 2047 for 11-bits, 1023 for 10-bits, 511 for 9 bits.
* this value of ESP32S2 is: 8191 for 13-bits.)
* this value for ESP32 is: 4095 for 12-bits, 2047 for 11-bits, 1023 for 10-bits, 511 for 9 bits.
* this value for ESP32-S2 is: 8191 for 13-bits.)
*
* @note At 11 dB attenuation the maximum voltage is limited by VDD_A, not the full scale voltage.
* @note At 11 dB attenuation the maximum voltage is limited by VDDA, not the full scale voltage.
*
* @param channel ADC2 channel to configure
* @param atten Attenuation level
@@ -305,12 +318,12 @@ esp_err_t adc2_config_channel_atten(adc2_channel_t channel, adc_atten_t atten);
* must be called before the first time this function is called. If Wi-Fi is started via ``esp_wifi_start()``, this
* function will always fail with ``ESP_ERR_TIMEOUT``.
*
* @note ESP32S2:
* @note ESP32-S2:
* ADC2 support hardware arbiter. The arbiter is to improve the use efficiency of ADC2. After the control right is robbed by the high priority,
* the low priority controller will read the invalid ADC2 data. Default priority: Wi-Fi > RTC > Digital;
*
* @param channel ADC2 channel to read
* @param width_bit Bit capture width for ADC2. For ESP32S2, only support ``ADC_WIDTH_BIT_13``.
* @param width_bit Bit capture width for ADC2. ESP32-S2 only supports ``ADC_WIDTH_BIT_13``.
* @param raw_out the variable to hold the output data.
*
* @return