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docs: Update full-scale voltages for ESP32-S2 chip

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Krzysztof 2020-12-28 11:54:51 +08:00
parent c65a24063d
commit 6df6123ff6
1 changed files with 69 additions and 65 deletions
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134
components/driver/include/driver/adc_common.h
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@ -195,58 +195,48 @@ 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 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
* @brief Set the attenuation of a particular channel on ADC1, and configure its associated GPIO pin mux.
*
* The default ADC voltage is for attenuation 0 dB and listed in the table below.
* By setting higher attenuation it is possible to read higher voltages.
*
* Due to ADC characteristics, most accurate results are obtained within the "suggested range"
* shown in the following table.
*
* +----------+-------------+-----------------+
* | | attenuation | suggested range |
* | SoC | (dB) | (mV) |
* +==========+=============+=================+
* | | 0 | 100 ~ 950 |
* | +-------------+-----------------+
* | | 2.5 | 100 ~ 1250 |
* | ESP32 +-------------+-----------------+
* | | 6 | 150 ~ 1750 |
* | +-------------+-----------------+
* | | 11 | 150 ~ 2450 |
* +----------+-------------+-----------------+
* | | 0 | 0 ~ 750 |
* | +-------------+-----------------+
* | | 2.5 | 0 ~ 1050 |
* | ESP32-S2 +-------------+-----------------+
* | | 6 | 0 ~ 1300 |
* | +-------------+-----------------+
* | | 11 | 0 ~ 2500 |
* +----------+-------------+-----------------+
*
* 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. 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);
@ -343,26 +333,40 @@ esp_err_t adc2_pad_get_io_num(adc2_channel_t channel, gpio_num_t *gpio_num);
/**
* @brief Configure the ADC2 channel, including setting attenuation.
*
* 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.
* The default ADC voltage is for attenuation 0 dB and listed in the table below.
* By setting higher attenuation it is possible to read higher voltages.
*
* When the analog voltage supply (VDDA) is 3.3 V:
* Due to ADC characteristics, most accurate results are obtained within the "suggested range"
* shown in the following table.
*
* - 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
* - 6 dB attenuation (ADC_ATTEN_6db) gives full-scale voltage 2.2 V
* - 11 dB attenuation (ADC_ATTEN_11db) gives full-scale voltage 3.9 V (see note below)
* +----------+-------------+-----------------+
* | | attenuation | suggested range |
* | SoC | (dB) | (mV) |
* +==========+=============+=================+
* | | 0 | 100 ~ 950 |
* | +-------------+-----------------+
* | | 2.5 | 100 ~ 1250 |
* | ESP32 +-------------+-----------------+
* | | 6 | 150 ~ 1750 |
* | +-------------+-----------------+
* | | 11 | 150 ~ 2450 |
* +----------+-------------+-----------------+
* | | 0 | 0 ~ 750 |
* | +-------------+-----------------+
* | | 2.5 | 0 ~ 1050 |
* | ESP32-S2 +-------------+-----------------+
* | | 6 | 0 ~ 1300 |
* | +-------------+-----------------+
* | | 11 | 0 ~ 2500 |
* +----------+-------------+-----------------+
*
* For maximum accuracy, use the ADC calibration APIs and measure voltages within these recommended ranges.
*
* @note This function also configures the input GPIO pin mux to
* connect it to the ADC2 channel. It must be called before calling
* ``adc2_get_raw()`` for this channel.
*
* @note The full-scale voltage is the voltage corresponding to a maximum reading
* (depending on ADC2 configured bit width,
* 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 VDDA, not the full scale voltage.
* @note For any given channel, this function must be called before the first time ``adc2_get_raw()`` is called for that channel.
*
* @param channel ADC2 channel to configure
* @param atten Attenuation level