80 lines
3.6 KiB
C
80 lines
3.6 KiB
C
/*
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* MIT License
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*
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* Copyright (c) 2020 Joey Castillo
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#pragma once
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////< @file watch_adc.h
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#include "watch.h"
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/** @addtogroup adc Analog Input
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* @brief This section covers functions related to the SAM L22's analog-to-digital converter,
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* as well as configuring and reading values from the five analog-capable pins on the
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* 9-pin connector.
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*/
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/// @{
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/** @brief Enables the ADC peripheral. You must call this before attempting to read a value
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* from an analog pin.
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*/
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void watch_enable_adc(void);
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/** @brief Configures the selected pin for analog input.
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* @param pin One of the analog pins, access using the HAL_GPIO_Ax_pin() macro.
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*/
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void watch_enable_analog_input(const uint16_t pin);
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/** @brief Reads an analog value from one of the pins.
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* @param pin One of the analog pins, access using the HAL_GPIO_Ax_pin() macro.
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* @return a 16-bit unsigned integer from 0-65535 representing the sampled value, unless you
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* have changed the number of samples. @see watch_set_num_analog_samples for details
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* on how that function changes the values returned from this one.
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**/
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uint16_t watch_get_analog_pin_level(const uint16_t pin);
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/** @brief Returns the voltage of the VCC supply in millivolts (i.e. 3000 mV == 3.0 V). If running on
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* a coin cell, this will be the battery voltage.
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* @details Unlike other ADC functions, this function does not return a raw value from the ADC, but
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* rather scales it to an actual number of millivolts. This is because the ADC doesn't let
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* us measure VCC per se; it instead lets us measure VCC / 4, and we choose to measure it
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* against the internal reference voltage of 1.024 V. In short, the ADC gives us a number
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* that's complicated to deal with, so we just turn it into a useful number for you :)
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* @note This function depends on INTREF being 1.024V. If you have changed it by poking at the supply
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* controller's VREF.SEL bits, this function will return inaccurate values.
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*/
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uint16_t watch_get_vcc_voltage(void);
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/** @brief Disables the analog circuitry on the selected pin.
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* @param pin One of pins A0-A4.
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*/
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void watch_disable_analog_input(const uint16_t pin);
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/** @brief Disables the ADC peripheral.
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* @note You will need to call watch_enable_adc to re-enable the ADC peripheral. When you do, it will
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* have the default settings of 16 samples and 1 measurement cycle; if you customized these
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* parameters, you will need to set them up again.
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**/
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void watch_disable_adc(void);
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/// @}
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