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