/****************************************************************************** * The MIT License * * Copyright (c) 2010 Bryan Newbold. * Copyright (c) 2011, 2012 LeafLabs, LLC. * * 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. *****************************************************************************/ /** * @file libmaple/dac.c * @brief Digital to analog converter support. */ #include <libmaple/dac.h> #include <libmaple/libmaple.h> #include <libmaple/gpio.h> #if STM32_HAVE_DAC dac_dev dac = { .regs = DAC_BASE, }; const dac_dev *DAC = &dac; #endif /** * @brief Initialize the digital to analog converter * @param dev DAC device * @param flags Flags: * DAC_CH1: Enable channel 1 * DAC_CH2: Enable channel 2 * @sideeffect May set PA4 or PA5 to INPUT_ANALOG */ void dac_init(const dac_dev *dev, uint32 flags) { /* First turn on the clock */ rcc_clk_enable(RCC_DAC); rcc_reset_dev(RCC_DAC); if (flags & DAC_CH1) { dac_enable_channel(dev, 1); } if (flags & DAC_CH2) { dac_enable_channel(dev, 2); } } /** * @brief Write a 12-bit value to the DAC to output * @param dev DAC device * @param channel channel to select (1 or 2) * @param val value to write */ void dac_write_channel(const dac_dev *dev, uint8 channel, uint16 val) { switch(channel) { case 1: dev->regs->DHR12R1 = DAC_DHR12R1_DACC1DHR & val; break; case 2: dev->regs->DHR12R2 = DAC_DHR12R2_DACC2DHR & val; break; } } /** * @brief Enable a DAC channel * @param dev DAC device * @param channel channel to enable, either 1 or 2 * @sideeffect May change pin mode of PA4 or PA5 */ void dac_enable_channel(const dac_dev *dev, uint8 channel) { /* * Setup ANALOG mode on PA4 and PA5. This mapping is consistent * across all supported STM32s with a DAC. */ switch (channel) { case 1: gpio_set_mode(GPIOA, 4, GPIO_MODE_ANALOG); dev->regs->CR |= DAC_CR_EN1; break; case 2: gpio_set_mode(GPIOA, 5, GPIO_MODE_ANALOG); dev->regs->CR |= DAC_CR_EN2; break; } } /** * @brief Disable a DAC channel * @param dev DAC device * @param channel channel to disable, either 1 or 2 */ void dac_disable_channel(const dac_dev *dev, uint8 channel) { switch (channel) { case 1: dev->regs->CR &= ~DAC_CR_EN1; break; case 2: dev->regs->CR &= ~DAC_CR_EN2; break; } }