mirror of https://github.com/ARMmbed/mbed-os.git
87 lines
2.2 KiB
C
87 lines
2.2 KiB
C
/* mbed Microcontroller Library
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* Copyright (c) 2006-2013 ARM Limited
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
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*/
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#include "mbed_assert.h"
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#include "analogout_api.h"
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#include "cmsis.h"
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#include "pinmap.h"
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#include "mbed_error.h"
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#include "gpio_api.h"
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static const PinMap PinMap_DAC[] = {
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#ifdef TARGET_LPC4337
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{P4_3, DAC_0, 0},
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#else
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{P4_4, DAC_0, 0},
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#endif
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{NC, NC, 0}
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};
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void analogout_init(dac_t *obj, PinName pin) {
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obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
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MBED_ASSERT(obj->dac != (DACName)NC);
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// Reset pin function to GPIO
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gpio_set(pin);
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// Select DAC on analog function select register in SCU
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LPC_SCU->ENAIO[2] |= 1; // Sets pin as DAC
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// Set bias=0 for maximum DAC update rate (1 MHz)
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LPC_DAC->CR &= ~DAC_BIAS_EN;
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// Enable DAC and DMA
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LPC_DAC->CTRL |= DAC_DMA_ENA;
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analogout_write_u16(obj, 0);
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}
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void analogout_free(dac_t *obj) {}
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static inline void dac_write(int value) {
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// Set the DAC output
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LPC_DAC->CR = DAC_SET(value);
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}
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static inline int dac_read() {
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return (DAC_GET(LPC_DAC->CR));
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}
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void analogout_write(dac_t *obj, float value) {
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if (value < 0.0f) {
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dac_write(0);
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} else if (value > 1.0f) {
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dac_write(DAC_RANGE);
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} else {
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dac_write(value * (float)DAC_RANGE);
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}
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}
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void analogout_write_u16(dac_t *obj, uint16_t value) {
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dac_write(value >> 6); // 10-bit
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}
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float analogout_read(dac_t *obj) {
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uint32_t value = dac_read();
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return (float)value * (1.0f / (float)DAC_RANGE);
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}
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uint16_t analogout_read_u16(dac_t *obj) {
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uint32_t value = dac_read(); // 10-bit
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return (value << 6) | ((value >> 4) & 0x003F);
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}
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