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targets/hal/TARGET_NXP/TARGET_LPC43XX/analogout_api.c@0:9b334a45a8ff, 2015-10-01 (annotated)

Committer:
bogdanm
Date:
Thu Oct 01 15:25:22 2015 +0300
Revision:
0:9b334a45a8ff
Initial commit on mbed-dev



Replaces mbed-src (now inactive)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 0:9b334a45a8ff 1 /* mbed Microcontroller Library
bogdanm 0:9b334a45a8ff 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 0:9b334a45a8ff 3 *
bogdanm 0:9b334a45a8ff 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 0:9b334a45a8ff 5 * you may not use this file except in compliance with the License.
bogdanm 0:9b334a45a8ff 6 * You may obtain a copy of the License at
bogdanm 0:9b334a45a8ff 7 *
bogdanm 0:9b334a45a8ff 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 0:9b334a45a8ff 9 *
bogdanm 0:9b334a45a8ff 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 0:9b334a45a8ff 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 0:9b334a45a8ff 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 0:9b334a45a8ff 13 * See the License for the specific language governing permissions and
bogdanm 0:9b334a45a8ff 14 * limitations under the License.
bogdanm 0:9b334a45a8ff 15 *
bogdanm 0:9b334a45a8ff 16 * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
bogdanm 0:9b334a45a8ff 17 */
bogdanm 0:9b334a45a8ff 18 #include "mbed_assert.h"
bogdanm 0:9b334a45a8ff 19 #include "analogout_api.h"
bogdanm 0:9b334a45a8ff 20
bogdanm 0:9b334a45a8ff 21 #include "cmsis.h"
bogdanm 0:9b334a45a8ff 22 #include "pinmap.h"
bogdanm 0:9b334a45a8ff 23 #include "mbed_error.h"
bogdanm 0:9b334a45a8ff 24 #include "gpio_api.h"
bogdanm 0:9b334a45a8ff 25
bogdanm 0:9b334a45a8ff 26 static const PinMap PinMap_DAC[] = {
bogdanm 0:9b334a45a8ff 27 #ifdef TARGET_LPC4337
bogdanm 0:9b334a45a8ff 28 {P4_3, DAC_0, 0},
bogdanm 0:9b334a45a8ff 29 #else
bogdanm 0:9b334a45a8ff 30 {P4_4, DAC_0, 0},
bogdanm 0:9b334a45a8ff 31 #endif
bogdanm 0:9b334a45a8ff 32 {NC, NC, 0}
bogdanm 0:9b334a45a8ff 33 };
bogdanm 0:9b334a45a8ff 34
bogdanm 0:9b334a45a8ff 35 void analogout_init(dac_t *obj, PinName pin) {
bogdanm 0:9b334a45a8ff 36 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
bogdanm 0:9b334a45a8ff 37 MBED_ASSERT(obj->dac != (DACName)NC);
bogdanm 0:9b334a45a8ff 38
bogdanm 0:9b334a45a8ff 39 // Reset pin function to GPIO
bogdanm 0:9b334a45a8ff 40 gpio_set(pin);
bogdanm 0:9b334a45a8ff 41 // Select DAC on analog function select register in SCU
bogdanm 0:9b334a45a8ff 42 LPC_SCU->ENAIO[2] |= 1; // Sets pin as DAC
bogdanm 0:9b334a45a8ff 43
bogdanm 0:9b334a45a8ff 44 // Set bias=0 for maximum DAC update rate (1 MHz)
bogdanm 0:9b334a45a8ff 45 LPC_DAC->CR &= ~DAC_BIAS_EN;
bogdanm 0:9b334a45a8ff 46 // Enable DAC and DMA
bogdanm 0:9b334a45a8ff 47 LPC_DAC->CTRL |= DAC_DMA_ENA;
bogdanm 0:9b334a45a8ff 48
bogdanm 0:9b334a45a8ff 49 analogout_write_u16(obj, 0);
bogdanm 0:9b334a45a8ff 50 }
bogdanm 0:9b334a45a8ff 51
bogdanm 0:9b334a45a8ff 52 void analogout_free(dac_t *obj) {}
bogdanm 0:9b334a45a8ff 53
bogdanm 0:9b334a45a8ff 54 static inline void dac_write(int value) {
bogdanm 0:9b334a45a8ff 55
bogdanm 0:9b334a45a8ff 56 // Set the DAC output
bogdanm 0:9b334a45a8ff 57 LPC_DAC->CR = DAC_SET(value);
bogdanm 0:9b334a45a8ff 58 }
bogdanm 0:9b334a45a8ff 59
bogdanm 0:9b334a45a8ff 60 static inline int dac_read() {
bogdanm 0:9b334a45a8ff 61 return (DAC_GET(LPC_DAC->CR));
bogdanm 0:9b334a45a8ff 62 }
bogdanm 0:9b334a45a8ff 63
bogdanm 0:9b334a45a8ff 64 void analogout_write(dac_t *obj, float value) {
bogdanm 0:9b334a45a8ff 65 if (value < 0.0f) {
bogdanm 0:9b334a45a8ff 66 dac_write(0);
bogdanm 0:9b334a45a8ff 67 } else if (value > 1.0f) {
bogdanm 0:9b334a45a8ff 68 dac_write(DAC_RANGE);
bogdanm 0:9b334a45a8ff 69 } else {
bogdanm 0:9b334a45a8ff 70 dac_write(value * (float)DAC_RANGE);
bogdanm 0:9b334a45a8ff 71 }
bogdanm 0:9b334a45a8ff 72 }
bogdanm 0:9b334a45a8ff 73
bogdanm 0:9b334a45a8ff 74 void analogout_write_u16(dac_t *obj, uint16_t value) {
bogdanm 0:9b334a45a8ff 75 dac_write(value >> 6); // 10-bit
bogdanm 0:9b334a45a8ff 76 }
bogdanm 0:9b334a45a8ff 77
bogdanm 0:9b334a45a8ff 78 float analogout_read(dac_t *obj) {
bogdanm 0:9b334a45a8ff 79 uint32_t value = dac_read();
bogdanm 0:9b334a45a8ff 80 return (float)value * (1.0f / (float)DAC_RANGE);
bogdanm 0:9b334a45a8ff 81 }
bogdanm 0:9b334a45a8ff 82
bogdanm 0:9b334a45a8ff 83 uint16_t analogout_read_u16(dac_t *obj) {
bogdanm 0:9b334a45a8ff 84 uint32_t value = dac_read(); // 10-bit
bogdanm 0:9b334a45a8ff 85 return (value << 6) | ((value >> 4) & 0x003F);
bogdanm 0:9b334a45a8ff 86 }