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targets/hal/TARGET_NXP/TARGET_LPC176X/analogout_api.c@0:9b334a45a8ff, 2015-10-01 (annotated)

Committer:
bogdanm
Date:
Thu Oct 01 15:25:22 2015 +0300
Revision:
0:9b334a45a8ff
Child:
144:ef7eb2e8f9f7
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 #include "mbed_assert.h"
bogdanm 0:9b334a45a8ff 17 #include "analogout_api.h"
bogdanm 0:9b334a45a8ff 18
bogdanm 0:9b334a45a8ff 19 #include "cmsis.h"
bogdanm 0:9b334a45a8ff 20 #include "pinmap.h"
bogdanm 0:9b334a45a8ff 21
bogdanm 0:9b334a45a8ff 22 static const PinMap PinMap_DAC[] = {
bogdanm 0:9b334a45a8ff 23 {P0_26, DAC_0, 2},
bogdanm 0:9b334a45a8ff 24 {NC , NC , 0}
bogdanm 0:9b334a45a8ff 25 };
bogdanm 0:9b334a45a8ff 26
bogdanm 0:9b334a45a8ff 27 void analogout_init(dac_t *obj, PinName pin) {
bogdanm 0:9b334a45a8ff 28 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
bogdanm 0:9b334a45a8ff 29 MBED_ASSERT(obj->dac != (DACName)NC);
bogdanm 0:9b334a45a8ff 30
bogdanm 0:9b334a45a8ff 31 // power is on by default, set DAC clk divider is /4
bogdanm 0:9b334a45a8ff 32 LPC_SC->PCLKSEL0 &= ~(0x3 << 22);
bogdanm 0:9b334a45a8ff 33
bogdanm 0:9b334a45a8ff 34 // map out (must be done before accessing registers)
bogdanm 0:9b334a45a8ff 35 pinmap_pinout(pin, PinMap_DAC);
bogdanm 0:9b334a45a8ff 36
bogdanm 0:9b334a45a8ff 37 analogout_write_u16(obj, 0);
bogdanm 0:9b334a45a8ff 38 }
bogdanm 0:9b334a45a8ff 39
bogdanm 0:9b334a45a8ff 40 void analogout_free(dac_t *obj) {}
bogdanm 0:9b334a45a8ff 41
bogdanm 0:9b334a45a8ff 42 static inline void dac_write(int value) {
bogdanm 0:9b334a45a8ff 43 value &= 0x3FF; // 10-bit
bogdanm 0:9b334a45a8ff 44
bogdanm 0:9b334a45a8ff 45 // Set the DAC output
bogdanm 0:9b334a45a8ff 46 LPC_DAC->DACR = (0 << 16) // bias = 0
bogdanm 0:9b334a45a8ff 47 | (value << 6);
bogdanm 0:9b334a45a8ff 48 }
bogdanm 0:9b334a45a8ff 49
bogdanm 0:9b334a45a8ff 50 static inline int dac_read() {
bogdanm 0:9b334a45a8ff 51 return (LPC_DAC->DACR >> 6) & 0x3FF;
bogdanm 0:9b334a45a8ff 52 }
bogdanm 0:9b334a45a8ff 53
bogdanm 0:9b334a45a8ff 54 void analogout_write(dac_t *obj, float value) {
bogdanm 0:9b334a45a8ff 55 if (value < 0.0f) {
bogdanm 0:9b334a45a8ff 56 dac_write(0);
bogdanm 0:9b334a45a8ff 57 } else if (value > 1.0f) {
bogdanm 0:9b334a45a8ff 58 dac_write(0x3FF);
bogdanm 0:9b334a45a8ff 59 } else {
bogdanm 0:9b334a45a8ff 60 dac_write(value * (float)0x3FF);
bogdanm 0:9b334a45a8ff 61 }
bogdanm 0:9b334a45a8ff 62 }
bogdanm 0:9b334a45a8ff 63
bogdanm 0:9b334a45a8ff 64 void analogout_write_u16(dac_t *obj, uint16_t value) {
bogdanm 0:9b334a45a8ff 65 dac_write(value >> 6); // 10-bit
bogdanm 0:9b334a45a8ff 66 }
bogdanm 0:9b334a45a8ff 67
bogdanm 0:9b334a45a8ff 68 float analogout_read(dac_t *obj) {
bogdanm 0:9b334a45a8ff 69 uint32_t value = dac_read();
bogdanm 0:9b334a45a8ff 70 return (float)value * (1.0f / (float)0x3FF);
bogdanm 0:9b334a45a8ff 71 }
bogdanm 0:9b334a45a8ff 72
bogdanm 0:9b334a45a8ff 73 uint16_t analogout_read_u16(dac_t *obj) {
bogdanm 0:9b334a45a8ff 74 uint32_t value = dac_read(); // 10-bit
bogdanm 0:9b334a45a8ff 75 return (value << 6) | ((value >> 4) & 0x003F);
bogdanm 0:9b334a45a8ff 76 }