b luo / mbed-dev

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Fork of mbed-dev by mbed official

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 }