mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

targets/TARGET_NXP/TARGET_LPC408X/analogout_api.c@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
Parent:
149:156823d33999 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2006-2013 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 */
<> 144:ef7eb2e8f9f7 16 #include "mbed_assert.h"
<> 144:ef7eb2e8f9f7 17 #include "analogout_api.h"
<> 144:ef7eb2e8f9f7 18 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 19 #include "pinmap.h"
<> 144:ef7eb2e8f9f7 20
<> 144:ef7eb2e8f9f7 21 static const PinMap PinMap_DAC[] = {
<> 144:ef7eb2e8f9f7 22 {P0_26, DAC_0, 2},
<> 144:ef7eb2e8f9f7 23 {NC , NC , 0}
<> 144:ef7eb2e8f9f7 24 };
<> 144:ef7eb2e8f9f7 25
<> 144:ef7eb2e8f9f7 26 void analogout_init(dac_t *obj, PinName pin) {
<> 144:ef7eb2e8f9f7 27 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
<> 144:ef7eb2e8f9f7 28 MBED_ASSERT(obj->dac != (DACName)NC);
<> 144:ef7eb2e8f9f7 29
<> 144:ef7eb2e8f9f7 30 // DAC enable bit must be set
<> 144:ef7eb2e8f9f7 31 LPC_IOCON->P0_26 |= (1 << 16); // DACEN
<> 144:ef7eb2e8f9f7 32
<> 144:ef7eb2e8f9f7 33 // map out (must be done before accessing registers)
<> 144:ef7eb2e8f9f7 34 pinmap_pinout(pin, PinMap_DAC);
<> 144:ef7eb2e8f9f7 35
<> 144:ef7eb2e8f9f7 36 analogout_write_u16(obj, 0);
<> 144:ef7eb2e8f9f7 37 }
<> 144:ef7eb2e8f9f7 38
<> 144:ef7eb2e8f9f7 39 void analogout_free(dac_t *obj) {}
<> 144:ef7eb2e8f9f7 40
<> 144:ef7eb2e8f9f7 41 static inline void dac_write(int value) {
<> 144:ef7eb2e8f9f7 42 value &= 0x3FF; // 10-bit
<> 144:ef7eb2e8f9f7 43
<> 144:ef7eb2e8f9f7 44 // Set the DAC output
<> 144:ef7eb2e8f9f7 45 LPC_DAC->CR = (0 << 16) // bias = 0
<> 144:ef7eb2e8f9f7 46 | (value << 6);
<> 144:ef7eb2e8f9f7 47 }
<> 144:ef7eb2e8f9f7 48
<> 144:ef7eb2e8f9f7 49 static inline int dac_read() {
<> 144:ef7eb2e8f9f7 50 return (LPC_DAC->CR >> 6) & 0x3FF;
<> 144:ef7eb2e8f9f7 51 }
<> 144:ef7eb2e8f9f7 52
<> 144:ef7eb2e8f9f7 53 void analogout_write(dac_t *obj, float value) {
<> 144:ef7eb2e8f9f7 54 if (value < 0.0f) {
<> 144:ef7eb2e8f9f7 55 dac_write(0);
<> 144:ef7eb2e8f9f7 56 } else if (value > 1.0f) {
<> 144:ef7eb2e8f9f7 57 dac_write(0x3FF);
<> 144:ef7eb2e8f9f7 58 } else {
<> 144:ef7eb2e8f9f7 59 dac_write(value * (float)0x3FF);
<> 144:ef7eb2e8f9f7 60 }
<> 144:ef7eb2e8f9f7 61 }
<> 144:ef7eb2e8f9f7 62
<> 144:ef7eb2e8f9f7 63 void analogout_write_u16(dac_t *obj, uint16_t value) {
<> 144:ef7eb2e8f9f7 64 dac_write(value >> 6); // 10-bit
<> 144:ef7eb2e8f9f7 65 }
<> 144:ef7eb2e8f9f7 66
<> 144:ef7eb2e8f9f7 67 float analogout_read(dac_t *obj) {
<> 144:ef7eb2e8f9f7 68 uint32_t value = dac_read();
<> 144:ef7eb2e8f9f7 69 return (float)value * (1.0f / (float)0x3FF);
<> 144:ef7eb2e8f9f7 70 }
<> 144:ef7eb2e8f9f7 71
<> 144:ef7eb2e8f9f7 72 uint16_t analogout_read_u16(dac_t *obj) {
<> 144:ef7eb2e8f9f7 73 uint32_t value = dac_read(); // 10-bit
<> 144:ef7eb2e8f9f7 74 return (value << 6) | ((value >> 4) & 0x003F);
<> 144:ef7eb2e8f9f7 75 }