tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC15XX/analogout_api.c

   1 /* mbed Microcontroller Library
   2  * Copyright (c) 2006-2013 ARM Limited
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 #include "mbed_assert.h"
  17 #include "analogout_api.h"
  18 #include "cmsis.h"
  19 #include "pinmap.h"
  20
  21 void analogout_init(dac_t *obj, PinName pin) {
  22     MBED_ASSERT(pin == P0_12);
  23
  24     LPC_SYSCON->SYSAHBCLKCTRL0 |= (1 << 29);
  25     LPC_SYSCON->PDRUNCFG &= ~(1 << 12);
  26     LPC_IOCON->PIO0_12 = 0;
  27     LPC_SWM->PINENABLE0 &= ~(1 << 24);
  28     LPC_DAC->CTRL = 0;
  29
  30     analogout_write_u16(obj, 0);
  31 }
  32
  33 void analogout_free(dac_t *obj)
  34 {
  35     LPC_SYSCON->SYSAHBCLKCTRL0 &= ~(1 << 29);
  36     LPC_SWM->PINENABLE0 |= (1 << 24);
  37 }
  38
  39 static inline void dac_write(int value) {
  40     value &= 0xFFF; // 12-bit
  41
  42     // Set the DAC output
  43     LPC_DAC->VAL = (value << 4);
  44 }
  45
  46 static inline int dac_read() {
  47     return ((LPC_DAC->VAL >> 4) & 0xFFF);
  48 }
  49
  50 void analogout_write(dac_t *obj, float value) {
  51     if (value < 0.0f) {
  52         dac_write(0);
  53     } else if (value > 1.0f) {
  54         dac_write(0xFFF);
  55     } else {
  56         dac_write((uint32_t)(value * (float)0xFFF));
  57     }
  58 }
  59
  60 void analogout_write_u16(dac_t *obj, uint16_t value) {
  61     dac_write(value);
  62 }
  63
  64 float analogout_read(dac_t *obj) {
  65     uint32_t value = dac_read();
  66     return (float)value * (1.0f / (float)0xFFF);
  67 }
  68
  69 uint16_t analogout_read_u16(dac_t *obj) {
  70     return (uint16_t)dac_read();
  71 }