EL4121 Embedded System / mbed-os

mbed-os

Dependents:   cobaLCDJoyMotor_Thread odometry_omni_3roda_v3 odometry_omni_3roda_v1 odometry_omni_3roda_v2 ... more

targets/TARGET_NXP/TARGET_LPC43XX/analogout_api.c@0:b74591d5ab33, 2017-12-11 (annotated)

Committer:
be_bryan
Date:
Mon Dec 11 17:54:04 2017 +0000
Revision:
0:b74591d5ab33
motor ++

Who changed what in which revision?

UserRevisionLine numberNew contents of line
be_bryan 0:b74591d5ab33 1 /* mbed Microcontroller Library
be_bryan 0:b74591d5ab33 2 * Copyright (c) 2006-2013 ARM Limited
be_bryan 0:b74591d5ab33 3 *
be_bryan 0:b74591d5ab33 4 * Licensed under the Apache License, Version 2.0 (the "License");
be_bryan 0:b74591d5ab33 5 * you may not use this file except in compliance with the License.
be_bryan 0:b74591d5ab33 6 * You may obtain a copy of the License at
be_bryan 0:b74591d5ab33 7 *
be_bryan 0:b74591d5ab33 8 * http://www.apache.org/licenses/LICENSE-2.0
be_bryan 0:b74591d5ab33 9 *
be_bryan 0:b74591d5ab33 10 * Unless required by applicable law or agreed to in writing, software
be_bryan 0:b74591d5ab33 11 * distributed under the License is distributed on an "AS IS" BASIS,
be_bryan 0:b74591d5ab33 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
be_bryan 0:b74591d5ab33 13 * See the License for the specific language governing permissions and
be_bryan 0:b74591d5ab33 14 * limitations under the License.
be_bryan 0:b74591d5ab33 15 *
be_bryan 0:b74591d5ab33 16 * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
be_bryan 0:b74591d5ab33 17 */
be_bryan 0:b74591d5ab33 18 #include "mbed_assert.h"
be_bryan 0:b74591d5ab33 19 #include "analogout_api.h"
be_bryan 0:b74591d5ab33 20
be_bryan 0:b74591d5ab33 21 #include "cmsis.h"
be_bryan 0:b74591d5ab33 22 #include "pinmap.h"
be_bryan 0:b74591d5ab33 23 #include "mbed_error.h"
be_bryan 0:b74591d5ab33 24 #include "gpio_api.h"
be_bryan 0:b74591d5ab33 25
be_bryan 0:b74591d5ab33 26 static const PinMap PinMap_DAC[] = {
be_bryan 0:b74591d5ab33 27 #ifdef TARGET_LPC4337
be_bryan 0:b74591d5ab33 28 {P4_3, DAC_0, 0},
be_bryan 0:b74591d5ab33 29 #else
be_bryan 0:b74591d5ab33 30 {P4_4, DAC_0, 0},
be_bryan 0:b74591d5ab33 31 #endif
be_bryan 0:b74591d5ab33 32 {NC, NC, 0}
be_bryan 0:b74591d5ab33 33 };
be_bryan 0:b74591d5ab33 34
be_bryan 0:b74591d5ab33 35 void analogout_init(dac_t *obj, PinName pin) {
be_bryan 0:b74591d5ab33 36 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
be_bryan 0:b74591d5ab33 37 MBED_ASSERT(obj->dac != (DACName)NC);
be_bryan 0:b74591d5ab33 38
be_bryan 0:b74591d5ab33 39 // Reset pin function to GPIO
be_bryan 0:b74591d5ab33 40 gpio_set(pin);
be_bryan 0:b74591d5ab33 41 // Select DAC on analog function select register in SCU
be_bryan 0:b74591d5ab33 42 LPC_SCU->ENAIO[2] |= 1; // Sets pin as DAC
be_bryan 0:b74591d5ab33 43
be_bryan 0:b74591d5ab33 44 // Set bias=0 for maximum DAC update rate (1 MHz)
be_bryan 0:b74591d5ab33 45 LPC_DAC->CR &= ~DAC_BIAS_EN;
be_bryan 0:b74591d5ab33 46 // Enable DAC and DMA
be_bryan 0:b74591d5ab33 47 LPC_DAC->CTRL |= DAC_DMA_ENA;
be_bryan 0:b74591d5ab33 48
be_bryan 0:b74591d5ab33 49 analogout_write_u16(obj, 0);
be_bryan 0:b74591d5ab33 50 }
be_bryan 0:b74591d5ab33 51
be_bryan 0:b74591d5ab33 52 void analogout_free(dac_t *obj) {}
be_bryan 0:b74591d5ab33 53
be_bryan 0:b74591d5ab33 54 static inline void dac_write(int value) {
be_bryan 0:b74591d5ab33 55
be_bryan 0:b74591d5ab33 56 // Set the DAC output
be_bryan 0:b74591d5ab33 57 LPC_DAC->CR = DAC_SET(value);
be_bryan 0:b74591d5ab33 58 }
be_bryan 0:b74591d5ab33 59
be_bryan 0:b74591d5ab33 60 static inline int dac_read() {
be_bryan 0:b74591d5ab33 61 return (DAC_GET(LPC_DAC->CR));
be_bryan 0:b74591d5ab33 62 }
be_bryan 0:b74591d5ab33 63
be_bryan 0:b74591d5ab33 64 void analogout_write(dac_t *obj, float value) {
be_bryan 0:b74591d5ab33 65 if (value < 0.0f) {
be_bryan 0:b74591d5ab33 66 dac_write(0);
be_bryan 0:b74591d5ab33 67 } else if (value > 1.0f) {
be_bryan 0:b74591d5ab33 68 dac_write(DAC_RANGE);
be_bryan 0:b74591d5ab33 69 } else {
be_bryan 0:b74591d5ab33 70 dac_write(value * (float)DAC_RANGE);
be_bryan 0:b74591d5ab33 71 }
be_bryan 0:b74591d5ab33 72 }
be_bryan 0:b74591d5ab33 73
be_bryan 0:b74591d5ab33 74 void analogout_write_u16(dac_t *obj, uint16_t value) {
be_bryan 0:b74591d5ab33 75 dac_write(value >> 6); // 10-bit
be_bryan 0:b74591d5ab33 76 }
be_bryan 0:b74591d5ab33 77
be_bryan 0:b74591d5ab33 78 float analogout_read(dac_t *obj) {
be_bryan 0:b74591d5ab33 79 uint32_t value = dac_read();
be_bryan 0:b74591d5ab33 80 return (float)value * (1.0f / (float)DAC_RANGE);
be_bryan 0:b74591d5ab33 81 }
be_bryan 0:b74591d5ab33 82
be_bryan 0:b74591d5ab33 83 uint16_t analogout_read_u16(dac_t *obj) {
be_bryan 0:b74591d5ab33 84 uint32_t value = dac_read(); // 10-bit
be_bryan 0:b74591d5ab33 85 return (value << 6) | ((value >> 4) & 0x003F);
be_bryan 0:b74591d5ab33 86 }