mbed os with nrf51 internal bandgap enabled to read battery level

Dependents:   BLE_file_test BLE_Blink ExternalEncoder

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

Who changed what in which revision?

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elessair 0:f269e3021894 1 /* mbed Microcontroller Library
elessair 0:f269e3021894 2 * Copyright (c) 2006-2013 ARM Limited
elessair 0:f269e3021894 3 *
elessair 0:f269e3021894 4 * Licensed under the Apache License, Version 2.0 (the "License");
elessair 0:f269e3021894 5 * you may not use this file except in compliance with the License.
elessair 0:f269e3021894 6 * You may obtain a copy of the License at
elessair 0:f269e3021894 7 *
elessair 0:f269e3021894 8 * http://www.apache.org/licenses/LICENSE-2.0
elessair 0:f269e3021894 9 *
elessair 0:f269e3021894 10 * Unless required by applicable law or agreed to in writing, software
elessair 0:f269e3021894 11 * distributed under the License is distributed on an "AS IS" BASIS,
elessair 0:f269e3021894 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
elessair 0:f269e3021894 13 * See the License for the specific language governing permissions and
elessair 0:f269e3021894 14 * limitations under the License.
elessair 0:f269e3021894 15 */
elessair 0:f269e3021894 16 #include "mbed_assert.h"
elessair 0:f269e3021894 17 #include "analogout_api.h"
elessair 0:f269e3021894 18
elessair 0:f269e3021894 19 #include "cmsis.h"
elessair 0:f269e3021894 20 #include "pinmap.h"
elessair 0:f269e3021894 21 #include "PeripheralPins.h"
elessair 0:f269e3021894 22
elessair 0:f269e3021894 23 #define RANGE_12BIT 0xFFF
elessair 0:f269e3021894 24
elessair 0:f269e3021894 25 void analogout_init(dac_t *obj, PinName pin) {
elessair 0:f269e3021894 26 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
elessair 0:f269e3021894 27 MBED_ASSERT(obj->dac != (DACName)NC);
elessair 0:f269e3021894 28
elessair 0:f269e3021894 29 SIM->SCGC6 |= SIM_SCGC6_DAC0_MASK;
elessair 0:f269e3021894 30
elessair 0:f269e3021894 31 uint32_t port = (uint32_t)pin >> PORT_SHIFT;
elessair 0:f269e3021894 32 SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
elessair 0:f269e3021894 33
elessair 0:f269e3021894 34 DAC0->DAT[obj->dac].DATH = 0;
elessair 0:f269e3021894 35 DAC0->DAT[obj->dac].DATL = 0;
elessair 0:f269e3021894 36
elessair 0:f269e3021894 37 DAC0->C1 = DAC_C1_DACBFMD_MASK; // One-Time Scan Mode
elessair 0:f269e3021894 38
elessair 0:f269e3021894 39 DAC0->C0 = DAC_C0_DACEN_MASK // Enable
elessair 0:f269e3021894 40 | DAC_C0_DACSWTRG_MASK; // Software Trigger
elessair 0:f269e3021894 41
elessair 0:f269e3021894 42 pinmap_pinout(pin, PinMap_DAC);
elessair 0:f269e3021894 43
elessair 0:f269e3021894 44 analogout_write_u16(obj, 0);
elessair 0:f269e3021894 45 }
elessair 0:f269e3021894 46
elessair 0:f269e3021894 47 void analogout_free(dac_t *obj) {}
elessair 0:f269e3021894 48
elessair 0:f269e3021894 49 static inline void dac_write(dac_t *obj, int value) {
elessair 0:f269e3021894 50 DAC0->DAT[obj->dac].DATL = (uint8_t)( value & 0xFF);
elessair 0:f269e3021894 51 DAC0->DAT[obj->dac].DATH = (uint8_t)((value >> 8) & 0xFF);
elessair 0:f269e3021894 52 }
elessair 0:f269e3021894 53
elessair 0:f269e3021894 54 static inline int dac_read(dac_t *obj) {
elessair 0:f269e3021894 55 return ((DAC0->DAT[obj->dac].DATH << 8) | DAC0->DAT[obj->dac].DATL);
elessair 0:f269e3021894 56 }
elessair 0:f269e3021894 57
elessair 0:f269e3021894 58 void analogout_write(dac_t *obj, float value) {
elessair 0:f269e3021894 59 if (value < 0.0) {
elessair 0:f269e3021894 60 dac_write(obj, 0);
elessair 0:f269e3021894 61 } else if (value > 1.0) {
elessair 0:f269e3021894 62 dac_write(obj, RANGE_12BIT);
elessair 0:f269e3021894 63 } else {
elessair 0:f269e3021894 64 dac_write(obj, value * (float)RANGE_12BIT);
elessair 0:f269e3021894 65 }
elessair 0:f269e3021894 66 }
elessair 0:f269e3021894 67
elessair 0:f269e3021894 68 void analogout_write_u16(dac_t *obj, uint16_t value) {
elessair 0:f269e3021894 69 dac_write(obj, value >> 4); // 12-bit
elessair 0:f269e3021894 70 }
elessair 0:f269e3021894 71
elessair 0:f269e3021894 72 float analogout_read(dac_t *obj) {
elessair 0:f269e3021894 73 uint32_t value = dac_read(obj);
elessair 0:f269e3021894 74 return (float)value * (1.0f / (float)RANGE_12BIT);
elessair 0:f269e3021894 75 }
elessair 0:f269e3021894 76
elessair 0:f269e3021894 77 uint16_t analogout_read_u16(dac_t *obj) {
elessair 0:f269e3021894 78 uint32_t value = dac_read(obj); // 12-bit
elessair 0:f269e3021894 79 return (value << 4) | ((value >> 8) & 0x003F);
elessair 0:f269e3021894 80 }