mbed os with nrf51 internal bandgap enabled to read battery level
Dependents: BLE_file_test BLE_Blink ExternalEncoder
Diff: targets/TARGET_Freescale/TARGET_KLXX/analogout_api.c
- Revision:
- 0:f269e3021894
diff -r 000000000000 -r f269e3021894 targets/TARGET_Freescale/TARGET_KLXX/analogout_api.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/TARGET_Freescale/TARGET_KLXX/analogout_api.c Sun Oct 23 15:10:02 2016 +0000 @@ -0,0 +1,80 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2013 ARM Limited + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#include "mbed_assert.h" +#include "analogout_api.h" + +#include "cmsis.h" +#include "pinmap.h" +#include "PeripheralPins.h" + +#define RANGE_12BIT 0xFFF + +void analogout_init(dac_t *obj, PinName pin) { + obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC); + MBED_ASSERT(obj->dac != (DACName)NC); + + SIM->SCGC6 |= SIM_SCGC6_DAC0_MASK; + + uint32_t port = (uint32_t)pin >> PORT_SHIFT; + SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port); + + DAC0->DAT[obj->dac].DATH = 0; + DAC0->DAT[obj->dac].DATL = 0; + + DAC0->C1 = DAC_C1_DACBFMD_MASK; // One-Time Scan Mode + + DAC0->C0 = DAC_C0_DACEN_MASK // Enable + | DAC_C0_DACSWTRG_MASK; // Software Trigger + + pinmap_pinout(pin, PinMap_DAC); + + analogout_write_u16(obj, 0); +} + +void analogout_free(dac_t *obj) {} + +static inline void dac_write(dac_t *obj, int value) { + DAC0->DAT[obj->dac].DATL = (uint8_t)( value & 0xFF); + DAC0->DAT[obj->dac].DATH = (uint8_t)((value >> 8) & 0xFF); +} + +static inline int dac_read(dac_t *obj) { + return ((DAC0->DAT[obj->dac].DATH << 8) | DAC0->DAT[obj->dac].DATL); +} + +void analogout_write(dac_t *obj, float value) { + if (value < 0.0) { + dac_write(obj, 0); + } else if (value > 1.0) { + dac_write(obj, RANGE_12BIT); + } else { + dac_write(obj, value * (float)RANGE_12BIT); + } +} + +void analogout_write_u16(dac_t *obj, uint16_t value) { + dac_write(obj, value >> 4); // 12-bit +} + +float analogout_read(dac_t *obj) { + uint32_t value = dac_read(obj); + return (float)value * (1.0f / (float)RANGE_12BIT); +} + +uint16_t analogout_read_u16(dac_t *obj) { + uint32_t value = dac_read(obj); // 12-bit + return (value << 4) | ((value >> 8) & 0x003F); +}