mbed library sources
Dependents: frdm_kl05z_gpio_test
Fork of mbed-src by
targets/hal/TARGET_NXP/TARGET_LPC13XX/analogin_api.c
- Committer:
- mbed_official
- Date:
- 2014-07-08
- Revision:
- 250:a49055e7a707
- Parent:
- 227:7bd0639b8911
- Child:
- 251:de9a1e4ffd79
File content as of revision 250:a49055e7a707:
/* 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 "analogin_api.h" #include "cmsis.h" #include "pinmap.h" #include "mbed_error.h" #define ANALOGIN_MEDIAN_FILTER 1 #define ADC_10BIT_RANGE 0x3FF #define ADC_12BIT_RANGE 0xFFF static inline int div_round_up(int x, int y) { return (x + (y - 1)) / y; } static const PinMap PinMap_ADC[] = { {P0_11, ADC0_0, 0x02}, {P0_12, ADC0_1, 0x02}, {P0_13, ADC0_2, 0x02}, {P0_14, ADC0_3, 0x02}, {P0_15, ADC0_4, 0x02}, {P0_16, ADC0_5, 0x01}, {P0_22, ADC0_6, 0x01}, {P0_23, ADC0_7, 0x01}, {NC , NC , 0 } }; #define LPC_IOCON0_BASE (LPC_IOCON_BASE) #define LPC_IOCON1_BASE (LPC_IOCON_BASE + 0x60) #define ADC_RANGE ADC_10BIT_RANGE void analogin_init(analogin_t *obj, PinName pin) { obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC); MBED_ASSERT(obj->adc != (ADCName)NC); // Power up ADC LPC_SYSCON->PDRUNCFG &= ~ (1 << 4); LPC_SYSCON->SYSAHBCLKCTRL |= ((uint32_t)1 << 13); uint32_t pin_number = (uint32_t)pin; __IO uint32_t *reg = (pin_number < 32) ? (__IO uint32_t*)(LPC_IOCON0_BASE + 4 * pin_number) : (__IO uint32_t*)(LPC_IOCON1_BASE + 4 * (pin_number - 32)); // set pin to ADC mode *reg &= ~(1 << 7); // set ADMODE = 0 (analog mode) uint32_t PCLK = SystemCoreClock; uint32_t MAX_ADC_CLK = 4500000; uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1; LPC_ADC->CR = (0 << 0) // no channels selected | (clkdiv << 8) // max of 4.5MHz | (0 << 16) // BURST = 0, software controlled | ( 0 << 17 ); // CLKS = 0, not applicable pinmap_pinout(pin, PinMap_ADC); } static inline uint32_t adc_read(analogin_t *obj) { // Select the appropriate channel and start conversion LPC_ADC->CR &= ~0xFF; LPC_ADC->CR |= 1 << (int)obj->adc; LPC_ADC->CR |= 1 << 24; // Repeatedly get the sample data until DONE bit unsigned int data; do { data = LPC_ADC->GDR; } while ((data & ((unsigned int)1 << 31)) == 0); // Stop conversion LPC_ADC->CR &= ~(1 << 24); return (data >> 6) & ADC_RANGE; // 10 bit } static inline void order(uint32_t *a, uint32_t *b) { if (*a > *b) { uint32_t t = *a; *a = *b; *b = t; } } static inline uint32_t adc_read_u32(analogin_t *obj) { uint32_t value; #if ANALOGIN_MEDIAN_FILTER uint32_t v1 = adc_read(obj); uint32_t v2 = adc_read(obj); uint32_t v3 = adc_read(obj); order(&v1, &v2); order(&v2, &v3); order(&v1, &v2); value = v2; #else value = adc_read(obj); #endif return value; } uint16_t analogin_read_u16(analogin_t *obj) { uint32_t value = adc_read_u32(obj); return (value << 6) | ((value >> 4) & 0x003F); // 10 bit } float analogin_read(analogin_t *obj) { uint32_t value = adc_read_u32(obj); return (float)value * (1.0f / (float)ADC_RANGE); }