Ernesto Palacios / FastAnalogIn

FastAnalogIn

Fork of FastAnalogIn by Erik -

FastAnalogIn_LPC408X.cpp@12:46fbc645de4d, 2016-03-21 (annotated)

Committer:
Sissors
Date:
Mon Mar 21 07:41:52 2016 +0000
Revision:
12:46fbc645de4d
Parent:
7:965a2b0e477f 
Fixed pinmapping of LPC1114

Who changed what in which revision?

UserRevisionLine numberNew contents of line
humlet 4:cd84739f7640 1 #ifdef TARGET_LPC408X
humlet 4:cd84739f7640 2
humlet 4:cd84739f7640 3 #include "FastAnalogIn.h"
humlet 4:cd84739f7640 4
humlet 4:cd84739f7640 5 static inline int div_round_up(int x, int y)
humlet 4:cd84739f7640 6 {
humlet 4:cd84739f7640 7 return (x + (y - 1)) / y;
humlet 4:cd84739f7640 8 }
humlet 4:cd84739f7640 9
humlet 4:cd84739f7640 10 static const PinMap PinMap_ADC[] = {
humlet 4:cd84739f7640 11 {P0_23, ADC0_0, 0x01},
humlet 4:cd84739f7640 12 {P0_24, ADC0_1, 0x01},
humlet 4:cd84739f7640 13 {P0_25, ADC0_2, 0x01},
humlet 4:cd84739f7640 14 {P0_26, ADC0_3, 0x01},
humlet 4:cd84739f7640 15 {P1_30, ADC0_4, 0x03},
humlet 4:cd84739f7640 16 {P1_31, ADC0_5, 0x03},
humlet 4:cd84739f7640 17 {P0_12, ADC0_6, 0x03},
humlet 4:cd84739f7640 18 {P0_13, ADC0_7, 0x03},
humlet 4:cd84739f7640 19 {NC , NC , 0 }
humlet 4:cd84739f7640 20 };
humlet 4:cd84739f7640 21
Sissors 7:965a2b0e477f 22 static int channel_usage[8] = {0,0,0,0,0,0,0,0};
humlet 4:cd84739f7640 23
humlet 4:cd84739f7640 24 FastAnalogIn::FastAnalogIn(PinName pin, bool enabled)
humlet 4:cd84739f7640 25 {
humlet 4:cd84739f7640 26 ADCnumber = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
humlet 4:cd84739f7640 27 if (ADCnumber == (uint32_t)NC)
humlet 4:cd84739f7640 28 error("ADC pin mapping failed");
humlet 4:cd84739f7640 29 datareg = (uint32_t*) (&LPC_ADC->DR[ADCnumber]);
humlet 4:cd84739f7640 30
humlet 5:55274430c8df 31 wait_us(1000); // wait for a short while before trying to initialize the ADC afer a reset (needed for those global instantiations just before main)
humlet 4:cd84739f7640 32
humlet 4:cd84739f7640 33 // ensure power is turned on
humlet 4:cd84739f7640 34 LPC_SC->PCONP |= (1 << 12);
humlet 4:cd84739f7640 35
humlet 4:cd84739f7640 36 uint32_t PCLK = PeripheralClock;
humlet 4:cd84739f7640 37
humlet 4:cd84739f7640 38 // calculate minimum clock divider
humlet 4:cd84739f7640 39 // clkdiv = divider - 1
humlet 4:cd84739f7640 40 uint32_t MAX_ADC_CLK = 12400000;
humlet 4:cd84739f7640 41 uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1;
humlet 4:cd84739f7640 42 // Set the clkdiv
humlet 4:cd84739f7640 43 LPC_ADC->CR &= ~(255<<8);
humlet 4:cd84739f7640 44 LPC_ADC->CR |= clkdiv<<8;
humlet 4:cd84739f7640 45
humlet 4:cd84739f7640 46 //Enable ADC:
humlet 4:cd84739f7640 47 LPC_ADC->CR |= 1<<21;
humlet 4:cd84739f7640 48
humlet 4:cd84739f7640 49 //Enable burstmode, set start as zero
humlet 4:cd84739f7640 50 LPC_ADC->CR |= 1<<16;
humlet 4:cd84739f7640 51 LPC_ADC->CR &= ~(7<<24);
humlet 4:cd84739f7640 52
humlet 4:cd84739f7640 53 // must enable analog mode (ADMODE = 0) ... ??? just copied from official LPC408X analogin_api.c
humlet 4:cd84739f7640 54 __IO uint32_t *reg = (__IO uint32_t*) (LPC_IOCON_BASE + 4 * pin);
humlet 4:cd84739f7640 55 *reg &= ~(1 << 7);
humlet 4:cd84739f7640 56
humlet 4:cd84739f7640 57 //Map pins
humlet 4:cd84739f7640 58 pinmap_pinout(pin, PinMap_ADC);
humlet 4:cd84739f7640 59
humlet 4:cd84739f7640 60 //Enable channel
humlet 4:cd84739f7640 61 running = false;
humlet 4:cd84739f7640 62 enable(enabled);
humlet 4:cd84739f7640 63
humlet 4:cd84739f7640 64 }
humlet 4:cd84739f7640 65
humlet 4:cd84739f7640 66 void FastAnalogIn::enable(bool enabled)
humlet 4:cd84739f7640 67 {
humlet 4:cd84739f7640 68 //If currently not running
humlet 4:cd84739f7640 69 if (!running) {
humlet 4:cd84739f7640 70 if (enabled) {
humlet 4:cd84739f7640 71 //Enable the ADC channel
humlet 4:cd84739f7640 72 channel_usage[ADCnumber]++;
humlet 4:cd84739f7640 73 LPC_ADC->CR |= (1<<ADCnumber);
humlet 4:cd84739f7640 74 running = true;
humlet 4:cd84739f7640 75 } else
humlet 4:cd84739f7640 76 disable();
humlet 4:cd84739f7640 77 }
humlet 4:cd84739f7640 78 }
humlet 4:cd84739f7640 79
humlet 4:cd84739f7640 80 void FastAnalogIn::disable( void )
humlet 4:cd84739f7640 81 {
humlet 4:cd84739f7640 82 //If currently running
humlet 4:cd84739f7640 83 if (running) {
humlet 4:cd84739f7640 84 channel_usage[ADCnumber]--;
humlet 4:cd84739f7640 85
humlet 4:cd84739f7640 86 if (channel_usage[ADCnumber]==0)
humlet 4:cd84739f7640 87 LPC_ADC->CR &= ~(1<<ADCnumber);
humlet 4:cd84739f7640 88 }
humlet 4:cd84739f7640 89 running = false;
humlet 4:cd84739f7640 90 }
humlet 4:cd84739f7640 91
humlet 4:cd84739f7640 92 unsigned short FastAnalogIn::read_u16( void )
humlet 4:cd84739f7640 93 {
humlet 4:cd84739f7640 94 volatile unsigned int retval;
humlet 4:cd84739f7640 95 //If object is enabled return current value of datareg
humlet 4:cd84739f7640 96 if (running ){
humlet 4:cd84739f7640 97 retval = *datareg;
humlet 4:cd84739f7640 98 //If it isn't running, enable it and wait until new value is written to datareg
humlet 4:cd84739f7640 99 }else {
humlet 4:cd84739f7640 100 //Force a read to clear done bit, enable the ADC channel
humlet 4:cd84739f7640 101 retval = *datareg;
humlet 4:cd84739f7640 102 enable();
humlet 4:cd84739f7640 103 //Wait until it is converted
humlet 4:cd84739f7640 104 while(1) {
humlet 4:cd84739f7640 105 wait_us(1);
humlet 4:cd84739f7640 106 retval = *datareg;
humlet 4:cd84739f7640 107 if ((retval>>31) == 1)
humlet 4:cd84739f7640 108 break;
humlet 4:cd84739f7640 109 }
humlet 4:cd84739f7640 110 //Do a second conversion since first one always fails for some reason
humlet 4:cd84739f7640 111 while(1) {
humlet 4:cd84739f7640 112 wait_us(1);
humlet 4:cd84739f7640 113 retval = *datareg;
humlet 4:cd84739f7640 114 if ((retval>>31) == 1)
humlet 4:cd84739f7640 115 break;
humlet 4:cd84739f7640 116 }
humlet 4:cd84739f7640 117 //Disable again
humlet 4:cd84739f7640 118 disable();
humlet 4:cd84739f7640 119 }
humlet 4:cd84739f7640 120
humlet 4:cd84739f7640 121 //Do same thing as standard mbed lib, unused bit 0-3, replicate 4-7 in it
humlet 4:cd84739f7640 122 retval &= ~0xFFFF000F;
humlet 4:cd84739f7640 123 retval |= (retval >> 8) & 0x000F;
humlet 4:cd84739f7640 124 return retval;
humlet 4:cd84739f7640 125
humlet 4:cd84739f7640 126 }
humlet 4:cd84739f7640 127 #endif //defined TARGET_LPC408X
Sissors 7:965a2b0e477f 128