defines changed from TARGET_LPC1768 to TARGET_LPC176X to support LPC1769 target
Fork of FastAnalogIn by
FastAnalogIn.cpp@0:c2a7b899e6c7, 2013-05-09 (annotated)
- Committer:
- Sissors
- Date:
- Thu May 09 17:46:32 2013 +0000
- Revision:
- 0:c2a7b899e6c7
- Child:
- 1:575f4d2d6e9c
v0.1
;
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
Sissors | 0:c2a7b899e6c7 | 1 | #include "FastAnalogIn.h" |
Sissors | 0:c2a7b899e6c7 | 2 | static inline int div_round_up(int x, int y) |
Sissors | 0:c2a7b899e6c7 | 3 | { |
Sissors | 0:c2a7b899e6c7 | 4 | return (x + (y - 1)) / y; |
Sissors | 0:c2a7b899e6c7 | 5 | } |
Sissors | 0:c2a7b899e6c7 | 6 | |
Sissors | 0:c2a7b899e6c7 | 7 | const PinMap FastAnalogIn::PinMap_ADC[] = { |
Sissors | 0:c2a7b899e6c7 | 8 | {P0_23, ADC0_0, 1}, |
Sissors | 0:c2a7b899e6c7 | 9 | {P0_24, ADC0_1, 1}, |
Sissors | 0:c2a7b899e6c7 | 10 | {P0_25, ADC0_2, 1}, |
Sissors | 0:c2a7b899e6c7 | 11 | {P0_26, ADC0_3, 1}, |
Sissors | 0:c2a7b899e6c7 | 12 | {P1_30, ADC0_4, 3}, |
Sissors | 0:c2a7b899e6c7 | 13 | {P1_31, ADC0_5, 3}, |
Sissors | 0:c2a7b899e6c7 | 14 | {P0_2, ADC0_7, 2}, |
Sissors | 0:c2a7b899e6c7 | 15 | {P0_3, ADC0_6, 2}, |
Sissors | 0:c2a7b899e6c7 | 16 | {NC, NC, 0} |
Sissors | 0:c2a7b899e6c7 | 17 | }; |
Sissors | 0:c2a7b899e6c7 | 18 | |
Sissors | 0:c2a7b899e6c7 | 19 | int FastAnalogIn::channel_usage[] = {0}; |
Sissors | 0:c2a7b899e6c7 | 20 | |
Sissors | 0:c2a7b899e6c7 | 21 | |
Sissors | 0:c2a7b899e6c7 | 22 | FastAnalogIn::FastAnalogIn(PinName pin, bool enabled) |
Sissors | 0:c2a7b899e6c7 | 23 | { |
Sissors | 0:c2a7b899e6c7 | 24 | ADCnumber = (ADCName)pinmap_peripheral(pin, PinMap_ADC); |
Sissors | 0:c2a7b899e6c7 | 25 | if (ADCnumber == (uint32_t)NC) |
Sissors | 0:c2a7b899e6c7 | 26 | error("ADC pin mapping failed"); |
Sissors | 0:c2a7b899e6c7 | 27 | datareg = (uint32_t*) (&LPC_ADC->ADDR0 + ADCnumber); |
Sissors | 0:c2a7b899e6c7 | 28 | |
Sissors | 0:c2a7b899e6c7 | 29 | // ensure power is turned on |
Sissors | 0:c2a7b899e6c7 | 30 | LPC_SC->PCONP |= (1 << 12); |
Sissors | 0:c2a7b899e6c7 | 31 | // set PCLK of ADC to /1 |
Sissors | 0:c2a7b899e6c7 | 32 | LPC_SC->PCLKSEL0 &= ~(0x3 << 24); |
Sissors | 0:c2a7b899e6c7 | 33 | LPC_SC->PCLKSEL0 |= (0x1 << 24); |
Sissors | 0:c2a7b899e6c7 | 34 | uint32_t PCLK = SystemCoreClock; |
Sissors | 0:c2a7b899e6c7 | 35 | |
Sissors | 0:c2a7b899e6c7 | 36 | // calculate minimum clock divider |
Sissors | 0:c2a7b899e6c7 | 37 | // clkdiv = divider - 1 |
Sissors | 0:c2a7b899e6c7 | 38 | uint32_t MAX_ADC_CLK = 13000000; |
Sissors | 0:c2a7b899e6c7 | 39 | uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1; |
Sissors | 0:c2a7b899e6c7 | 40 | // Set the clkdiv |
Sissors | 0:c2a7b899e6c7 | 41 | LPC_ADC->ADCR &= ~(255<<8); |
Sissors | 0:c2a7b899e6c7 | 42 | LPC_ADC->ADCR |= clkdiv<<8; |
Sissors | 0:c2a7b899e6c7 | 43 | |
Sissors | 0:c2a7b899e6c7 | 44 | //Enable ADC: |
Sissors | 0:c2a7b899e6c7 | 45 | LPC_ADC->ADCR |= 1<<21; |
Sissors | 0:c2a7b899e6c7 | 46 | |
Sissors | 0:c2a7b899e6c7 | 47 | //Enable burstmode, set start as zero |
Sissors | 0:c2a7b899e6c7 | 48 | LPC_ADC->ADCR |= 1<<16; |
Sissors | 0:c2a7b899e6c7 | 49 | LPC_ADC->ADCR &= ~(7<<24); |
Sissors | 0:c2a7b899e6c7 | 50 | |
Sissors | 0:c2a7b899e6c7 | 51 | //Map pins |
Sissors | 0:c2a7b899e6c7 | 52 | pinmap_pinout(pin, PinMap_ADC); |
Sissors | 0:c2a7b899e6c7 | 53 | |
Sissors | 0:c2a7b899e6c7 | 54 | //Enable channel |
Sissors | 0:c2a7b899e6c7 | 55 | running = false; |
Sissors | 0:c2a7b899e6c7 | 56 | enable(enabled); |
Sissors | 0:c2a7b899e6c7 | 57 | |
Sissors | 0:c2a7b899e6c7 | 58 | }; |
Sissors | 0:c2a7b899e6c7 | 59 | |
Sissors | 0:c2a7b899e6c7 | 60 | FastAnalogIn::~FastAnalogIn(void) |
Sissors | 0:c2a7b899e6c7 | 61 | { |
Sissors | 0:c2a7b899e6c7 | 62 | disable(); |
Sissors | 0:c2a7b899e6c7 | 63 | } |
Sissors | 0:c2a7b899e6c7 | 64 | |
Sissors | 0:c2a7b899e6c7 | 65 | |
Sissors | 0:c2a7b899e6c7 | 66 | void FastAnalogIn::enable(bool enabled) |
Sissors | 0:c2a7b899e6c7 | 67 | { |
Sissors | 0:c2a7b899e6c7 | 68 | //If currently not running |
Sissors | 0:c2a7b899e6c7 | 69 | if (!running) { |
Sissors | 0:c2a7b899e6c7 | 70 | if (enabled) { |
Sissors | 0:c2a7b899e6c7 | 71 | //Enable the ADC channel |
Sissors | 0:c2a7b899e6c7 | 72 | channel_usage[ADCnumber]++; |
Sissors | 0:c2a7b899e6c7 | 73 | LPC_ADC->ADCR |= (1<<ADCnumber); |
Sissors | 0:c2a7b899e6c7 | 74 | running = true; |
Sissors | 0:c2a7b899e6c7 | 75 | } else |
Sissors | 0:c2a7b899e6c7 | 76 | disable(); |
Sissors | 0:c2a7b899e6c7 | 77 | } |
Sissors | 0:c2a7b899e6c7 | 78 | }; |
Sissors | 0:c2a7b899e6c7 | 79 | |
Sissors | 0:c2a7b899e6c7 | 80 | void FastAnalogIn::disable( void ) |
Sissors | 0:c2a7b899e6c7 | 81 | { |
Sissors | 0:c2a7b899e6c7 | 82 | //If currently running |
Sissors | 0:c2a7b899e6c7 | 83 | if (running) { |
Sissors | 0:c2a7b899e6c7 | 84 | channel_usage[ADCnumber]--; |
Sissors | 0:c2a7b899e6c7 | 85 | |
Sissors | 0:c2a7b899e6c7 | 86 | if (channel_usage[ADCnumber]==0) |
Sissors | 0:c2a7b899e6c7 | 87 | LPC_ADC->ADCR &= ~(1<<ADCnumber); |
Sissors | 0:c2a7b899e6c7 | 88 | } |
Sissors | 0:c2a7b899e6c7 | 89 | running = false; |
Sissors | 0:c2a7b899e6c7 | 90 | }; |
Sissors | 0:c2a7b899e6c7 | 91 | |
Sissors | 0:c2a7b899e6c7 | 92 | unsigned short FastAnalogIn::read_u16( void ) |
Sissors | 0:c2a7b899e6c7 | 93 | { |
Sissors | 0:c2a7b899e6c7 | 94 | //If object is enabled return current value of datareg |
Sissors | 0:c2a7b899e6c7 | 95 | if (running ) { |
Sissors | 0:c2a7b899e6c7 | 96 | unsigned int retval = *datareg; |
Sissors | 0:c2a7b899e6c7 | 97 | retval = retval >> 4; |
Sissors | 0:c2a7b899e6c7 | 98 | retval = retval & 4095; |
Sissors | 0:c2a7b899e6c7 | 99 | return retval; |
Sissors | 0:c2a7b899e6c7 | 100 | } |
Sissors | 0:c2a7b899e6c7 | 101 | //If it isn't running, enable it and wait until new value is written to datareg |
Sissors | 0:c2a7b899e6c7 | 102 | else { |
Sissors | 0:c2a7b899e6c7 | 103 | //Force a read to clear done bit, enable the ADC channel |
Sissors | 0:c2a7b899e6c7 | 104 | volatile unsigned int retval = *datareg; |
Sissors | 0:c2a7b899e6c7 | 105 | enable(); |
Sissors | 0:c2a7b899e6c7 | 106 | //Wait until it is converted |
Sissors | 0:c2a7b899e6c7 | 107 | while(1) { |
Sissors | 0:c2a7b899e6c7 | 108 | wait_us(1); |
Sissors | 0:c2a7b899e6c7 | 109 | retval = *datareg; |
Sissors | 0:c2a7b899e6c7 | 110 | if ((retval>>31) == 1) |
Sissors | 0:c2a7b899e6c7 | 111 | break; |
Sissors | 0:c2a7b899e6c7 | 112 | } |
Sissors | 0:c2a7b899e6c7 | 113 | |
Sissors | 0:c2a7b899e6c7 | 114 | //Do a second conversion since first one always fails for some reason |
Sissors | 0:c2a7b899e6c7 | 115 | while(1) { |
Sissors | 0:c2a7b899e6c7 | 116 | wait_us(1); |
Sissors | 0:c2a7b899e6c7 | 117 | retval = *datareg; |
Sissors | 0:c2a7b899e6c7 | 118 | if ((retval>>31) == 1) |
Sissors | 0:c2a7b899e6c7 | 119 | break; |
Sissors | 0:c2a7b899e6c7 | 120 | } |
Sissors | 0:c2a7b899e6c7 | 121 | |
Sissors | 0:c2a7b899e6c7 | 122 | //Disable again |
Sissors | 0:c2a7b899e6c7 | 123 | disable(); |
Sissors | 0:c2a7b899e6c7 | 124 | retval = retval >> 4; |
Sissors | 0:c2a7b899e6c7 | 125 | retval = retval & 4095; |
Sissors | 0:c2a7b899e6c7 | 126 | return retval; |
Sissors | 0:c2a7b899e6c7 | 127 | } |
Sissors | 0:c2a7b899e6c7 | 128 | |
Sissors | 0:c2a7b899e6c7 | 129 | |
Sissors | 0:c2a7b899e6c7 | 130 | }; |
Sissors | 0:c2a7b899e6c7 | 131 | |
Sissors | 0:c2a7b899e6c7 | 132 | float FastAnalogIn::read( void ) |
Sissors | 0:c2a7b899e6c7 | 133 | { |
Sissors | 0:c2a7b899e6c7 | 134 | unsigned short value = read_u16(); |
Sissors | 0:c2a7b899e6c7 | 135 | return (float)value/4095; |
Sissors | 0:c2a7b899e6c7 | 136 | } |