Mark Uckermann / NbAnalogIn

Fast AnalogIn module which asks for a single non blocking reading and causes and interrupt when done.

NbAnalogIn.cpp@1:2666729acca1, 2017-04-02 (annotated)

Committer:
dontknowhow
Date:
Sun Apr 02 11:16:24 2017 +0000
Revision:
1:2666729acca1
Parent:
0:058d32b78e5d
Child:
2:336af413f75c
IRQ handlers in class

Who changed what in which revision?

UserRevisionLine numberNew contents of line
dontknowhow 0:058d32b78e5d 1 #include "NbAnalogIn.h"
dontknowhow 0:058d32b78e5d 2
dontknowhow 1:2666729acca1 3 static inline int pos_inc(int i) {
dontknowhow 1:2666729acca1 4
dontknowhow 1:2666729acca1 5 if (i < ADC_BUF_SIZE - 1) {
dontknowhow 1:2666729acca1 6 i++;
dontknowhow 1:2666729acca1 7 } else {
dontknowhow 1:2666729acca1 8 i = 0;
dontknowhow 1:2666729acca1 9 }
dontknowhow 1:2666729acca1 10 return i;
dontknowhow 1:2666729acca1 11 }
dontknowhow 1:2666729acca1 12
dontknowhow 1:2666729acca1 13 NbAnalogIn* NbAnalogIn::handlers[2] = {0};
dontknowhow 1:2666729acca1 14
dontknowhow 0:058d32b78e5d 15 NbAnalogIn::NbAnalogIn(){
dontknowhow 0:058d32b78e5d 16
dontknowhow 0:058d32b78e5d 17 NVIC_EnableIRQ(ADC_IRQn);
dontknowhow 1:2666729acca1 18 NVIC_SetVector(ADC_IRQn, (uint32_t)irq);
dontknowhow 1:2666729acca1 19
dontknowhow 1:2666729acca1 20 write_pos = 0; // next position to be written to
dontknowhow 1:2666729acca1 21 read_pos = 0; // next position to be read from
dontknowhow 1:2666729acca1 22
dontknowhow 1:2666729acca1 23 handlers[0] = this; // put a pointer to this object into the handlers array
dontknowhow 0:058d32b78e5d 24
dontknowhow 0:058d32b78e5d 25 LPC_SC->PCONP |= (1 << 12); // turn power for ADC on
dontknowhow 0:058d32b78e5d 26
dontknowhow 0:058d32b78e5d 27 // set peripheral clock registers to provide clock for ADC (bits 24 & 25)
dontknowhow 0:058d32b78e5d 28 // set to 00 for PCLK = CCLK
dontknowhow 0:058d32b78e5d 29 LPC_SC->PCLKSEL0 &= ~(0x3 << 24); // clear bits
dontknowhow 0:058d32b78e5d 30 LPC_SC->PCLKSEL0 |= (0x1 << 24); // set bits
dontknowhow 0:058d32b78e5d 31
dontknowhow 0:058d32b78e5d 32 //set P1.30 as AD0.4
dontknowhow 0:058d32b78e5d 33 LPC_PINCON->PINSEL3 |= (3<<28);
dontknowhow 0:058d32b78e5d 34
dontknowhow 0:058d32b78e5d 35
dontknowhow 0:058d32b78e5d 36 //Set PINMODE of AD0.4 as no pull-up/down resistors
dontknowhow 0:058d32b78e5d 37 LPC_PINCON->PINMODE3 &= ~(3<<28);
dontknowhow 0:058d32b78e5d 38 LPC_PINCON->PINMODE3 |= (2<<28);
dontknowhow 0:058d32b78e5d 39
dontknowhow 0:058d32b78e5d 40
dontknowhow 0:058d32b78e5d 41 /* set the A/D control register */
dontknowhow 0:058d32b78e5d 42
dontknowhow 0:058d32b78e5d 43 // select 4, clkdiv = 7, enable, don't start yet
dontknowhow 0:058d32b78e5d 44 LPC_ADC->ADCR = (1 << 4) | (7 << 8) | (1 << 21) | (0 << 24) ;
dontknowhow 0:058d32b78e5d 45
dontknowhow 1:2666729acca1 46
dontknowhow 1:2666729acca1 47
dontknowhow 0:058d32b78e5d 48
dontknowhow 0:058d32b78e5d 49 }
dontknowhow 0:058d32b78e5d 50
dontknowhow 0:058d32b78e5d 51
dontknowhow 0:058d32b78e5d 52 unsigned int NbAnalogIn::read() {
dontknowhow 0:058d32b78e5d 53
dontknowhow 0:058d32b78e5d 54 /* disable interrupts */
dontknowhow 0:058d32b78e5d 55 LPC_ADC->ADINTEN &= ~(1 << 4);
dontknowhow 0:058d32b78e5d 56 LPC_ADC->ADINTEN = 0;
dontknowhow 0:058d32b78e5d 57
dontknowhow 0:058d32b78e5d 58 LPC_ADC->ADCR |= (1 << 24) ; // start conversion
dontknowhow 0:058d32b78e5d 59
dontknowhow 0:058d32b78e5d 60 while((LPC_ADC->ADSTAT & (1<<4)) == 0);
dontknowhow 0:058d32b78e5d 61
dontknowhow 0:058d32b78e5d 62 return (unsigned int)((LPC_ADC->ADGDR >> 4) & 0xFFF);
dontknowhow 0:058d32b78e5d 63 }
dontknowhow 0:058d32b78e5d 64
dontknowhow 1:2666729acca1 65 void NbAnalogIn::triggerConv() {
dontknowhow 0:058d32b78e5d 66 /* enable interrupts */
dontknowhow 0:058d32b78e5d 67 LPC_ADC->ADINTEN = (1 << 4);
dontknowhow 0:058d32b78e5d 68
dontknowhow 0:058d32b78e5d 69 LPC_ADC->ADCR |= (1 << 24) ; // start conversion
dontknowhow 1:2666729acca1 70 }
dontknowhow 1:2666729acca1 71
dontknowhow 1:2666729acca1 72 // static interrupt handler
dontknowhow 1:2666729acca1 73 void NbAnalogIn::irq() {
dontknowhow 1:2666729acca1 74
dontknowhow 1:2666729acca1 75 int adc_result = (int)((LPC_ADC->ADGDR >> 4) & 0xFFF);
dontknowhow 1:2666729acca1 76 uint8_t channel = (uint8_t)((LPC_ADC->ADGDR >> 24) & 0x7);
dontknowhow 1:2666729acca1 77
dontknowhow 1:2666729acca1 78 /** for debug *///
dontknowhow 1:2666729acca1 79 static int count = 0;
dontknowhow 1:2666729acca1 80 adc_result = count++;
dontknowhow 1:2666729acca1 81 printf("NB! channel %d, result %d \n",channel, adc_result);
dontknowhow 1:2666729acca1 82
dontknowhow 1:2666729acca1 83
dontknowhow 1:2666729acca1 84 // call the right channel's handler
dontknowhow 1:2666729acca1 85 handlers[0]->handler(adc_result);
dontknowhow 1:2666729acca1 86
dontknowhow 1:2666729acca1 87
dontknowhow 1:2666729acca1 88 /* disable interrupt */
dontknowhow 1:2666729acca1 89 LPC_ADC->ADINTEN &= ~(1 << channel);
dontknowhow 1:2666729acca1 90 }
dontknowhow 1:2666729acca1 91
dontknowhow 1:2666729acca1 92 void NbAnalogIn::handler( int adc_result ) {
dontknowhow 1:2666729acca1 93
dontknowhow 1:2666729acca1 94
dontknowhow 1:2666729acca1 95 buffer[write_pos] = adc_result;
dontknowhow 1:2666729acca1 96
dontknowhow 1:2666729acca1 97 printf("ADC: %d written into pos %d \n",adc_result, write_pos);
dontknowhow 1:2666729acca1 98 write_pos = pos_inc( write_pos );
dontknowhow 1:2666729acca1 99
dontknowhow 1:2666729acca1 100 // loop around
dontknowhow 1:2666729acca1 101 if( write_pos == read_pos ) {
dontknowhow 1:2666729acca1 102 read_pos = pos_inc( read_pos ); // keep read position ahead of write position
dontknowhow 1:2666729acca1 103 printf("ADC: LOOP AROUND!!! incremented r \n");
dontknowhow 1:2666729acca1 104 }
dontknowhow 1:2666729acca1 105 printf("ADC: w=%d, r=%d \n", write_pos, read_pos);
dontknowhow 1:2666729acca1 106
dontknowhow 1:2666729acca1 107
dontknowhow 1:2666729acca1 108 }
dontknowhow 1:2666729acca1 109
dontknowhow 1:2666729acca1 110 bool NbAnalogIn::readable() {
dontknowhow 1:2666729acca1 111 return write_pos != read_pos;
dontknowhow 1:2666729acca1 112 }
dontknowhow 1:2666729acca1 113
dontknowhow 1:2666729acca1 114 int NbAnalogIn::readNb() {
dontknowhow 1:2666729acca1 115
dontknowhow 1:2666729acca1 116 while(write_pos == read_pos);
dontknowhow 1:2666729acca1 117
dontknowhow 1:2666729acca1 118 int result = buffer[read_pos];
dontknowhow 1:2666729acca1 119
dontknowhow 1:2666729acca1 120 printf("MAIN: read %d from pos %d\n",buffer[read_pos], read_pos );
dontknowhow 1:2666729acca1 121
dontknowhow 1:2666729acca1 122 read_pos = pos_inc( read_pos ); // increment reading position
dontknowhow 1:2666729acca1 123
dontknowhow 1:2666729acca1 124
dontknowhow 1:2666729acca1 125
dontknowhow 1:2666729acca1 126 return result;
dontknowhow 0:058d32b78e5d 127 }