Helmut Schmücker / FastAnalogIn

Class similar to AnalogIn that uses burst mode to run continious background conversions so when the input is read, the last value can immediatly be returned.

Fork of FastAnalogIn by Erik -

Obsolete!

Has been already merged with Erik's original repository => take the original!

  • Added support for LPC4088.
  • Fixed linker error (missing definition of static member "channel_usage")

FastAnalogIn_KLXX.cpp@5:55274430c8df, 2014-04-21 (annotated)

Committer:
humlet
Date:
Mon Apr 21 07:17:39 2014 +0000
Revision:
5:55274430c8df
Parent:
3:a9b753c25073 
* minor docu changes; * added definition of "channel_usage" also to KLXX-implementation

Who changed what in which revision?

UserRevisionLine numberNew contents of line
frankvnk 2:9b61d0792927 1 #ifdef TARGET_KLXX
frankvnk 2:9b61d0792927 2
frankvnk 2:9b61d0792927 3 #include "FastAnalogIn.h"
frankvnk 2:9b61d0792927 4 #include "clk_freqs.h"
frankvnk 2:9b61d0792927 5
frankvnk 2:9b61d0792927 6 #define MAX_FADC 6000000
frankvnk 2:9b61d0792927 7 #define CHANNELS_A_SHIFT 5
frankvnk 2:9b61d0792927 8
humlet 5:55274430c8df 9 int FastAnalogIn::channel_usage[8] = {0,0,0,0,0,0,0,0};
humlet 5:55274430c8df 10
frankvnk 2:9b61d0792927 11 FastAnalogIn::FastAnalogIn(PinName pin, bool enabled)
frankvnk 2:9b61d0792927 12 {
frankvnk 2:9b61d0792927 13 ADCnumber = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
frankvnk 2:9b61d0792927 14 if (ADCnumber == (ADCName)NC) {
frankvnk 2:9b61d0792927 15 error("ADC pin mapping failed");
frankvnk 2:9b61d0792927 16 }
frankvnk 2:9b61d0792927 17
frankvnk 2:9b61d0792927 18 SIM->SCGC6 |= SIM_SCGC6_ADC0_MASK;
frankvnk 2:9b61d0792927 19
frankvnk 2:9b61d0792927 20 uint32_t port = (uint32_t)pin >> PORT_SHIFT;
frankvnk 2:9b61d0792927 21 SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
frankvnk 2:9b61d0792927 22
frankvnk 2:9b61d0792927 23 uint32_t cfg2_muxsel = ADC_CFG2_MUXSEL_MASK;
frankvnk 2:9b61d0792927 24 if (ADCnumber & (1 << CHANNELS_A_SHIFT)) {
frankvnk 2:9b61d0792927 25 cfg2_muxsel = 0;
frankvnk 2:9b61d0792927 26 }
frankvnk 2:9b61d0792927 27
frankvnk 2:9b61d0792927 28 // bus clk
frankvnk 2:9b61d0792927 29 uint32_t PCLK = bus_frequency();
frankvnk 2:9b61d0792927 30 uint32_t clkdiv;
frankvnk 2:9b61d0792927 31 for (clkdiv = 0; clkdiv < 4; clkdiv++) {
frankvnk 2:9b61d0792927 32 if ((PCLK >> clkdiv) <= MAX_FADC)
frankvnk 2:9b61d0792927 33 break;
frankvnk 2:9b61d0792927 34 }
frankvnk 2:9b61d0792927 35 if (clkdiv == 4) //Set max div
frankvnk 2:9b61d0792927 36 clkdiv = 0x7;
frankvnk 2:9b61d0792927 37
frankvnk 2:9b61d0792927 38 ADC0->SC1[1] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT));
frankvnk 2:9b61d0792927 39
frankvnk 2:9b61d0792927 40 ADC0->CFG1 = ADC_CFG1_ADIV(clkdiv & 0x3) // Clock Divide Select: (Input Clock)/8
frankvnk 2:9b61d0792927 41 | ADC_CFG1_MODE(3) // (16)bits Resolution
frankvnk 2:9b61d0792927 42 | ADC_CFG1_ADICLK(clkdiv >> 2); // Input Clock: (Bus Clock)/2
frankvnk 2:9b61d0792927 43
frankvnk 2:9b61d0792927 44 ADC0->CFG2 = cfg2_muxsel // ADxxb or ADxxa channels
frankvnk 2:9b61d0792927 45 | ADC_CFG2_ADACKEN_MASK // Asynchronous Clock Output Enable
frankvnk 2:9b61d0792927 46 | ADC_CFG2_ADHSC_MASK; // High-Speed Configuration
frankvnk 2:9b61d0792927 47
frankvnk 2:9b61d0792927 48 ADC0->SC2 = ADC_SC2_REFSEL(0); // Default Voltage Reference
frankvnk 2:9b61d0792927 49
frankvnk 2:9b61d0792927 50 pinmap_pinout(pin, PinMap_ADC);
frankvnk 2:9b61d0792927 51
frankvnk 2:9b61d0792927 52 //Enable channel
frankvnk 2:9b61d0792927 53 running = false;
frankvnk 2:9b61d0792927 54 enable(enabled);
frankvnk 2:9b61d0792927 55 }
frankvnk 2:9b61d0792927 56
frankvnk 2:9b61d0792927 57 void FastAnalogIn::enable(bool enabled)
frankvnk 2:9b61d0792927 58 {
frankvnk 2:9b61d0792927 59 //If currently not running
frankvnk 2:9b61d0792927 60 if (!running) {
frankvnk 2:9b61d0792927 61 if (enabled) {
frankvnk 2:9b61d0792927 62 //Enable the ADC channel
frankvnk 2:9b61d0792927 63 ADC0->SC3 |= ADC_SC3_ADCO_MASK; // Enable continuous conversion
frankvnk 2:9b61d0792927 64 ADC0->SC1[0] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT)); //Start conversion
frankvnk 2:9b61d0792927 65 running = true;
frankvnk 2:9b61d0792927 66 } else
frankvnk 2:9b61d0792927 67 disable();
frankvnk 2:9b61d0792927 68 }
frankvnk 2:9b61d0792927 69 }
frankvnk 2:9b61d0792927 70
frankvnk 2:9b61d0792927 71 void FastAnalogIn::disable( void )
frankvnk 2:9b61d0792927 72 {
frankvnk 2:9b61d0792927 73 //If currently running
frankvnk 2:9b61d0792927 74 if (running) {
frankvnk 2:9b61d0792927 75 ADC0->SC3 &= ~ADC_SC3_ADCO_MASK; // Disable continuous conversion
frankvnk 2:9b61d0792927 76 }
frankvnk 2:9b61d0792927 77 running = false;
frankvnk 2:9b61d0792927 78 }
frankvnk 2:9b61d0792927 79
frankvnk 2:9b61d0792927 80 uint16_t FastAnalogIn::read_u16()
frankvnk 2:9b61d0792927 81 {
frankvnk 2:9b61d0792927 82 if (!running)
frankvnk 2:9b61d0792927 83 {
frankvnk 2:9b61d0792927 84 // start conversion
frankvnk 2:9b61d0792927 85 ADC0->SC1[0] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT));
frankvnk 2:9b61d0792927 86 // Wait Conversion Complete
frankvnk 2:9b61d0792927 87 while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) != ADC_SC1_COCO_MASK);
frankvnk 2:9b61d0792927 88 }
frankvnk 2:9b61d0792927 89 if(running && ((ADC0->SC1[0]&ADC_SC1_ADCH_MASK) != (ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT)))))
frankvnk 2:9b61d0792927 90 {
frankvnk 2:9b61d0792927 91 running = false;
frankvnk 2:9b61d0792927 92 enable();
frankvnk 2:9b61d0792927 93 while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) != ADC_SC1_COCO_MASK);
frankvnk 2:9b61d0792927 94 }
frankvnk 2:9b61d0792927 95 // Return value
frankvnk 2:9b61d0792927 96 return (uint16_t)ADC0->R[0];
frankvnk 2:9b61d0792927 97 }
frankvnk 2:9b61d0792927 98
frankvnk 2:9b61d0792927 99 #endif //defined TARGET_KLXX
frankvnk 2:9b61d0792927 100