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. This slightly modified version allows NC pins.
Dependents: Pinscape_Controller
Fork of FastAnalogIn by
Diff: FastAnalogIn_KLXX_K20D50M.cpp
- Revision:
- 9:31184aa1449c
- Child:
- 11:234c5cd2b8de
diff -r 68082fdde730 -r 31184aa1449c FastAnalogIn_KLXX_K20D50M.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/FastAnalogIn_KLXX_K20D50M.cpp Sat Jul 12 10:39:37 2014 +0000 @@ -0,0 +1,114 @@ +#if defined(TARGET_KLXX) || defined(TARGET_K20D50M) + +#include "FastAnalogIn.h" +#include "clk_freqs.h" + +#define MAX_FADC 6000000 +#define CHANNELS_A_SHIFT 5 + +#ifdef TARGET_K20D50M +static const PinMap PinMap_ADC[] = { + {PTC2, ADC0_SE4b, 0}, + {PTD1, ADC0_SE5b, 0}, + {PTD5, ADC0_SE6b, 0}, + {PTD6, ADC0_SE7b, 0}, + {PTB0, ADC0_SE8, 0}, + {PTB1, ADC0_SE9, 0}, + {PTB2, ADC0_SE12, 0}, + {PTB3, ADC0_SE13, 0}, + {PTC0, ADC0_SE14, 0}, + {PTC1, ADC0_SE15, 0}, + {NC, NC, 0} +}; +#endif + +FastAnalogIn::FastAnalogIn(PinName pin, bool enabled) +{ + ADCnumber = (ADCName)pinmap_peripheral(pin, PinMap_ADC); + if (ADCnumber == (ADCName)NC) { + error("ADC pin mapping failed"); + } + + SIM->SCGC6 |= SIM_SCGC6_ADC0_MASK; + + uint32_t port = (uint32_t)pin >> PORT_SHIFT; + SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port); + + uint32_t cfg2_muxsel = ADC_CFG2_MUXSEL_MASK; + if (ADCnumber & (1 << CHANNELS_A_SHIFT)) { + cfg2_muxsel = 0; + } + + // bus clk + uint32_t PCLK = bus_frequency(); + uint32_t clkdiv; + for (clkdiv = 0; clkdiv < 4; clkdiv++) { + if ((PCLK >> clkdiv) <= MAX_FADC) + break; + } + if (clkdiv == 4) //Set max div + clkdiv = 0x7; + + ADC0->SC1[1] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT)); + + ADC0->CFG1 = ADC_CFG1_ADIV(clkdiv & 0x3) // Clock Divide Select: (Input Clock)/8 + | ADC_CFG1_MODE(3) // (16)bits Resolution + | ADC_CFG1_ADICLK(clkdiv >> 2); // Input Clock: (Bus Clock)/2 + + ADC0->CFG2 = cfg2_muxsel // ADxxb or ADxxa channels + | ADC_CFG2_ADACKEN_MASK // Asynchronous Clock Output Enable + | ADC_CFG2_ADHSC_MASK; // High-Speed Configuration + + ADC0->SC2 = ADC_SC2_REFSEL(0); // Default Voltage Reference + + pinmap_pinout(pin, PinMap_ADC); + + //Enable channel + running = false; + enable(enabled); +} + +void FastAnalogIn::enable(bool enabled) +{ + //If currently not running + if (!running) { + if (enabled) { + //Enable the ADC channel + ADC0->SC3 |= ADC_SC3_ADCO_MASK; // Enable continuous conversion + ADC0->SC1[0] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT)); //Start conversion + running = true; + } else + disable(); + } +} + +void FastAnalogIn::disable( void ) +{ + //If currently running + if (running) { + ADC0->SC3 &= ~ADC_SC3_ADCO_MASK; // Disable continuous conversion + } + running = false; +} + +uint16_t FastAnalogIn::read_u16() +{ + if (!running) + { + // start conversion + ADC0->SC1[0] = ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT)); + // Wait Conversion Complete + while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) != ADC_SC1_COCO_MASK); + } + if(running && ((ADC0->SC1[0]&ADC_SC1_ADCH_MASK) != (ADC_SC1_ADCH(ADCnumber & ~(1 << CHANNELS_A_SHIFT))))) + { + running = false; + enable(); + while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) != ADC_SC1_COCO_MASK); + } + // Return value + return (uint16_t)ADC0->R[0]; +} + +#endif //defined TARGET_KLXX +