Jared Baxter / Mbed 2 deprecated Impedance_Fast_Circuitry

Impedance Fast Circuitry Software

Dependencies:   mbed-dsp mbed

Fork of DSP_200kHz by Mazzeo Research Group

adc.cpp@40:bd6d8c35e822, 2015-01-30 (annotated)

Committer:
timmey9
Date:
Fri Jan 30 06:16:39 2015 +0000
Revision:
40:bd6d8c35e822
Parent:
39:82dc3daecf32
Child:
41:3e0623d81b9a
ADC and DMA working.  Start and stop of ADC/DMA is also working.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
timmey9 39:82dc3daecf32 1 #include "adc.h"
timmey9 40:bd6d8c35e822 2 #include "dma.h"
timmey9 40:bd6d8c35e822 3
timmey9 40:bd6d8c35e822 4 DigitalOut blah(LED_BLUE);
timmey9 40:bd6d8c35e822 5 DigitalOut toggle(PTC16);
timmey9 39:82dc3daecf32 6
timmey9 39:82dc3daecf32 7 void analog_initialization(PinName pin, Serial &pc)
timmey9 39:82dc3daecf32 8 {
timmey9 39:82dc3daecf32 9
timmey9 40:bd6d8c35e822 10
timmey9 39:82dc3daecf32 11 // Turn on the ADC0 and ADC1 clocks
timmey9 39:82dc3daecf32 12 SIM_SCGC6 |= SIM_SCGC6_ADC0_MASK;
timmey9 39:82dc3daecf32 13 SIM_SCGC3 |= SIM_SCGC3_ADC1_MASK;
timmey9 39:82dc3daecf32 14
timmey9 39:82dc3daecf32 15
timmey9 40:bd6d8c35e822 16 /*
timmey9 39:82dc3daecf32 17 // Configure System Integration Module for defaults as far as ADC
timmey9 39:82dc3daecf32 18 SIM_SOPT7 &= ~(SIM_SOPT7_ADC1ALTTRGEN_MASK | // selects PDB not ALT trigger
timmey9 39:82dc3daecf32 19 SIM_SOPT7_ADC1PRETRGSEL_MASK |
timmey9 39:82dc3daecf32 20 SIM_SOPT7_ADC0ALTTRGEN_MASK | // selects PDB not ALT trigger
timmey9 39:82dc3daecf32 21 SIM_SOPT7_ADC0ALTTRGEN_MASK) ;
timmey9 39:82dc3daecf32 22 SIM_SOPT7 = SIM_SOPT7_ADC0TRGSEL(0); // applies only in case of ALT trigger, in which case PDB external pin input trigger for ADC
timmey9 39:82dc3daecf32 23 SIM_SOPT7 = SIM_SOPT7_ADC1TRGSEL(0); // same for both ADCs
timmey9 40:bd6d8c35e822 24 */
timmey9 40:bd6d8c35e822 25
timmey9 40:bd6d8c35e822 26 // enable interrupt
timmey9 40:bd6d8c35e822 27 ADC0_SC1A |= ADC_SC1_AIEN_MASK;
timmey9 39:82dc3daecf32 28
timmey9 39:82dc3daecf32 29 // enable the DMA
timmey9 39:82dc3daecf32 30 ADC0->SC2 |= ADC_SC2_DMAEN_MASK;
timmey9 39:82dc3daecf32 31 //ADC1->SC2 |= ADC_SC2_DMAEN_MASK;
timmey9 39:82dc3daecf32 32
timmey9 39:82dc3daecf32 33 // calibrate ADC
timmey9 39:82dc3daecf32 34 ADC0->SC3 = 0; // Reset SC3
timmey9 39:82dc3daecf32 35 //ADC1->SC3 = 0; // Reset SC3
timmey9 39:82dc3daecf32 36 /*do {
timmey9 39:82dc3daecf32 37 ADC0->SC3 |= (1<<7); // start calibration
timmey9 39:82dc3daecf32 38 while(ADC0->SC3&(1<<7)) {} // wait for calibration to complete
timmey9 39:82dc3daecf32 39 if((ADC0->SC3)&(1<<6)) pc.printf("Calibration Failed\r\n");
timmey9 39:82dc3daecf32 40 } while(ADC0->SC3&(1<<6));
timmey9 39:82dc3daecf32 41 */ // the calibration may be failing because ADC0_SC2 has the Vref set to external pins
timmey9 39:82dc3daecf32 42
timmey9 39:82dc3daecf32 43 ADC0->CFG1 |= ADC_CFG1_ADLPC_MASK; // high power mode for faster frequencies
timmey9 39:82dc3daecf32 44
timmey9 39:82dc3daecf32 45 ADCName adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
timmey9 39:82dc3daecf32 46 uint32_t instance = adc >> ADC_INSTANCE_SHIFT;
timmey9 39:82dc3daecf32 47 clock_manager_set_gate(kClockModuleADC, instance, true);
timmey9 39:82dc3daecf32 48 uint32_t bus_clock;
timmey9 39:82dc3daecf32 49 clock_manager_get_frequency(kBusClock, &bus_clock);
timmey9 39:82dc3daecf32 50 uint32_t clkdiv;
timmey9 39:82dc3daecf32 51 for (clkdiv = 0; clkdiv < 4; clkdiv++) {
timmey9 39:82dc3daecf32 52 if ((bus_clock >> clkdiv) <= MAX_FADC)
timmey9 39:82dc3daecf32 53 break;
timmey9 39:82dc3daecf32 54 }
timmey9 39:82dc3daecf32 55 if (clkdiv == 4) {
timmey9 39:82dc3daecf32 56 clkdiv = 0x7; //Set max div
timmey9 39:82dc3daecf32 57 }
timmey9 39:82dc3daecf32 58 // adc is enabled/triggered when reading.
timmey9 39:82dc3daecf32 59 adc_hal_set_clock_source_mode(instance, (adc_clock_source_mode_t)(clkdiv >> 2));
timmey9 39:82dc3daecf32 60 adc_hal_set_clock_divider_mode(instance, (adc_clock_divider_mode_t)(clkdiv & 0x3));
timmey9 39:82dc3daecf32 61 adc_hal_set_reference_voltage_mode(instance, kAdcVoltageVref);
timmey9 39:82dc3daecf32 62 adc_hal_set_resolution_mode(instance, kAdcSingleDiff16);
timmey9 40:bd6d8c35e822 63 adc_hal_configure_continuous_conversion(instance, true); // true=continuous conversion mode, false = single conversion mode
timmey9 40:bd6d8c35e822 64 adc_hal_configure_hw_trigger(instance, false); // true=hw trigger, false=sw trigger
timmey9 39:82dc3daecf32 65 adc_hal_configure_hw_average(instance, false);
timmey9 39:82dc3daecf32 66 adc_hal_set_hw_average_mode(instance, kAdcHwAverageCount4);
timmey9 39:82dc3daecf32 67 adc_hal_set_group_mux(instance, kAdcChannelMuxB); // only B channels are avail
timmey9 39:82dc3daecf32 68
timmey9 39:82dc3daecf32 69 pinmap_pinout(pin, PinMap_ADC);
timmey9 39:82dc3daecf32 70
timmey9 39:82dc3daecf32 71 pc.printf("ADC0_SC1a: %08x\r\n",ADC0_SC1A); // module disabled
timmey9 39:82dc3daecf32 72 pc.printf("ADC0_SC1b: %08x\r\n",ADC0_SC1B); // module disabled
timmey9 39:82dc3daecf32 73 pc.printf("ADC0_CFG1: %08x\r\n",ADC0_CFG1); // alternate clock2 selected, 16-bit 2's complement selected, short sample time, clock divide ration is input/8, low power mode selected
timmey9 39:82dc3daecf32 74 pc.printf("ADC0_CFG2: %08x\r\n",ADC0_CFG2); // ADxxa channels selected
timmey9 39:82dc3daecf32 75 pc.printf("ADC0_RA: %08x\r\n",ADC0_RA);
timmey9 39:82dc3daecf32 76 pc.printf("ADC0_RB: %08x\r\n",ADC0_RB);
timmey9 39:82dc3daecf32 77 pc.printf("ADC0_SC2: %08x\r\n",ADC0_SC2); // hw trigger and dma enabled. Compare function disabled and Vref set to external pin
timmey9 39:82dc3daecf32 78 pc.printf("ADC0_SC3: %08x\r\n\n",ADC0_SC3);
timmey9 40:bd6d8c35e822 79
timmey9 40:bd6d8c35e822 80 // Enable the ISR vector
timmey9 40:bd6d8c35e822 81 NVIC_SetVector (ADC0_IRQn, (uint32_t)&ADC0_IRQHandler);
timmey9 40:bd6d8c35e822 82 NVIC_EnableIRQ(ADC0_IRQn);
timmey9 40:bd6d8c35e822 83 }
timmey9 40:bd6d8c35e822 84
timmey9 40:bd6d8c35e822 85 void start_adc() {
timmey9 40:bd6d8c35e822 86 // reset DMA
timmey9 40:bd6d8c35e822 87 //reset_dma();
timmey9 40:bd6d8c35e822 88 dma_init(100);
timmey9 40:bd6d8c35e822 89
timmey9 40:bd6d8c35e822 90 // set ADC to continuous mode
timmey9 40:bd6d8c35e822 91 ADC0_SC3 |= ADC_SC3_ADCO_MASK;
timmey9 40:bd6d8c35e822 92
timmey9 40:bd6d8c35e822 93 // start ADC conversion (SW trigger)
timmey9 40:bd6d8c35e822 94 BW_ADC_SC1n_ADCH(0, 0, kAdcChannel12); // This corresponds to starting an ADC conversion on channel 12 of ADC 0 - which is A0 (PTB2)
timmey9 40:bd6d8c35e822 95 //BW_ADC_SC1n_ADCH(1, 0, kAdcChannel14); // This corresponds to starting an ADC conversion on channel 14 of ADC 1 - which is A2 (PTB10)
timmey9 40:bd6d8c35e822 96 }
timmey9 40:bd6d8c35e822 97
timmey9 40:bd6d8c35e822 98 void stop_adc() {
timmey9 40:bd6d8c35e822 99 ADC0_SC3 &= ~ADC_SC3_ADCO_MASK; // set to single conversion mode effectively stopping the ADC
timmey9 40:bd6d8c35e822 100 }
timmey9 40:bd6d8c35e822 101
timmey9 40:bd6d8c35e822 102 void ADC0_IRQHandler() {
timmey9 40:bd6d8c35e822 103 blah = !blah;
timmey9 39:82dc3daecf32 104 }