init
This commit is contained in:
r4
commit
382d659d4d
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/* Wiring:
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SD | Nano
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______________________
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D0 (DO) | D12 (MISO)
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VSS | GND
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CLK | D13 (SCK)
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VDD | 3V3
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CMD (DI) | D11 (MOSI)
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D3 (CS) | D10 (SS)
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SD pin D3 is the chip select pin (must be set manually in pin_ss).
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*/
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#include <avr/io.h>
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#include <avr/interrupt.h>
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#include <SPI.h>
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#include <SD.h>
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static int serial_putch(char c, FILE *f) {
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(void)f;
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return Serial.write(c) == 1 ? 0 : 1;
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}
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static int serial_getch(FILE *f) {
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(void)f;
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while(Serial.available() == 0);
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return Serial.read();
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}
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static FILE serial_in_out;
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static void setup_serial_in_out() {
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fdev_setup_stream(&serial_in_out, serial_putch, serial_getch, _FDEV_SETUP_RW);
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stdout = stdin = stderr = &serial_in_out;
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}
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//#define DEBUG_RECORDING
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#define SAMPLE_MODE_U8
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//#define SAMPLE_MODE_S16
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//#define ADC_PRESCALE_16 /* Up to ~60kHz. */
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//#define ADC_PRESCALE_32 /* Up to ~27kHz. */
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#define ADC_PRESCALE_64 /* Up to ~18kHz. */
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#define die(fmt, ...) { cli(); printf("Fatal: " fmt, ##__VA_ARGS__); Serial.flush(); while(1); }
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#define dbg(fmt, ...) printf("Debug: " fmt, ##__VA_ARGS__);
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enum AdcChannel : uint8_t {
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AdcChannel0 = 0,
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AdcChannel1 = 1,
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AdcChannel2 = 2,
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AdcChannel3 = 3,
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AdcChannel4 = 4,
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AdcChannel5 = 5,
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AdcChannel6 = 6,
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AdcChannel7 = 7,
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AdcChannelTemp = 8,
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AdcChannel1V1 = 14,
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AdcChannelGnd = 15,
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};
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const AdcChannel adc_chan = AdcChannel0;
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const uint16_t timer_cmp = 1000; /* 16MHz / 1000 = 16kHz. */
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//const uint16_t timer_cmp = 800; /* 16MHz / 800 = 20kHz. */
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const unsigned long int flush_samples = 64000;
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const int pin_ss = 10;
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File file;
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#if defined(SAMPLE_MODE_U8)
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#define SAMPLE_BUF_SIZE 128
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#define SAMPLE_BUF_TYPE uint8_t
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#elif defined(SAMPLE_MODE_S16)
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#define SAMPLE_BUF_SIZE 64
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#define SAMPLE_BUF_TYPE int16_t
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#endif
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volatile SAMPLE_BUF_TYPE sample_buffer[2][SAMPLE_BUF_SIZE];
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volatile bool which_buffer = 0;
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volatile uint16_t samples_in_buffer[2] = {0, 0};
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volatile unsigned long int samples_hanging = 0;
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volatile unsigned long int samples_written = 0;
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volatile unsigned long int samples_dropped = 0;
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#ifdef DEBUG_RECORDING
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volatile unsigned long int dbg_total = 0;
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volatile unsigned long int dbg_sum = 0;
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volatile unsigned long int dbg_samples = 0;
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volatile int16_t dbg_min = 32767;
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volatile int16_t dbg_max = -32768;
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#endif
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ISR(TIMER1_COMPA_vect) {
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/* Only write to file, if one of the buffers is full (meaning no access conflicts). */
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if (samples_in_buffer[!which_buffer] == SAMPLE_BUF_SIZE) {
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TIMSK1 &= ~_BV(OCIE1A);
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sei();
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const size_t bufsz = sizeof(SAMPLE_BUF_TYPE) * samples_in_buffer[!which_buffer];
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if (file.write((char*)sample_buffer[!which_buffer], bufsz) != bufsz)
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die("Error writing to SD card!\n");
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samples_hanging += samples_in_buffer[!which_buffer];
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samples_in_buffer[!which_buffer] = 0;
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if (samples_hanging >= flush_samples) {
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samples_written += samples_hanging;
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samples_hanging = 0;
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wav_write_header(samples_written);
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file.flush();
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}
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TIMSK1 |= _BV(OCIE1A);
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}
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}
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ISR(TIMER1_COMPB_vect) {
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// Retrieve ADC Value and Write to Buffer
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#if defined(SAMPLE_MODE_U8)
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uint8_t adcval = ADCH;
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#elif defined(SAMPLE_MODE_S16)
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uint8_t l = ADCL; /* Read ADC registers. (Order matters!) */
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uint8_t h = ADCH;
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int16_t adcval = (h << 8) | l;
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adcval -= 0x0200; /* Make integer signed. */
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adcval <<= 6; /* Turn 10-bit integer into 16-bit integer. */
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#endif
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if (samples_in_buffer[which_buffer] >= SAMPLE_BUF_SIZE)
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which_buffer = !which_buffer;
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if (samples_in_buffer[which_buffer] < SAMPLE_BUF_SIZE)
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sample_buffer[which_buffer][samples_in_buffer[which_buffer]++] = adcval;
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else
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samples_dropped++;
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#ifdef DEBUG_RECORDING
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dbg_total++;
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dbg_samples++;
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dbg_sum += adcval;
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if (adcval < dbg_min)
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dbg_min = adcval;
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if (adcval > dbg_max)
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dbg_max = adcval;
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#endif
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}
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void wav_write_header(uint32_t nsamples) {
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unsigned long old_pos = file.position();
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if (!file.seek(0))
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die("Error seeking to position 0!\n");
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const uint16_t channels = 1;
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const uint32_t riff_chunk_size = sizeof(SAMPLE_BUF_TYPE) * nsamples * channels + 4 + 24 + 8;
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const uint32_t fmt_chunk_size = 16;
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const uint16_t fmt_tag = 1; /* 1 = PCM. */
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const uint32_t sample_rate = F_CPU / timer_cmp;
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const uint32_t data_rate = sizeof(SAMPLE_BUF_TYPE) * channels * sample_rate;
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const uint16_t block_align = sizeof(SAMPLE_BUF_TYPE) * channels;
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const uint16_t bits_per_sample = sizeof(SAMPLE_BUF_TYPE) * 8;
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const uint32_t data_size = sizeof(SAMPLE_BUF_TYPE) * nsamples * channels;
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// RIFF
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if(file.write((char*)"RIFF", 4) != 4
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|| file.write((char*)&riff_chunk_size, 4) != 4
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|| file.write((char*)"WAVE", 4) != 4
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// fmt
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|| file.write((char*)"fmt ", 4) != 4
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|| file.write((char*)&fmt_chunk_size, 4) != 4
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|| file.write((char*)&fmt_tag, 2) != 2
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|| file.write((char*)&channels, 2) != 2
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|| file.write((char*)&sample_rate, 4) != 4
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|| file.write((char*)&data_rate, 4) != 4
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|| file.write((char*)&block_align, 2) != 2
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|| file.write((char*)&bits_per_sample, 2) != 2
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// data
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|| file.write((char*)"data", 4) != 4
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|| file.write((char*)&data_size, 4) != 4)
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die("Error writing WAV header to SD card!\n");
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if (old_pos > file.position()) {
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if(!file.seek(old_pos))
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die("Error seeking to position %lu!\n", old_pos);
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}
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}
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void setup() {
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// Serial Setup
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Serial.begin(9600); /* Set baud rate. */
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setup_serial_in_out(); /* Add printf support. */
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// SD Card Setup
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if (!SD.begin(pin_ss))
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die("Error initializing SD card!\n");
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// Determine Filename
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unsigned int filenum = 0;
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char filename[32];
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do {
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filenum++;
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snprintf(filename, 32, "rec_%03u.wav", filenum);
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} while (SD.exists(filename));
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// Open File
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file = SD.open(filename, O_READ | O_WRITE | O_CREAT); /* Seeking doesn't seem to work with FILE_WRITE?! */
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printf("Recording to file '%s'.\n", filename);
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if (!file)
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die("Error opening '%s' for writing!\n", filename);
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wav_write_header(0);
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// ADC Setup
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DIDR0 |= (0xF & adc_chan); /* Disable digital input. */
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ADCSRA = _BV(ADEN) /* Enable ADC. */
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| _BV(ADATE) /* Enable auto-trigger. */
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#if defined(ADC_PRESCALE_64) /* Up to ~18kHz. */
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| _BV(ADPS2) | _BV(ADPS1); /* ADC prescaler division factor: 64. */
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#elif defined(ADC_PRESCALE_32) /* Up to ~27kHz. */
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| _BV(ADPS2) | _BV(ADPS0); /* ADC prescaler division factor: 32. */
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#elif defined(ADC_PRESCALE_16) /* Up to ~60kHz. */
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| _BV(ADPS2); /* ADC prescaler division factor: 16. */
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#endif
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ADCSRB = _BV(ADTS2) | _BV(ADTS0); /* Auto-trigger source select: "Timer/Counter1 Compare Match B". */
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ADMUX = _BV(REFS0) /* Use AREF pin (VCC by default) as reference voltage. */
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#if defined(SAMPLE_MODE_U8)
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| _BV(ADLAR) /* Left adjust ADC output so we only need to read ADCH. */
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#endif
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| (0xF & adc_chan); /* Select our ADC input channel. */
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// Timer Setup
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TCCR1A = _BV(WGM13) | _BV(WGM12) | _BV(WGM11); /* Set timer 1 on A channel to ICR1 fast PWM. (Required to make channel B fire at the correct speed). */
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TCCR1B = _BV(WGM13) | _BV(WGM12) /* Make timer 1 on B channel compare to ICR1 in CTC (Clear Timer on Compare match) mode. */
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| _BV(CS10); /* Set timer prescaler division factor to 1. */
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ICR1 = timer_cmp; /* Set timer compare value: freqency = CPU frequency (16MHz) / timer_cmp. */
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TIMSK1 = _BV(OCIE1A)
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| _BV(OCIE1B); /* Enable "Output Compare B Match Interrupt". */
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}
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void loop() {
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delay(1000);
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#ifdef DEBUG_RECORDING
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dbg("n=%lu\tavg=%lu\tmin=%d\tmax=%d\n", dbg_total, dbg_sum / (dbg_samples ? dbg_samples : 1), dbg_min, dbg_max);
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dbg_sum = 0;
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dbg_samples = 0;
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dbg_min = 32767;
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dbg_max = -32768;
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#endif
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printf("samples: written=%lu, hanging=%lu, dropped=%lu\n", samples_written, samples_hanging, samples_dropped);
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}
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