333 lines
11 KiB
C++
333 lines
11 KiB
C++
/*
|
|
*** SD Card Wiring ***
|
|
SD | Nano
|
|
______________________
|
|
D0 (DO) | D12 (MISO)
|
|
VSS | GND
|
|
CLK | D13 (SCK)
|
|
VDD | 5V or 3V3
|
|
CMD (DI) | D11 (MOSI)
|
|
D3 (CS) | D10 (SS)
|
|
|
|
WARNING: SD cards are not designed for 5V; I have been using 5V anyways
|
|
and everything seems fine, but beware that there is a significant risk
|
|
of immediate or premature failure when not using a buffer circuit.
|
|
|
|
SD pin D3 is the chip select pin. It can be set manually in PIN_SS.
|
|
|
|
*** Microphone Wiring (MAX9814 w/ electret microphone) ***
|
|
Mic | Nano
|
|
______________________
|
|
VCC | 5V
|
|
GND | GND
|
|
Out | A0
|
|
|
|
Out defaults to A0 (AdcChannel0), but can be set manually in ADC_CHANNEL.
|
|
*/
|
|
|
|
#include <SD.h>
|
|
#include <SPI.h>
|
|
#include <avr/interrupt.h>
|
|
#include <avr/io.h>
|
|
#include <avr/wdt.h>
|
|
|
|
/************************
|
|
BEGIN USER CONFIGURATION
|
|
************************/
|
|
//#define DEBUG_RECORDING
|
|
//#define SERIAL_OUTPUT
|
|
|
|
#define SAMPLE_MODE_U8
|
|
//#define SAMPLE_MODE_S16
|
|
|
|
//#define ADC_PRESCALE_16 /* Up to ~60kHz. */
|
|
//#define ADC_PRESCALE_32 /* Up to ~27kHz. */
|
|
#define ADC_PRESCALE_64 /* Up to ~18kHz. */
|
|
|
|
#define U8_EXTRA_PRECISION /* (U8 sampling mode only) use 9th ADC reading bit and chop off 1st bit for more precision (sacrificing half of the bandwidth) */
|
|
|
|
#define RECORDING_DELAY_IN_MINUTES 0 /* Wait n minutes before starting to record. */
|
|
#define ADC_CHANNEL AdcChannel0
|
|
#define TIMER_COMPARE 1000 /* 16MHz / 1000 = 16kHz. */
|
|
#define FLUSH_SAMPLES 64000 /* Flush WAV file every n samples. */
|
|
#define PIN_SS 10
|
|
/**********************
|
|
END USER CONFIGURATION
|
|
**********************/
|
|
|
|
#ifdef SERIAL_OUTPUT
|
|
static int serial_putch(char c, FILE *f) {
|
|
(void)f;
|
|
return Serial.write(c) == 1 ? 0 : 1;
|
|
}
|
|
|
|
static int serial_getch(FILE *f) {
|
|
(void)f;
|
|
while(Serial.available() == 0);
|
|
return Serial.read();
|
|
}
|
|
|
|
static FILE serial_in_out;
|
|
|
|
static void setup_serial_in_out() {
|
|
fdev_setup_stream(&serial_in_out, serial_putch, serial_getch, _FDEV_SETUP_RW);
|
|
stdout = stdin = stderr = &serial_in_out;
|
|
}
|
|
|
|
static size_t fstrlen(const __FlashStringHelper *s) {
|
|
PGM_P sp = (PGM_P)s;
|
|
size_t len = 0;
|
|
while (pgm_read_byte(sp++))
|
|
len++;
|
|
return len;
|
|
}
|
|
|
|
static int printf(const __FlashStringHelper *fmt, ...) {
|
|
size_t len = fstrlen(fmt);
|
|
char buf[len + 1];
|
|
buf[len] = 0;
|
|
memcpy_P(buf, fmt, len + 1);
|
|
|
|
va_list args;
|
|
va_start(args, fmt);
|
|
int ret = vprintf(buf, args);
|
|
va_end(args);
|
|
return ret;
|
|
}
|
|
|
|
#define die(fmt, ...) { disable_recording_interrupts(); printf(F("Fatal: ")); printf(fmt, ##__VA_ARGS__); Serial.flush(); while(1); }
|
|
#define dbg(fmt, ...) { printf(F("Debug: ")); printf(fmt, ##__VA_ARGS__); }
|
|
#define print_special(x) Serial.print(x)
|
|
#else
|
|
#define printf(fmt, ...) {}
|
|
#define die(fmt, ...) { disable_recording_interrupts(); while(1); }
|
|
#define dbg(fmt, ...) {}
|
|
#define print_special(x) {}
|
|
#endif
|
|
|
|
#if defined(RECORDING_DELAY_IN_MINUTES) && RECORDING_DELAY_IN_MINUTES != 0
|
|
#include <LowPower.h> /* https://github.com/rocketscream/Low-Power */
|
|
static void low_power_sleep_minutes(unsigned long t) {
|
|
for (unsigned long i = 0; 8ul * i < 60ul * t; i++) {
|
|
/* Power down for 8s. */
|
|
LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static void start_watchdog_with_full_reset() {
|
|
MCUSR &= ~B00001000; /* Clear reset flag. */
|
|
WDTCSR |= B00011000; /* Prepare prescaler change. */
|
|
WDTCSR = B00100001; /* Set watchdog timeout to 8s. */
|
|
// Enable Watchdog Timer
|
|
WDTCSR |= B01000000;
|
|
MCUSR = MCUSR & B11110111;
|
|
}
|
|
|
|
static inline void disable_recording_interrupts() {
|
|
TIMSK1 &= ~(_BV(OCIE1A) | _BV(OCIE1B));
|
|
}
|
|
|
|
enum AdcChannel : uint8_t {
|
|
AdcChannel0 = 0,
|
|
AdcChannel1 = 1,
|
|
AdcChannel2 = 2,
|
|
AdcChannel3 = 3,
|
|
AdcChannel4 = 4,
|
|
AdcChannel5 = 5,
|
|
AdcChannel6 = 6,
|
|
AdcChannel7 = 7,
|
|
AdcChannelTemp = 8,
|
|
AdcChannel1V1 = 14,
|
|
AdcChannelGnd = 15,
|
|
};
|
|
|
|
File file;
|
|
#if defined(SAMPLE_MODE_U8)
|
|
#define SAMPLE_BUF_SIZE 256
|
|
#define SAMPLE_BUF_TYPE uint8_t
|
|
#elif defined(SAMPLE_MODE_S16)
|
|
#define SAMPLE_BUF_SIZE 160
|
|
#define SAMPLE_BUF_TYPE int16_t
|
|
#endif
|
|
volatile SAMPLE_BUF_TYPE sample_buffer[2][SAMPLE_BUF_SIZE];
|
|
volatile bool which_buffer = 0;
|
|
volatile uint16_t samples_in_buffer[2] = {0, 0};
|
|
volatile unsigned long samples_hanging = 0;
|
|
volatile unsigned long samples_written = 0;
|
|
volatile unsigned long samples_dropped = 0;
|
|
#ifdef DEBUG_RECORDING
|
|
volatile unsigned long dbg_total = 0;
|
|
volatile unsigned long dbg_sum = 0;
|
|
volatile unsigned long dbg_samples = 0;
|
|
volatile int16_t dbg_min = 32767;
|
|
volatile int16_t dbg_max = -32768;
|
|
#endif
|
|
|
|
ISR(TIMER1_COMPA_vect) {
|
|
/* Only write to file, if one of the buffers is full (meaning no access conflicts). */
|
|
if (samples_in_buffer[!which_buffer] == SAMPLE_BUF_SIZE) {
|
|
TIMSK1 &= ~_BV(OCIE1A);
|
|
sei();
|
|
const size_t bufsz = sizeof(SAMPLE_BUF_TYPE) * samples_in_buffer[!which_buffer];
|
|
if (file.write((char*)sample_buffer[!which_buffer], bufsz) != bufsz) {
|
|
printf(F("Lost "));
|
|
print_special((float)samples_hanging / (float)(F_CPU / TIMER_COMPARE)); /* Printf doesn't handle floats. */
|
|
printf(F(" seconds of recording.\n"));
|
|
die(F("Error writing to SD card. You can ignore this if you removed the SD card intentionally.\n"));
|
|
}
|
|
samples_hanging += samples_in_buffer[!which_buffer];
|
|
samples_in_buffer[!which_buffer] = 0;
|
|
if (samples_hanging >= FLUSH_SAMPLES) {
|
|
samples_written += samples_hanging;
|
|
samples_hanging = 0;
|
|
wav_write_header(samples_written);
|
|
file.flush();
|
|
}
|
|
TIMSK1 |= _BV(OCIE1A);
|
|
}
|
|
}
|
|
|
|
ISR(TIMER1_COMPB_vect) {
|
|
// Retrieve ADC Value and Write to Buffer
|
|
#if defined(SAMPLE_MODE_U8)
|
|
#ifdef U8_EXTRA_PRECISION
|
|
uint8_t l = ADCL; /* Read ADC registers. (Order matters!) */
|
|
uint8_t h = ADCH;
|
|
uint8_t adcval = (h << 7) | (l >> 1);
|
|
#else
|
|
uint8_t adcval = ADCH;
|
|
#endif
|
|
#elif defined(SAMPLE_MODE_S16)
|
|
uint8_t l = ADCL;
|
|
uint8_t h = ADCH;
|
|
int16_t adcval = (h << 8) | l;
|
|
adcval -= 0x0200; /* Make integer signed. */
|
|
adcval <<= 6; /* Turn 10-bit integer into 16-bit integer. */
|
|
#endif
|
|
if (samples_in_buffer[which_buffer] >= SAMPLE_BUF_SIZE)
|
|
which_buffer = !which_buffer;
|
|
if (samples_in_buffer[which_buffer] < SAMPLE_BUF_SIZE)
|
|
sample_buffer[which_buffer][samples_in_buffer[which_buffer]++] = adcval;
|
|
else
|
|
samples_dropped++;
|
|
#ifdef DEBUG_RECORDING
|
|
dbg_total++;
|
|
dbg_samples++;
|
|
dbg_sum += adcval;
|
|
if (adcval < dbg_min)
|
|
dbg_min = adcval;
|
|
if (adcval > dbg_max)
|
|
dbg_max = adcval;
|
|
#endif
|
|
}
|
|
|
|
static void wav_write_header(uint32_t nsamples) {
|
|
unsigned long old_pos = file.position();
|
|
|
|
if (!file.seek(0))
|
|
die(F("Error seeking to position 0!\n"));
|
|
|
|
const uint16_t channels = 1;
|
|
const uint32_t riff_chunk_size = sizeof(SAMPLE_BUF_TYPE) * nsamples * channels + 4 + 24 + 8;
|
|
const uint32_t fmt_chunk_size = 16;
|
|
const uint16_t fmt_tag = 1; /* 1 = PCM. */
|
|
const uint32_t sample_rate = F_CPU / TIMER_COMPARE;
|
|
const uint32_t data_rate = sizeof(SAMPLE_BUF_TYPE) * channels * sample_rate;
|
|
const uint16_t block_align = sizeof(SAMPLE_BUF_TYPE) * channels;
|
|
const uint16_t bits_per_sample = sizeof(SAMPLE_BUF_TYPE) * 8;
|
|
const uint32_t data_size = sizeof(SAMPLE_BUF_TYPE) * nsamples * channels;
|
|
|
|
// RIFF
|
|
if(file.write((char*)"RIFF", 4) != 4
|
|
|| file.write((char*)&riff_chunk_size, 4) != 4
|
|
|| file.write((char*)"WAVE", 4) != 4
|
|
// fmt
|
|
|| file.write((char*)"fmt ", 4) != 4
|
|
|| file.write((char*)&fmt_chunk_size, 4) != 4
|
|
|| file.write((char*)&fmt_tag, 2) != 2
|
|
|| file.write((char*)&channels, 2) != 2
|
|
|| file.write((char*)&sample_rate, 4) != 4
|
|
|| file.write((char*)&data_rate, 4) != 4
|
|
|| file.write((char*)&block_align, 2) != 2
|
|
|| file.write((char*)&bits_per_sample, 2) != 2
|
|
// data
|
|
|| file.write((char*)"data", 4) != 4
|
|
|| file.write((char*)&data_size, 4) != 4)
|
|
die(F("Error writing WAV header to SD card!\n"));
|
|
|
|
if (old_pos > file.position()) {
|
|
if(!file.seek(old_pos))
|
|
die(F("Error seeking to position %lu!\n"), old_pos);
|
|
}
|
|
}
|
|
|
|
void setup() {
|
|
// Serial Setup
|
|
#ifdef SERIAL_OUTPUT
|
|
Serial.begin(9600); /* Set baud rate. */
|
|
setup_serial_in_out(); /* Add printf support. */
|
|
#endif
|
|
// Delay Triggering
|
|
#if defined(RECORDING_DELAY_IN_MINUTES) && RECORDING_DELAY_IN_MINUTES != 0
|
|
printf(F("Waiting %u minute%s before starting to record...\n"), RECORDING_DELAY_IN_MINUTES, RECORDING_DELAY_IN_MINUTES == 1 ? "" : "s");
|
|
Serial.flush();
|
|
low_power_sleep_minutes(RECORDING_DELAY_IN_MINUTES); /* Draws ~12.5mA instead of ~30mA when using delay(). */
|
|
#endif
|
|
// Start Watchdog (wdt_enable() doesn't fully reset)
|
|
start_watchdog_with_full_reset();
|
|
// SD Card Setup
|
|
if (!SD.begin(PIN_SS))
|
|
die(F("Error initializing SD card!\n"));
|
|
// Determine Filename
|
|
unsigned int filenum = 0;
|
|
char filename[32];
|
|
do {
|
|
filenum++;
|
|
snprintf(filename, 32, "rec_%03u.wav", filenum);
|
|
} while (SD.exists(filename));
|
|
// Open File
|
|
file = SD.open(filename, O_READ | O_WRITE | O_CREAT); /* Seeking doesn't seem to work with FILE_WRITE?! */
|
|
printf(F("Recording to file '%s'.\n"), filename);
|
|
if (!file)
|
|
die(F("Error opening '%s' for writing!\n"), filename);
|
|
wav_write_header(0);
|
|
// ADC Setup
|
|
DIDR0 |= (0xF & ADC_CHANNEL); /* Disable digital input. */
|
|
ADCSRA = _BV(ADEN) /* Enable ADC. */
|
|
| _BV(ADATE) /* Enable auto-trigger. */
|
|
#if defined(ADC_PRESCALE_64) /* Up to ~18kHz. */
|
|
| _BV(ADPS2) | _BV(ADPS1); /* ADC prescaler division factor: 64. */
|
|
#elif defined(ADC_PRESCALE_32) /* Up to ~27kHz. */
|
|
| _BV(ADPS2) | _BV(ADPS0); /* ADC prescaler division factor: 32. */
|
|
#elif defined(ADC_PRESCALE_16) /* Up to ~60kHz. */
|
|
| _BV(ADPS2); /* ADC prescaler division factor: 16. */
|
|
#endif
|
|
ADCSRB = _BV(ADTS2) | _BV(ADTS0); /* Auto-trigger source select: "Timer/Counter1 Compare Match B". */
|
|
ADMUX = _BV(REFS0) /* Use AREF pin (VCC by default) as reference voltage. */
|
|
#if defined(SAMPLE_MODE_U8) && !defined(U8_EXTRA_PRECISION)
|
|
| _BV(ADLAR) /* Left adjust ADC output so we only need to read ADCH. */
|
|
#endif
|
|
| (0xF & ADC_CHANNEL); /* Select our ADC input channel. */
|
|
// Timer Setup
|
|
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). */
|
|
TCCR1B = _BV(WGM13) | _BV(WGM12) /* Make timer 1 on B channel compare to ICR1 in CTC (Clear Timer on Compare match) mode. */
|
|
| _BV(CS10); /* Set timer prescaler division factor to 1. */
|
|
ICR1 = TIMER_COMPARE; /* Set timer compare value: freqency = CPU frequency (16MHz) / TIMER_COMPARE. */
|
|
TIMSK1 = _BV(OCIE1A) /* Use interrupt A for updating the data on the SD card. */
|
|
| _BV(OCIE1B); /* Enable "Output Compare B Match Interrupt". */
|
|
}
|
|
|
|
void loop() {
|
|
delay(1000);
|
|
wdt_reset(); /* Reset watchdog timer. */
|
|
#ifdef DEBUG_RECORDING
|
|
dbg(F("n=%lu\tavg=%lu\tmin=%d\tmax=%d\n"), dbg_total, dbg_sum / (dbg_samples ? dbg_samples : 1), dbg_min, dbg_max);
|
|
dbg_sum = 0;
|
|
dbg_samples = 0;
|
|
dbg_min = 32767;
|
|
dbg_max = -32768;
|
|
#endif
|
|
printf(F("samples: written=%lu, hanging=%lu, dropped=%lu\n"), samples_written, samples_hanging, samples_dropped);
|
|
}
|