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r4 2022-03-26 16:45:33 +01:00
commit 382d659d4d

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spybug.ino Normal file
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/* Wiring:
SD | Nano
______________________
D0 (DO) | D12 (MISO)
VSS | GND
CLK | D13 (SCK)
VDD | 3V3
CMD (DI) | D11 (MOSI)
D3 (CS) | D10 (SS)
SD pin D3 is the chip select pin (must be set manually in pin_ss).
*/
#include <avr/io.h>
#include <avr/interrupt.h>
#include <SPI.h>
#include <SD.h>
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;
}
//#define DEBUG_RECORDING
#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 die(fmt, ...) { cli(); printf("Fatal: " fmt, ##__VA_ARGS__); Serial.flush(); while(1); }
#define dbg(fmt, ...) printf("Debug: " fmt, ##__VA_ARGS__);
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,
};
const AdcChannel adc_chan = AdcChannel0;
const uint16_t timer_cmp = 1000; /* 16MHz / 1000 = 16kHz. */
//const uint16_t timer_cmp = 800; /* 16MHz / 800 = 20kHz. */
const unsigned long int flush_samples = 64000;
const int pin_ss = 10;
File file;
#if defined(SAMPLE_MODE_U8)
#define SAMPLE_BUF_SIZE 128
#define SAMPLE_BUF_TYPE uint8_t
#elif defined(SAMPLE_MODE_S16)
#define SAMPLE_BUF_SIZE 64
#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 int samples_hanging = 0;
volatile unsigned long int samples_written = 0;
volatile unsigned long int samples_dropped = 0;
#ifdef DEBUG_RECORDING
volatile unsigned long int dbg_total = 0;
volatile unsigned long int dbg_sum = 0;
volatile unsigned long int 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)
die("Error writing to SD card!\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)
uint8_t adcval = ADCH;
#elif defined(SAMPLE_MODE_S16)
uint8_t l = ADCL; /* Read ADC registers. (Order matters!) */
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
}
void wav_write_header(uint32_t nsamples) {
unsigned long old_pos = file.position();
if (!file.seek(0))
die("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_cmp;
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("Error writing WAV header to SD card!\n");
if (old_pos > file.position()) {
if(!file.seek(old_pos))
die("Error seeking to position %lu!\n", old_pos);
}
}
void setup() {
// Serial Setup
Serial.begin(9600); /* Set baud rate. */
setup_serial_in_out(); /* Add printf support. */
// SD Card Setup
if (!SD.begin(pin_ss))
die("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("Recording to file '%s'.\n", filename);
if (!file)
die("Error opening '%s' for writing!\n", filename);
wav_write_header(0);
// ADC Setup
DIDR0 |= (0xF & adc_chan); /* 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)
| _BV(ADLAR) /* Left adjust ADC output so we only need to read ADCH. */
#endif
| (0xF & adc_chan); /* 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_cmp; /* Set timer compare value: freqency = CPU frequency (16MHz) / timer_cmp. */
TIMSK1 = _BV(OCIE1A)
| _BV(OCIE1B); /* Enable "Output Compare B Match Interrupt". */
}
void loop() {
delay(1000);
#ifdef DEBUG_RECORDING
dbg("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("samples: written=%lu, hanging=%lu, dropped=%lu\n", samples_written, samples_hanging, samples_dropped);
}