greiman
commented
4 years ago SdFat uses two 512 byte cache buffers. One for FAT entries and one for file data. If you open multiple files, you will have problems since these caches will be invalidated often.
SdFat evolved from a 2008 library for an Arduino Diecimila with a ATmega168, 1 KB SRAM, and 16 KB flash and a single 512 byte sector cache.
It would be possible to extend SdFat for provide cache for each file but I have lost interest in developing SdFat.
SD cards are not intended to be multi stream devices without huge buffers and file read-ahead.
Teensy 4.0 is a nice board but is lacks a decent multi-tasking OS with an integrated file system that can cope with multiple data streams.
alexrjohnston
PaulStoffregen
Hello! first off thanks for the great lib. its amazing how many projects must be using SDfat now : )
I am trying to rid my system of clicks and pops when loading multiple WAVs on Teensy 4.0, several people have mentioned the issues with SD.h so I am trying sdfat on T4. SdFormatter, SdInfo and TeensySdioDemo are all working well! I can even get one wav playing using my own code and its seems the dropouts when a single wav is triggered repeatedly are much improved. Sadly when I try and trigger 4 wavs at the same time, although they play I loose control of the system at the serial window until they have finished playing. If I trigger two wavs at the same time, I can retrigger a couple of times and then I loose control. I also have the cash register sound that I can trigger as it is handy for debug.
Here is the code... (super lean to keep it simple)
`#define USESdFat // uncomment for SdFat.h, comment for SD.h lib.
include "SdFat.h"
SdFat sd;
include
include
include
// GUItool: begin automatically generated code AudioPlayMemory sound0; //xy=257,200 AudioPlaySdWav playSdWav2; //xy=296,375 AudioPlaySdWav playSdWav3; //xy=313,439 AudioPlaySdWav playSdWav1; //xy=324,292 AudioPlaySdWav playSdWav4; //xy=345,516 AudioMixer4 mixer1; //xy=802,203 AudioMixer4 mixer2; //xy=851,322 AudioOutputI2S i2s1; //xy=1069,248 AudioConnection patchCord1(sound0, 0, mixer1, 1); AudioConnection patchCord2(sound0, 0, mixer2, 2); AudioConnection patchCord3(playSdWav1, 0, mixer1, 0); AudioConnection patchCord4(playSdWav1, 1, mixer2, 1); AudioConnection patchCord5(mixer1, 0, i2s1, 0); AudioConnection patchCord6(mixer2, 0, i2s1, 1); // GUItool: end automatically generated code
// Use these with the Teensy Audio Shield //#define SDCARD_CS_PIN 10 //#define SDCARD_MOSI_PIN 7 //#define SDCARD_SCK_PIN 14
// SDCARD_SS_PIN is defined for the built-in SD on some boards.
ifndef SDCARD_SS_PIN
const uint8_t SD_CS_PIN = SS;
else // SDCARD_SS_PIN
// Assume built-in SD is used. const uint8_t SD_CS_PIN = SDCARD_SS_PIN;
endif // SDCARD_SS_PIN
// Use these for the SD+Wiz820 or other adaptors //#define SDCARD_CS_PIN 4 //#define SDCARD_MOSI_PIN 11 //#define SDCARD_SCK_PIN 13 int inByte = 0; byte newDATAin = 1;
include "AudioSampleCashregister.h" // http://www.freesound.org/people/kiddpark/sounds/201159/
void setup() { Serial.begin(115200);
// Audio connections require memory to work. For more // detailed information, see the MemoryAndCpuUsage example AudioMemory(100);
//SPI.setMOSI(SDCARD_MOSI_PIN); ///SPI.setSCK(SDCARD_SCK_PIN); if (!sd.begin(SdioConfig(FIFO_SDIO))) { // stop here, but print a message repetitively while (1) { Serial.println("Unable to access the SD card"); delay(500); } }
}
void loop() {
switch (Serial.read()) {
case 's': { Serial.println("s"); // envelope1.noteOff(); // envelope2.noteOff();tttttttttttt playSdWav1.stop(); playSdWav2.stop(); playSdWav3.stop(); playSdWav4.stop(); //playSdWav5.stop(); //playSdWav6.stop(); //playSdWav7.stop(); //playSdWav8.stop(); sound0.play(AudioSampleCashregister);
} break;
case 't': {
sound0.stop();
playSdWav1.play("10BAB1.WAV");
playSdWav2.play("10BAB2.WAV");
playSdWav3.play("10BAB3.WAV"); playSdWav4.play("10BAB4.WAV");
} break;
case 'y': {
sound0.stop();
playSdWav1.play("10BAB2.WAV");
delay(5);
//playSdWav2.play("10BAB2.WAV");
//playSdWav3.play("10BAB3.WAV"); //playSdWav4.play("10BAB4.WAV");
} break;
} }`
Here is the audio used in the above example: http://donjohnstonmusic.co.uk/tr/sinewavs.zip
I am aware three of the wav players are not connected to any outputs, they still play and cause the issue and its the same when they are connected. is there something in the SDfat settings I can tweak to prevent this hang?
all help very gratefully received, I am properly stuck