diff --git a/examples/Platforms/NRF52/NRF52_SD_Playback_I2S_Auto/NRF52_SD_Playback_I2S_Auto.ino b/examples/Platforms/NRF52/NRF52_SD_Playback_I2S_Auto/NRF52_SD_Playback_I2S_Auto.ino new file mode 100644 index 0000000..37a24fc --- /dev/null +++ b/examples/Platforms/NRF52/NRF52_SD_Playback_I2S_Auto/NRF52_SD_Playback_I2S_Auto.ino @@ -0,0 +1,134 @@ +/* + AutoAnalogAudio streaming via DAC & ADC by TMRh20 + Copyright (C) 2016 TMRh20 - tmrh20@gmail.com, github.com/TMRh20 + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . + + Auto Analog Audio (Automatic DAC, ADC & Timer) library + + Auto Analog Audio Library Information: + http://github.com/TMRh20 + http://tmrh20.blogspot.com + + This example automatically determines the format of WAV files & + attempts to play them. +*/ + +#include +#include +#include + +AutoAnalog aaAudio; +SdFat SD; + +/*********************************************************/ +/* Tested with MAX98357A I2S breakout +/* BCLK connected to Arduino D1 (p0.03) +/* LRCK connected to Arduino D3 (p0.29) +/* DIN connected to Arduino D5 (p0.05) +/* SD connected to Arduino D6 (p1.11) +/*********************************************************/ +float volumeControl = 0.2; +#define BUFFER_SIZE 640 + +void setup() { + + Serial.begin(115200); + + Serial.print("Init SD card..."); + if (!SD.begin(2, 32000000)) { + Serial.println("init failed!"); + return; + } + Serial.println("init ok"); + Serial.println("Analog Audio Begin"); + aaAudio.begin(0, 1, 1); //Setup aaAudio using DAC and I2S + + pinMode(6, OUTPUT); //Connected to SD pin of MAX98357A + digitalWrite(6, HIGH); + + playAudio("brick/brick24.wav"); // 24kHz @ 16-bits is about the maximum when reading from SD card +} + +void loop() { + + loadBuffer(); + + + if (Serial.available()) { + char c = Serial.read(); + if (c == '=') { + volumeControl += 0.1; + } else if (c == '-') { + volumeControl -= 0.1; + volumeControl = max(0.0, volumeControl); + } else if (c == 'p') { + playAudio("brick/brick24.wav"); + } + Serial.println(volumeControl); + } +} + +/*********************************************************/ +/* A simple function to handle playing audio files +/*********************************************************/ + +File myFile; + +void playAudio(char *audioFile) { + + if (myFile) { + myFile.close(); + } + //Open the designated file + myFile = SD.open(audioFile); + + myFile.seek(22); + uint16_t var; + uint32_t var2; + myFile.read(&var, 2); // Get channels (Stereo or Mono) + myFile.read(&var2, 4); // Get Sample Rate + aaAudio.setSampleRate(var2, var - 1); + + myFile.seek(34); + myFile.read(&var, 2); // Get Bits Per Sample + aaAudio.dacBitsPerSample = var; + + myFile.seek(44); //Skip past the WAV header +} + +void loadBuffer() { + + if (myFile.available()) { + + if (aaAudio.dacBitsPerSample == 8) { + myFile.read(aaAudio.dacBuffer, BUFFER_SIZE); // Change this to dacBuffer16 for 16-bit samples + for (uint32_t i = 0; i < BUFFER_SIZE; i++) { + aaAudio.dacBuffer[i] *= volumeControl; + } + aaAudio.feedDAC(0, BUFFER_SIZE); // change this to 3200 for 16-bit samples + } else { + myFile.read(aaAudio.dacBuffer16, BUFFER_SIZE); // Change this to dacBuffer16 for 16-bit samples + for (uint32_t i = 0; i < BUFFER_SIZE / 2; i++) { + aaAudio.dacBuffer16[i] += 0x8000; + aaAudio.dacBuffer16[i] *= volumeControl; + aaAudio.dacBuffer16[i] -= 0x8000; + } + aaAudio.feedDAC(0, BUFFER_SIZE / 2); // change this to 3200 for 16-bit samples + } + + } else { + myFile.seek(44); + } +}