/* BasicCompressor_Float Created: Chip Audette, Dec 2016 - Jan 2017 Purpose: Process audio by applying a single-band compressor Demonstrates audio processing using floating point data type. Uses Teensy Audio Adapter. Assumes microphones (or whatever) are attached to the LINE IN (stereo) MIT License. use at your own risk. */ //These are the includes from the Teensy Audio Library #include //Teensy Audio Librarya #include #include #include #include #include //for AudioConvert_I16toF32, AudioConvert_F32toI16, and AudioEffectGain_F32 //create audio library objects for handling the audio AudioControlSGTL5000_Extended sgtl5000; //controller for the Teensy Audio Board AudioInputI2S i2s_in; //Digital audio *from* the Teensy Audio Board ADC. Sends Int16. Stereo. AudioOutputI2S i2s_out; //Digital audio *to* the Teensy Audio Board DAC. Expects Int16. Stereo AudioConvert_I16toF32 int2Float1, int2Float2; //Converts Int16 to Float. See class in AudioStream_F32.h AudioConvert_F32toI16 float2Int1, float2Int2; //Converts Float to Int16. See class in AudioStream_F32.h AudioEffectCompressor_F32 comp1, comp2; //Make all of the audio connections, with the option of USB audio in and out //note that you ALWAYS have to have an I2S connection (either in or out) to have a clock //that drives the system. #define DO_USB 0 //set to 1 to enable USB audio. Be sure to go under the "Tools" menu and do "USB Type" -> "Audio" #if DO_USB AudioInputUSB usb_in; AudioConnection patchCord1(usb_in, 0, int2Float1, 0); AudioConnection patchCord2(usb_in, 1, int2Float2, 0); #else AudioConnection patchCord1(i2s_in, 0, int2Float1, 0); //connect the Left input to the Left Int->Float converter AudioConnection patchCord2(i2s_in, 1, int2Float2, 0); //connect the Right input to the Right Int->Float converter #endif AudioConnection_F32 patchCord10(int2Float1, 0, comp1, 0); //Left. makes Float connections between objects AudioConnection_F32 patchCord11(int2Float2, 0, comp2, 0); //Right. makes Float connections between objects AudioConnection_F32 patchCord12(comp1, 0, float2Int1, 0); //Left. makes Float connections between objects AudioConnection_F32 patchCord13(comp2, 0, float2Int2, 0); //Right. makes Float connections between objects AudioConnection patchCord20(float2Int1, 0, i2s_out, 0); //connect the Left float processor to the Left output AudioConnection patchCord21(float2Int2, 0, i2s_out, 1); //connect the Right float processor to the Right output #if DO_USB AudioOutputUSB usb_out; AudioConnection patchCord30(float2Int1, 0, usb_out, 0); //connect the Left float processor to the Left output AudioConnection patchCord31(float2Int2, 0, usb_out, 1); //connect the Right float processor to the Right output #endif // which input on the audio shield will be used? const int myInput = AUDIO_INPUT_LINEIN; //const int myInput = AUDIO_INPUT_MIC; //I have a potentiometer on the Teensy Audio Board #define POT_PIN A1 //potentiometer is tied to this pin //define a function to setup the Teensy Audio Board how I like it void setupMyAudioBoard(void) { sgtl5000.enable(); //start the audio board sgtl5000.inputSelect(myInput); //choose line-in or mic-in sgtl5000.volume(0.8); //volume can be 0.0 to 1.0. 0.5 seems to be the usual default. sgtl5000.lineInLevel(10, 10); //level can be 0 to 15. 5 is the Teensy Audio Library's default sgtl5000.adcHighPassFilterDisable(); //reduces noise. https://forum.pjrc.com/threads/27215-24-bit-audio-boards?p=78831&viewfull=1#post78831 sgtl5000.micBiasEnable(3.0); //enable the mic bias voltage...only in AudioControlSGTL5000_Extended } //define a function to configure the left and right compressors void setupMyCompressors(boolean use_HP_filter, float knee_dBFS, float comp_ratio, float attack_sec, float release_sec) { comp1.enableHPFilter(use_HP_filter); comp2.enableHPFilter(use_HP_filter); comp1.setThresh_dBFS(knee_dBFS); comp2.setThresh_dBFS(knee_dBFS); comp1.setCompressionRatio(comp_ratio); comp2.setCompressionRatio(comp_ratio); float fs_Hz = AUDIO_SAMPLE_RATE; comp1.setAttack_sec(attack_sec, fs_Hz); comp2.setAttack_sec(attack_sec, fs_Hz); comp1.setRelease_sec(release_sec, fs_Hz); comp2.setRelease_sec(release_sec, fs_Hz); } // define the overall setup() function, the function that is called once when the device is booting void setup() { Serial.begin(115200); //open the USB serial link to enable debugging messages delay(500); //give the computer's USB serial system a moment to catch up. Serial.println("Teensy Hearing Aid: BasicCompressor_Float..."); //identify myself over the USB serial // Audio connections require memory, and the record queue uses this memory to buffer incoming audio. AudioMemory(14); //allocate Int16 audio data blocks AudioMemory_F32(16); //allocate Float32 audio data blocks // Enable the audio shield, select input, and enable output setupMyAudioBoard(); //choose the compressor parameters...note that preGain is set by the potentiometer in the main loop() boolean use_HP_filter = true; //enable the software HP filter to get rid of DC? float knee_dBFS, comp_ratio, attack_sec, release_sec; if (false) { Serial.println("Configuring Compressor for fast response for use as a limitter."); knee_dBFS = -15.0f; comp_ratio = 5.0f; attack_sec = 0.005f; release_sec = 0.200f; } else { Serial.println("Configuring Compressor for slow response more like an automatic volume control."); knee_dBFS = -50.0; comp_ratio = 5.0; attack_sec = 1.0; release_sec = 2.0; } //configure the left and right compressors with the desired settings setupMyCompressors(use_HP_filter, knee_dBFS, comp_ratio, attack_sec, release_sec); // setup any other other features pinMode(POT_PIN, INPUT); //set the potentiometer's input pin as an INPUT } //end setup() // define the loop() function, the function that is repeated over and over for the life of the device unsigned long updatePeriod_millis = 100; //how many milliseconds between updating gain reading? unsigned long lastUpdate_millis = 0; unsigned long curTime_millis = 0; int prev_gain_dB = 0; unsigned long lastMemUpdate_millis = 0; void loop() { //choose to sleep ("wait for interrupt") instead of spinning our wheels doing nothing but consuming power asm(" WFI"); //ARM-specific. Will wake on next interrupt. The audio library issues tons of interrupts, so we wake up often. //has enough time passed to try updating the GUI? curTime_millis = millis(); //what time is it right now if (curTime_millis < lastUpdate_millis) lastUpdate_millis = 0; //handle wrap-around of the clock if ((curTime_millis - lastUpdate_millis) > updatePeriod_millis) { //is it time to update the user interface? //read potentiometer float32_t val = float(analogRead(POT_PIN)) / 1024.0f; //0.0 to 1.0 val = 0.1 * (float)((int)(10.0 * val + 0.5)); //quantize so that it doesn't chatter //compute desired digital gain const float min_gain_dB = -20.0, max_gain_dB = 40.0; //set desired gain range float gain_dB = min_gain_dB + (max_gain_dB - min_gain_dB) * val; //computed desired gain value in dB //if the gain is different than before, set the new gain value if (abs(gain_dB - prev_gain_dB) > 1.0) { //is it different than before prev_gain_dB = gain_dB; //we will use this value the next time around //gain_dB = 0.0; //force to 0 dB for debugging comp1.setPreGain_dB(gain_dB); //set the gain of the Left-channel gain processor comp2.setPreGain_dB(gain_dB); //set the gain of the Right-channel gain processor Serial.print("Setting Digital Pre-Gain dB = "); Serial.println(gain_dB); //print text to Serial port for debugging } lastUpdate_millis = curTime_millis; //we will use this value the next time around. } // end if //print status information to the Serial port if ((curTime_millis - lastMemUpdate_millis) > 2000) { // print a summary of the current & maximum usage //printCompressorState(&Serial); printCPUandMemoryUsage(&Serial); lastMemUpdate_millis = curTime_millis; //we will use this value the next time around. } } //end loop(); void printCompressorState(Stream *s) { s->print("Current Compressor: Pre-Gain (dB) = "); s->print(comp1.getPreGain_dB()); s->print(", Level (dBFS) = "); s->print(comp1.getCurrentLevel_dBFS()); s->print(", "); s->print(comp2.getCurrentLevel_dBFS()); s->print(", Dynamic Gain L/R (dB) = "); s->print(comp1.getCurrentGain_dB()); s->print(", "); s->print(comp2.getCurrentGain_dB()); s->println(); }; void printCPUandMemoryUsage(Stream *s) { s->print("Usage/Max: "); s->print("comp1 CPU = "); s->print(comp1.processorUsage()); s->print("/"); s->print(comp1.processorUsageMax()); s->print(", "); s->print("all CPU = " ); s->print(AudioProcessorUsage()); s->print("/"); s->print(AudioProcessorUsageMax()); s->print(", "); s->print("Int16 Mem = "); s->print(AudioMemoryUsage()); s->print("/"); s->print(AudioMemoryUsageMax()); s->print(", "); s->print("Float Mem = "); s->print(AudioMemoryUsage_F32()); s->print("/"); s->print(AudioMemoryUsageMax_F32()); s->print(", "); s->println(); };