Hello all,
I've been working on a modular synthesizer/sampler project meant to be an addition to the Eurorack synth with a few friends. We were able to get our design working on an Arduino paired with a Raspberry Pi. The basic concept of our design is the module has 4 separate channels which will allow the user to select a channel, assign a .wav file from a microSD card and manipulate the file using a Gate button, Level potentiometer and Pitch potentiometer. Each channel will also have control voltage inputs for each gate, level and pitch.
We decided to pursue the design with the Teensy 3.2 with two Audio Shields to provide outputs to each channel. Our proof of concept design had the audio samples in program memory which is not how we want it to work. We want to allow the user to be able to change the audio samples on the fly with a microSD card.
Our challenges have been utilizing the I2S from the audio shield to ensure CD quality 44.1KHz audio output with an external SD card reader rather than using the SD reader on the audio shield. This is only for ease of use since the SD reader needs to be out at the face of the module while the audio shields are mounted on the teensy with the bulk of the electrical components behind the scene. How viable is this option? Can we use the sgtl5000 codec on the audio shield without using the SD reader while using another external SD reader?
The other question we had was concerning the DSP with the pitch and level manipulation. It also ties in with the previous question, is it possible to use an external SD reader to read in the .wav file into the teensy, manipulate the file and then send it back out through the audio shield without using the built-in SD reader? As of yet we are unable to utilize another SD reader while accessing the audio shield. On a side note, the audio library has been a good source for audio manipulation examples and we will also be adding a BLE module to allow the user to control the channels via a mobile app.
Any feedback would be great!
I'm happy to add any additional information that would be helpful...
I've been working on a modular synthesizer/sampler project meant to be an addition to the Eurorack synth with a few friends. We were able to get our design working on an Arduino paired with a Raspberry Pi. The basic concept of our design is the module has 4 separate channels which will allow the user to select a channel, assign a .wav file from a microSD card and manipulate the file using a Gate button, Level potentiometer and Pitch potentiometer. Each channel will also have control voltage inputs for each gate, level and pitch.
We decided to pursue the design with the Teensy 3.2 with two Audio Shields to provide outputs to each channel. Our proof of concept design had the audio samples in program memory which is not how we want it to work. We want to allow the user to be able to change the audio samples on the fly with a microSD card.
Our challenges have been utilizing the I2S from the audio shield to ensure CD quality 44.1KHz audio output with an external SD card reader rather than using the SD reader on the audio shield. This is only for ease of use since the SD reader needs to be out at the face of the module while the audio shields are mounted on the teensy with the bulk of the electrical components behind the scene. How viable is this option? Can we use the sgtl5000 codec on the audio shield without using the SD reader while using another external SD reader?
The other question we had was concerning the DSP with the pitch and level manipulation. It also ties in with the previous question, is it possible to use an external SD reader to read in the .wav file into the teensy, manipulate the file and then send it back out through the audio shield without using the built-in SD reader? As of yet we are unable to utilize another SD reader while accessing the audio shield. On a side note, the audio library has been a good source for audio manipulation examples and we will also be adding a BLE module to allow the user to control the channels via a mobile app.
Any feedback would be great!
I'm happy to add any additional information that would be helpful...