small dsp board ?

[phil123456]

Hi,
I am actually using puredata but I want to do some embedded dsp and I cant find any simple dsp board I found this, but it's more an fpga than a dsp

https://tinyfpga.com/

back in the day, I had found many small DSP boards, so I been digging google, but now it seems the smallest one are at least the size of a palm

does anyone know any small dsp board ?

regards

[edit : just found tinsy, so far the best one for my needs
small , easy to use, arduino like programming, it also has a nice visual code editor...so far the best]

[Blackaddr]

Teensy 3.6 is a great platform for DIY digital pedals, especially if you take some time to learn the Keil DSP library. The Teensy Audio library makes things SOOOO much easier as well.

I've built a Teensy audio shield specifically for guitar use. I have another batch of boards arriving this week and should have them available on Tindie again within 2 weeks.

https://www.tindie.com/products/Blackaddr/arduino-teensy-guitar-audio-shield/?pt=ac_prod_search

[phil123456]

yeah, it's amazing, just ordered a tinsy 3.6

what does tindie do exactly ? is it needed to interface audio somehow ?

[Blackaddr]

"Tindie" is actually just a website to help makers sell their product.

TGA Pro (Teensy Guitar Audio Pro) is a board I designed to allow easy interfacing of a guitar to the Teensy microcontroller board.

Attaching a guitar safely and so it sounds good actually requires a lot of extra stuff:
1) a high quality audio codec with ADC/DACs designed specifically for audio signal levels and sampling rates. The Teensy built-in ADC/DACs are not really suitable for audio.
2) a preamp with suitable high impedance (500K to 1 Mohm)
3) something capable of either boosting the guitar when it is much less than 1 volt (e.g. single coil pickups)
4) something capable of attenuating the signal when it is greater than 1V (e.g. active pickups, output from a 9V guitar pedal, etc.)
5) something to generate clean analog voltage supplies at various voltages
6) something to protect the electronics from damage when too hot a signal is applied. E.g. If the signal is > than the codec max voltage on the codec (usually 3.3V) we want the audio to clip, but not fry anything.

The TGA pro is designed to take care of all these things for you in one design. It has a 9V guitar preamp, capable of providing up to 12 dB of gain, and the audio CODEC can provide an additional 12db of gain or 34dB of attenuation if needed.

[audioartillery]

I'll second Blackaddr's teensy based solution.  I've got a thread here where I'm building a big pedal around it.

The Blackaddr TGA isn't ideal for building guitar pedals (it's not easy to integrate a lot of control inputs, and the whole thing is pretty bulky) but it's easy to use and of any of the Arduino-type solutions I think it's the only one that was designed correctly from an audio point of view.  It's also inexpensive.  The support has been great too.

The only other option I've found is Mark Seel's FlexFX system which I think is sort of heading towards a kickstarter soon:

https://www.kickstarter.com/projects/632112529/68367638?ref=499075&token=26791363

It's built around an interesting many-core processor which unfortunately means an interesting toolchain.  I think for very processing intense effects this approach has an advantage over ARM-based solutions like the Teensy... but I haven't maxed the Teensy out yet.

[markseel]

This campaign is waiting for a video review to finish.
The pedal is based on the FlexFX module.
Here's some more photos: https://www.instagram.com/3degreesaudio/?hl=en

[Blackaddr]

The Blackaddr TGA isn't ideal for building guitar pedals (it's not easy to integrate a lot of control inputs, and the whole thing is pretty bulky) but it's easy to use and of any of the Arduino-type solutions I think it's the only one that was designed correctly from an audio point of view.  It's also inexpensive.  The support has been great too.

Based on feedback from builders like audioartillery, the "Model B" revision of the TGA Pro just launched a few days ago. It has specific improvements to make fitting it into guitar pedal enclosures easier.
- The Teensy socket has been moved to the same side as the audio jacks, making the total height of the board about 7/8".
- you can request the MIDI connectors not be installed if you do not need them, this frees up quite a bit of volume, particularly if you're trying to make room in the case for the bottom of the STOMP switch.
- analog capable pins (for pots) are now available on headers. I now offer a prototyping Expansion Control Board that plugs directly into the TGA Pro. This gives you a working hardware solution out of the box for adding 3 knobs, 2 switches and 2 LEDs. You can develop with this expansion board, then wire in your own custom controls in your enclosure later.

[guitarrasacusticas2000]

Blackaddr, I downloaded the manual from your website, by the way, very interesting, keep it up! 

[Hamuro]

Hi, I have developed digital multi-effect platform using STM32F103 blue-pll board (72MHz ARM Cortex M3, 20kB RAM), which is very cheap. It is designed for electric guitar but actually it can be used for general digital processing blackbox. The input conversion is 14-bit and the output conversion is 16-bit, all in mono. The sampling frequency is 44100 Hz, there is about 1450 CPU clock is available for processing the sound sample between 1/44100 second period sampling, the remaining CPU clocks is used by the core's process (acquisition, preprocessing, user interface, etc).
Check out this platform at https://www.deepstomp.com/