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Dadamachines Doppler: FPGA open music hardware
- camtarn 8y agoThe fact that it doesn't have an audio output on board by default seems like a really odd omission.
- teilo 8y agoCome again? >2 DAC pins, 10 ADC pins Pins 35 and 39, 2 channels of audio out.
- wallacoloo 8y agoI expect GP meant a 3.5mm audio jack (or similar).
- teilo 8y agoI would be rather annoyed if a project board like this had a hard-wired audio jack.
- camtarn 8y agoYes, I did. I work with industrial controllers with analog outs on a daily basis, but when I wanted to build an audio board I had to do a bunch of research to find out what voltage range I needed to output, and what current I'd need to be able to source/sink. An audio jack is a hardware API contract, basically: plug a wire in here and you will get audio out of it. I don't understand why people would go so far as to be annoyed by the presence of a jack. Are you annoyed by the LED present on most project boards, if you're planning to seal up the board in an enclosure that means you'll never see it? To be fair it would add to the BOM and probably impose additional limits on the board design (large footprint, through hole pins) but I'd argue that the beginner accessibility, and the classification of this board as for audio rather than just another assorted MCU/FPGA board, would be worth it. Of course, the board designers seem to have felt otherwise.
- bayesian_horse 8y agoWhat kind of audio output exactly? How many? A hardwired headphone jack (of which there are various type) would take up space and be useless to many users. Microcontroller-based audio projects often use i2s for audio. Some don't output anything and just listen.
- wallacoloo 8y agoThis is cool, but I question that the addition of a FPGA will really make that much of a difference to make it stand out against the other products on the market that can do realtime DSP, except maybe for battery-operated devices (where maybe the FPGA can be more power-efficient than a general-purpose CPU?) I would have expected the raspberry pi 3 to meet most needs for this market. Quad cores clocked at > 1GHz, USB ports for connecting a controller, analog audio out (or SPI/I2C to a better DAC if you're not happy with the quality), and even HDMI if you want to drive a display, or MIPI for embedded displays. Is it not easy to drive headless, and that's why developers need a different device for this? Or does the FPGA really unlock that much extra possibilities beyond what a quad-core, 1.2 GHz ARM SoC w/ a neon fpu can achieve? Or is there a demand for lower-power devices than the rpi for audio processing? Or am I missing something else entirely? A month back I took a raspberry pi 3 B+, wired a midi keyboard to it, and then launched an open source virtual synth, Helm. I was extremely disappointed by the perf: it was actually unplayable. So clearly there's still a lot that can be done in this domain, and there's probably a reason why already-commodified hardware like the rpi doesn't cut it.
- throwaway98109 8y agoCheck out the hype on the Waldorf Kyra (in prototype this was know as the Valkyrie). The Novation peak is another recent FPGA based device. Take a look at https://novationmusic.com/peak-explained https://novationmusic.com/peak-explained for a bit more of an explanation why FPGA is necessary.
- brandonmenc 8y agoAs someone who is pretty hyped up for the Kyra, this stuff is really just hype. Hype, in the sense that it's anything more than a way to hit a higher level of performance at a smaller budget of dollars and/or watts. Which, is a fine goal. But you can have a gazillion more oscillators and way better resolution with a desktop-class processor. None of these new FPGA synths will sound better than Omnisphere - but they will sound way better than the previous generation of hardware synths. There's kind of a backlash against laptops in music right now - ex: modular and the DAW-less trend - so tons of people want hardware, and plenty of them are yelling "FPGA! FPGA!" like it makes a qualitative difference. Seriously, people on synth message boards are like, "what would this sound like if we did it with FPGA?" I admit that sometimes there is something intangibly great about using hardware versus a laptop - but it's mostly about the interface, not the sound engine.
- teilo 8y agoThe specs for this specific Cortex-M4 incarnation: https://www.microchip.com/wwwproducts/en/ATSAMD51G19A https://www.microchip.com/wwwproducts/en/ATSAMD51G19A The DAC is only 12-bit.
- sbr464 8y agoDidn’t see it mentioned, but bela.io is also a good hardware platform that focuses on low latency. Definitely recommend it.
- postalrat 8y agoAnyone know an affordable microcontroller with a few good dac channels?
- inamberclad 8y agoAn STM32 usually has a few DAC channels, but they often only have 8 or so bits. No idea how fast they are either.
- duskwuff 8y agoThe STM32F4 Discovery board -- among others from ST -- has a decent audio DAC on board. https://www.st.com/en/evaluation-tools/stm32f4discovery.html https://www.st.com/en/evaluation-tools/stm32f4discovery.html
- djmips 8y agoCheck here for a Teensy that will fit your bill. https://www.pjrc.com/teensy/td_libs_Audio.html https://www.pjrc.com/teensy/td_libs_Audio.html
- matchagaucho 8y agoDoes "6 DSP Cores" imply only 6-note polyphony if developing tone generators?
- jerrysievert 8y agono. does having one cpu mean 1-note polyphony when using a laptop to generate tones? you can always mix in software.
- matchagaucho 8y agowell... you never know with these hobby DSPs. Once bitten, twice shy.
- jerrysievert 8y agowell, oscillators are pretty darned lightweight ...
- analog31 8y agoAsk HN: For someone who has done a lot of microcontroller development, but never worked with FPGA's, does this look like a good platform for me to get my feet wet? I'm not sure I need FPGA for anything, but it would be interesting to at least learn the basics.
- Crisco 8y agoIf you're interested in a general purpose FPGA I really like the Alchitry boards[1]. They're pretty straightforward and they have an IDE that simplifies the whole FPGA development process significantly. It runs on top of the FPGA's manufacturer's toolchain so when you feel like you need to move on to more complicated projects you can transition to tools like Vivado. [1] https://alchitry.com/ https://alchitry.com/
- lnsru 8y agoIf you are not sure, you need it, you don’t. Development in low level languages is different paradigm than microcontroller. You can download Xilinx IDE and just simulate some code, that would be enough to know if you want to continue. Digilent is a good provider of hardware: https://store.digilentinc.com/fpga-development-boards-kits-from-digilent/ https://store.digilentinc.com/fpga-development-boards-kits-f... If you like Intel (Altera), grab some board from Terasic.com. The 2 are popular and there’s every possible question asked or described in their blogs. There might be cheaper boards or some non-vendor IDEs, but good support and available information is crucial in your learning phase.
- bayesian_horse 8y agoAt the moment if I were to start with FPGAs I would probably get an TinyFPGA. It has an open source toolchain, and at the price and form factor, it could fit into a lot of projects, even as a slightly expensive customized port-expander. But alas so many things out there to learn and dive into...
- klodolph 8y agoThe engineering challenges here have already been solved with DACs, and FPGAs really bring nothing new to the table. Anything you want to do with audio signal processing is going to involve a lot of multiplication and table lookups. Sure, you can do that with an FPGA, but what you’ve basically got are pieces of DSP stuck in your FPGA that you can wire together with Verilog instead of C. Not exactly something to write home about, since it’s not like you look at your off the shelf DSPs these days and say, “Gosh, these definitely have enough computational power for my needs but I really wish that they were more expensive and more difficult to program.” The problem is that for most synthesizers and music applications, any problem you have is simply not going to require that much computational power by today’s standards. A good way to make digital music toys is to put all your signal processing on a DSP, and then run your UI and random other code on a standard microcontroller. Microcontrollers are cheap, and this way your real-time DSP code isn’t fighting for memory or time slices with anything else. Some people are asking whether you can just use a Raspberry Pi. I’m sure the hardware is capable of cool things with audio, but I’m not sure that you guys would enjoy wrangling Linux into giving you reliable real-time performance.
- bravura 8y agoSome people are asking whether you can just use a Raspberry Pi Can you point us to what hardware (DSPs or DACs) we should use instead? Can I use them as digital synths? Can I use them for digital FX? If I want to make a digital synth with lower latency than a RPi, what hardware should I use that won't be as hard as an FPGA to program?
- klodolph 8y agoThe comment was mostly aimed at the poor state of audio on Linux. I think it’s important to understand what your goals are when you’re doing this. Are you building something? Will it be mass-manufactured? Does it need to be reliable? Does it need to be low-latency? If you’re building something one-shot or playing around, RPi is great it’s just that real-time audio on Linux is a pain. If you want to play with real-time, low-latency effects I would get a Mac or Windows PC and hook it up to a $100 USB audio interface. If you want to mass manufacture a box that makes noise, at that point it starts to make more sense to research DSPs. They often have weird architectures and the toolchains might not be great. But I suspect that more and more audio stuff is moving to general purpose CPUs and microcontrollers.
- amelius 8y agoTo have an impression of the parallel signal processing power of this board, how many 16 bit multipliers fit on the FPGA?
- bayesian_horse 8y agoCan this do recording, too? I'm wondering how to record and process rodent vocalizations in ultrasound (around 20khz) using the cheapest way possible, akin to the "Deep Squeak" project. There are some interesting applications in lab animal welfare, psychology and even training for land mine or TBC detection. High frequency measurement microphones are very expensive. If there was a way to churn a high sampling rate ADC through an FFT inside an FPGA, that would help a lot and it may be simpler or cheaper than for more sophisticated measurements. But beyond basic things like Nyquist frequency I don't really know what I'd need in a microphone and the analog/digital backend...