I’m working on an iOT device integrating a speaker, with programs developed on Particle that stream music using API calls (such as Spotify).
Until know, I was prototyping on a PI 3 using a 32bits DAC hat, an amplifier and the speaker. This is an easy plug&play configuration to make audio works.
But the lack of PWM Pins on the PI needed for other features will probably force me to change. Also the Price of this configuration is expensive.
Do you think I might have other hardware options for prototyping, especially with a Photon or a Redbear duo (cheaper & lots of PWM pins) ?
Or would it be absolutely not relevant, especially because they lack power ?
Thank you very much for your help !
Someone might help on this ? @KyleG maybe?
I suspect it will be hard to get this to work. The STM32 processor is probably not fast enough to read data from the network, decode compression (MP3, AAC, whatever) and output the data by PWM.
And if you add an external audio codec chip to do the audio decompression and an amplifier you’re getting back into the range where it’s not really cheaper than using the Pi.
We build fairly expensive HiFi here and for streaming we buy in a module (converse digital) that comes complete with all the necessary bits to access things like spotify, Quobuz, deezer, BBC etc. While many of these services have APIs anyone can access as soon as you put them in a piece of commercial hardware they start holding their hands out for money. There are a few of these modules around, some are good some apparently are not. Some are accessible, some are surrounded in NDAs, mystery and buzzspeak and seemingly don’t physically exist (Qualcomm). This probably costs a bit more than a Pi and isn’t really available for hobbyists, a distributor could certainly sort you out with a dev board. Depending what you were up to you could possibly add IoT functionality using a Particle device, obviously such products are designed to be controlled over the LAN with an app/DNLA/UPNP.
You can buy what should be perfectly good ClassD amps on eBay based on the TDA chips combined with a DAC that should mean you end up with somethign doing the same job as something like this https://www.justboom.co/product/justboom-amp-hat/
What were you after all the PWM for?
Also to my my mind the Amp Hat @ £60 to Joe Public is a perfectly respectable price for what it is, at least 2 layers of people are getting margin in that price
Thank you for your answers !
@rickkas7 that’s what I have feared, but you are probably right…
@Viscacha, this type of streaming modules seems nice but not exactly what I am looking for because I need to control every streaming source/API etc. But you are right Justboom products are good quality for the PI.
As you suggest, for now I will try to “fake” PWM using programs based on the PI GPIO pins. I needed them to control 2 potentiometer buttons and 2 dimmable LEDS. I think I can manage with this option.
I will let you know if it works, thanks guys