SparkFun Forums

[chromatech]

Hello,

I had an idea of using nRF2401 to send audio across to another station. Does anyone think if this is even possible?

I know that nRF2401 doesn't have retransmission, therefore the quality of the audio might be bad (unless I would write re-transmit protocol), but just to play around with it I wonder if its possible.

My idea is write a java app to take the audio file, play it and while playing it, send it to an MCU which would send it to nRF2401 which would send it to another MCU which would send it to the PC which would play the samples.

From my tests I get about 50kbps transmission with nRF2401 (anybody get any better?), therefore radio quality audio maybe could be sent.

any ideas about this?

[wheeler]

I wouldn't worry about retransmission if you're streaming (I assume you're streaming). Lost is lost unless you enjoy the whole buffering experience and the delay it introduces.

50kbps sustained should be enough to get some low-quality music streamed, but if you're planning on replaying that music for listening pleasure (it sounds like you are) I would look at the nrf24z1 that is designed for that purpose. To get an idea of what you'll hear at 50k, rip some mp3s at 40kbps and then play them back. And probably add some static. If that's the sound you're going for then it could work.

[chromatech]

i'm mostly going for experimentation.

the problem for me would be to actually get the audio and send it bit samples of max 4 bytes each.
i have no idea about how to sample audio or anythign like that in C++.

but it could be an interesting experiment to see if its possible to do.

thanks for the reply

[RonnyM]

I have seen a number of examples of one bit streaming audio using pics. Converting the sampled audio into a serial stream through either an ADC or more sophisticated CODEC is the choice you have to make. Look at the CC2500 developer's board "DK04"? It has a microphone amp going into the on board processor, and a low pass filter/ headphone amp for an output. The only real difference between the CC2500 and the Nordic part is that the 2500 has a larger FIFO buffer and slightly more versitility in setting up some of the registers. They've even got some C based examples of an RF link and loopback audio project. It should help quite alot.

Ron