audio

[ben]

Is it possible to input line level analogue audio or digital audio of some kind into the ADC for transmitting with BladeRF?
can the audio then be decoded with the DAC and output as line level analogue audio or some kind of digital audio through a second BladeRF?

I am trying to make a gsfk modulated audio link in bandwidths of 200khz each on 10 channels between 606.5mhz and 613.5mhz at between 10 & 125mw output power.

are multiple audio channels possible? or just stereo?

if answer = yes ( in a simple way ) then can these boards do this in stand alone mode ? running from fpga ? switch frequencies with the gpio addon board?
maybe even add a small display or row of LED's to see what frequency each board is on?

could I load different audio compression codecs into the FPGA

I was about to embark on building this with some AD IC's when I stumbled across BladeRF ! would be great if this is achievable with this board since I could reconfigure frequencies when needed!

lastly, is there a way to calculate power usage of this board? Would like to run board on DC rechargeable battery's..

anyone done his before?

hope i have posted this in the correct part of this forum,

thanks, Ben

[drmpeg]

You can't send analog audio directly to the bladeRF. However, you can use the bladeRF to take care of the RF portion of your project. In fact, one bladeRF could provide all ten channels. Also, at 200 kHz bandwidth, you could just send wide deviation FM (just like broadcast FM).

Here's an example of bladeRF sending mono audio (from a file) over multiple channels. In this case, it's sending Narrowband FM at 440.9 MHz, Wideband FM at 441.0 MHz, AM at 441.120 MHz, LSB at 441.131 MHz, USB at 441.134 MHz, CW at 441.140 MHz, and PSK31 at 441.142 MHz.

https://github.com/argilo/sdr-examples

Here's a pic of the (modified) GnuRadio flowgraph from the above link. It's showing just the top part which has wideband FM, narrowband FM and AM.



Ron

[ben]

Thanks for the speedy reply Dr.mpeg

So to test BladeRF in my mobile audio PTP project I would need to run 2 x ARM boards running linux / GNUradio / BladeRF usb driver ( or equivalent )

the GNUradio software modulates audio inputs from an ARM board into FM or even FSK digital modulation? can audio be modulated with FSK or would that need to be encoded / streamed with gnuradio tcpip PTP??

I only need to use one frequency at a time at the transmit side and multiple on the receive side..
there would will ultimately be 5+ small audio transmitters and one multichannel receiver with multiple audio device outputs.

Is GNUradio cpu heavy? what kind of spec ARM board would be ideal? the devices will be mobile so power is a concern!

Also has anyone experimented with the idea of 'true diversity' on the receive side to avoid RF dropout ? guess that question should be another post!

OK, time to download GNUradio and see if i can open/close configs from command line to switch RF frequencies...
will need some way to switch operating frequencies from ARM board...

will report back if i get any of this to work..

BEN