A project log for wireless microphone digital

developing a digital wireless radio mic in both 2.4ghz and UHF

ben bilesben biles 08/10/2016 at 02:240 Comments

ok finally i have horrible sounding audio streaming in to the reciever in 48 byte packets made of 8bit samples. 1 every 4 samples is sent from the TX.

my mistake was believing that this code would determin if I had a

packet recieved or not. It turns out it was pumping out multiples of the

same recieved packet causing a horrible ringing sound.

if (rf24module1.available())
uint8_t len = 48;
if (rf24module1.recv(packetmod1, &len))

I have now numbered the packets, so first byte in packet has a number from 1 to 255 and I test that if packetnumber != packetnumber then ignore the packet :)

It audio sounds like rubbish of course but that is

to be expected. the samples are being pulling in by the I2S codec from

the recieved samples in the circular buffer and this appears to work ok.

I also found that my home made radio config was not working at all so now I have reverted to using a canned config in the radiohead driver.

its tricky making your own config with the SI software and then editing the template in radiohead. you can't just replace the config file with the generated one from the software. basically its a lot of time working out which registers your allowed to change and which have to stay the same and even then it might now work at all.. mmm

I might just stick with the GFSK Rb = 150kbs, Fd = 300kHz pre made config for now

and try and impliment IMA_ADPCM again now the link is working :)

then I will enable true diversity recieving and do some range tests.

So far range is looking good even with just one reciever !