RIght on Riley! You've done a great job! The wiki layout of the data blocks is much easier to understand than on the forum. Nice work

I'm thinking maybe that third data frame in the 0x20 block is a salt or a nonce for the DRM. No. 0x20 is unrelated to authentication. It looks like the 0x20 blocks are in response to 0xC0 and 0xA0. Since it happens every 10 seconds it might be the idevice polling to see if the LTAR is still connect...

You are correct on that assumption. Play some music into the right channel, it's easy to confirm

Thank you. I appreciate you taking the time to draw up the schematic and post it.

No just mono input. I have a laptop with stereo input and that's where all of this originally started. I could never get it to record both devices. The way I have above works fine, I just have to post process the recordings so they start at the same time. I'll give your suggestion another shot to se...

Picture is probably easier. The splitter from the LTAR (Right channel disconnected) is how I record the iPod communication, and the splitter from the iPod is how I record the LTAR communication... It's been a while since I've messed around with this setup too. Once I got it recording both devices I ...

Ryan, I have a question about recording from the iDevice. The way I have been doing it is to disconnect the right channel from the input to the sound card so it's just floating. I think I've tried other ways too, i.e. disconnecting ground and right channel. It records ok, but is there a better way t...

Wow! This is going really well so far! Ryan, thanks again for all the decoders and for the hints as well. I had intended to start some analysis last night, but I found that the TRRS splitter that I ordered doesn't allow me to connect well with the LTAR. It is a 4-pole female to 2 male splitter. I t...

Yeah, I understand what you mean! I just reread what I posted annnnd it's confusing! Haha, thanks anyway!

I wasn't saying it was a checksum, I was trying to figure out if it was calculated in a similar way as the checksum. I.E. counting milliseconds from some point when a packet was sent or confirmed. Good to know I was looking at it from the wrong angle! Thank you.