izzy84075 wrote: ↑Thu Sep 21, 2017 8:15 pm
Yeah, it's similar to what's on the LTAR display.
The circuit is something similar to this one, though I'm pretty sure this one is better than what I had figured out back then.
![Image](https://i.imgur.com/zn6m854.png)
The input from the iPod/LTAR goes in where the 40Hz source is in that, and the output from the op-amp is your input to whatever you're capturing with. Puts out nice clean square waves, as you can see on the left trace on the bottom.
I just tested this circuit, by the way. Works great! My cheap logic analyzer should be here anytime, and then I'll get some nice clean captures for you guys.
EDIT: Man, captures are much smaller when they're digital data instead of analog. Still putting new captures at
https://drive.google.com/drive/folders/ ... sp=sharing, the latest being the "loopback" one. I've got two of those op-amp circuits, one on each TX and RX, and am capturing the outputs with the cheap LA set to 50KHz. In this case, though, I've got the TX and RX lines bridged together, so both outputs are pretty much the same(Though I just noticed that I grabbed the wrong resistor for one part, which explains the difference between the two outputs. D1 is the correct channel.). There's a /ton/ of the 0x50 blocks in there, which I had never noticed existing before, haha.
EDIT 2: Pushed another decoder update. Had a couple typos in the code that were causing it to error. Also added a few more block names.
EDIT 3: Hrm. Having the iPod connected is making capturing more problematic, still. It works fine with just the LTAR with a loopback, but once I connect the iPod, the LTAR TX gets... muddled.
![Image](https://i.imgur.com/b91o1AL.png)