Next installment...
Now I've connected the mixer and the controller to a breadboard and have the signal analyser effectively listening in to the conversation.
From the conversation, it appears that there's a lot more going on than the single "packet" from the previous post. Having seen the data in the conversation I've measured the smallest pulse and it's about 0.1 ms which (according to here) correlates with a baud of 9600.
So, with that in mind I added a UART protocol decoder (according to here, it's the only protocol decoder that mentions RS485) and set the settings in PulseView as shown in uart.png, started reading data and then turned on the mixer. After a period of time I turned off the mixer and stopped reading data.
The attached file (sample.png) shows the first 11 chunks of data.
A couple of things of note before getting to the data:
- There is about 39.15 ms between the end of one chunk to the start of the next chunk.
- PulseView seems to suggest there are a lot of Frame Errors but that may be because the protocol isn't really UART... perhaps
It looks like there are 7 bytes from the mixer (As there were 7 peaks in my last post) followed immediately by 7 bytes from the controller.
Only the final byte from the mixer ever appears to contain any data but then I haven't pressed any buttons on the controller yet.
The data is as follows:
00 00 00 00 00 00 00 00 00 00 00 00 02 00
00 00 00 00 00 00 41 33 F2 02 16 07 02 00
00 00 00 00 00 00 B3 33 F2 02 16 07 02 00
00 00 00 00 00 00 21 33 F2 02 36 07 02 00
00 00 00 00 00 00 B3 13 72 02 36 07 02 00
00 00 00 00 00 00 41 13 72 02 16 07 02 00
00 00 00 00 00 00 B3 33 F2 02 16 07 02 00
00 00 00 00 00 00 04 33 F2 02 16 07 02 00
00 00 00 00 00 00 53 33 F2 02 36 07 02 00
00 00 00 00 00 00 24 13 F2 02 36 07 02 00
00 00 00 00 00 00 B3 13 72 02 36 07 02 00
I can definitely see a pattern there but I'm unsure what it means just yet.
The next thing I'll be trying is to see if I can replicate the data sent by the mixer using an arduino or it'll all be for nothing...
