Help with SysEx string formatting for Roland DEP-5 panel #721
Description
Hello everyone,
I'm currently building a Ctrlr panel for the Roland DEP-5, and I’ve been able to make some progress—basic MIDI communication is working, and I can send and receive SysEx data to/from the unit. However, I’m struggling with how to correctly format the SysEx strings in the "Custom MIDI Message" field of each modulator.
I understand the basics, like using F0 ... F7, and that I can insert variables like ms, ls, or value where needed. But I’m not entirely sure how Ctrlr handles these internally, or how to correctly position the value bytes inside the message. Also, how do I handle fixed bytes that shouldn’t change (should I use XX for those?), and how do I ensure the checksum is calculated correctly?
For example, I want to control the Reverb Time parameter, which seems to be located at a specific byte offset in the DEP-5’s All Parameter Receive (APR) message format. Here's the SysEx structure I’m using:
F0 41 35 00 52 20 01 <0X XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX ms ls XX XX> F7 <string
The format in the manual is set to 0vvv vvvv : 0vvv vvvv (in a 24 bytes format string), and in this case what I want to change is in the bytes 21/22. It's says something about nibble pairs, but I really don't understand.
Can somebody help me with this?
Thanks in advance!