How do you approach working with equipment or systems that lack documentation?

If documentation is unavailable, the following approach can be used to work with equipment or systems:

1. Study available resources: look for any indirect data — sources, comments, forums, usage examples.
2. Analyze interfaces: examine available APIs, protocols, registers, if it is equipment.
3. Experimental testing: carefully conduct tests to understand the system's behavior.
4. Reverse engineering: if possible, analyze binary files, firmware, or signals.
5. Logging and monitoring: use logs and debugging tools to understand operation.

For example, when working with an unknown device, you can write simple code that sends commands and analyzes responses, gradually figuring out the interaction protocol.