Digital Signals
A digital signal is interpreted as discrete logic states, even though the physical voltage changes continuously. Firmware sees these states through input circuitry and controls them through output drivers.
CORE IDEA
HIGH and LOW are voltage ranges, not ideal mathematical points
ENGINEERING VIEW
Rise and fall time affect real signals
WHAT TO CHECK
Noise can create false transitions
REMEMBER
Always check the MCU's electrical specifications
Engineer’s checklist
- HIGH and LOW are voltage ranges, not ideal mathematical points
- Rise and fall time affect real signals
- Noise can create false transitions
- Always check the MCU's electrical specifications
KEY TAKEAWAY
Digital behavior is physical behavior. When firmware and expectations disagree, measure the signal instead of guessing.