TAG
I2C works great on a breadboard demo and then starts failing once real cable lengths and motor noise show up. I now treat I2C reliability as a physical-layer problem first and a software problem second.
For greenhouse automation, I wanted a protocol that survives long cable runs and noisy environments. Modbus RTU over RS485 is still one of the best options for this type of deployment.
Mixed sensor stacks on Raspberry Pi frequently fail because of address collisions and inconsistent voltage assumptions. I now audit every module before wiring.
Small Arduino prototypes often fail when moved into real environments. The cause is rarely one major bug. It is usually the accumulation of power noise, slow memory leaks, missing timeouts, and weak recovery behavior.
Many embedded dashboards look stable only because noise is hidden by aggressive averaging. That is not the same as accurate measurement.
Unstable power is behind a large share of embedded bugs: random resets, noisy ADC values, communication drops, and drifting sensor readings. Good power design is often the highest-leverage hardware improvement.
Outdoor deployments fail more from enclosure mistakes than from firmware defects. A box that looks sealed on day one can trap condensation, stress connectors, and destroy electronics over time.
