During the early stages of development, the 24V DC boost converter used for driving the blower fan was initially placed on the processor board.

While this simplified wiring during prototyping, it introduced several unintended issues during operation.

The boost converter, being a switching power supply, generated noticeable electrical noise and transient disturbances. Since it was located on the same board as the ESP32 and control circuitry, these disturbances began to affect system stability.

Symptoms included occasional erratic behavior in control signals and increased susceptibility to noise, especially during fan startup and rapid load changes.

Further analysis indicated that combining sensitive control electronics and high-current switching circuitry on the same PCB was not ideal for this application.

To address this, the 24V booster was relocated to the power board.

This change provided several advantages:

• Improved physical separation between noisy power circuitry and sensitive control electronics • Reduced noise coupling into the ESP32 and sensor interfaces • Better grounding and current return paths • Simplified routing of high-current traces

After relocating the booster:

• System behavior became more stable
• Noise-related issues were significantly reduced
• Overall reliability improved

This modification highlighted the importance of proper partitioning between power and control domains, especially in mixed-signal embedded systems.

Separating high-frequency switching circuits from low-level control electronics can greatly improve system robustness.

Would be interested to know how others handle power and control separation in similar mixed-signal designs.