How I leared what a decoupling capacitor is for, the hard way

11 hours ago

A new PCB with a magnetometer had issues where the Z axis read constant values.
Plugging the drone into a battery caused the magnetometer to stop working entirely.
Investigations showed voltage ripples from a switching regulator were causing noise.
Decoupling capacitors were identified as a solution to absorb high-frequency noise.
Without a decoupling capacitor near the magnetometer, a permanent fix wasn't feasible.
An external magnetometer via a Qwiic connector was used as a temporary solution.
Testing demonstrated how decoupling capacitors clean up noisy power signals.
Despite some ICs working without decoupling caps, it's best practice to include them.
The experience highlighted a valuable learning opportunity in PCB design.

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