Excessive electromagnetic interference (EMI), a fried circuit board, an exploded battery, and faulty sensor readings: these all can result from a simple engineering error. To improve as a professional engineer or serious electronics maker, you must learn from your engineering errors, as well as the mistakes of others. In a new series called "Error Analysis", we share insights from Elektor community members about their engineering-related errors and what they learned from the experiences. And, of course, we highlight tips and tricks that will help you enhance your design, testing, and programming skills.