Problem Description: Hello, we’ve encountered an issue and would appreciate your support: With the KT148A chip, after powering on, sending the code rarely triggers playback. However, if we use tweezers to briefly short Pin 4 (PB0) to ground and then send the code again, playback works normally. What could be causing this? Based on the observed behavior, it’s highly likely an issue with the timing of one-wire communication, particularly with the start signal, which may be too short. Let’s analyze this in detail and review the KT148A schematic as follows: 1. Pin 4 (PB0) of the Chip: PB0 is a test pin with the default factory function of triggering wake-up and playback when grounded. 2. Customer Description: When the customer uses tweezers to short PB0 (Pin 4) to ground, it follows this principle. The shorting action actually performs two operations: Action 1: The KT148A detects a falling edge signal, wakes up, exits low-power mode, and enters full-speed operation. Action 2: Th...
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