Communication Protocols — question 1 of 10
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This is a common failure mode with low-cost microcontrollers that skip the external crystal to save BOM cost.
A board uses its microcontroller's internal RC oscillator (no crystal) to generate a UART signal at 115200 baud. Right after power-up, the text on your terminal reads perfectly. After the board has been running for a minute or two, the output degrades into garbled characters and stays that way. What's the most likely explanation, and how would you confirm it on the bench?