This paper presents a bare-metal implementation of the IEEE 1588 Precision Time Protocol (PTP) for network-connected microcontroller edge devices, enabling sub-microsecond time synchronization in automotive networks and multimedia applications. The implementation leverages the hardware timestamping capabilities of the microcontroller (MCU) to implement a two-stage Phase-locked loop (PLL) for offset and drift correction of the hardware clock. Using the MCU platform as a PTP master enables the distribution of a sub-microsecond accurate Global Positioning System (GPS) timing signal over a network. The performance of the system is evaluated using master-slave configurations where the platform is synchronized with a GPS, an embedded platform, and a microcontroller master. Results show that MCU platforms can be synchronized to an external GPS reference over a network with a standard deviation of 40.7 nanoseconds, enabling precise time synchronization for bare-metal microcontroller systems in various applications.