An RP2040-based 16-output Harp-compliant Clock Synchronizer.

This device can serve as a drop-in replacement for the Harp-Tech Clock Synchronizer with added capabilities.

Features

• 16 output channels for distributing clocks to other devices
• 1 input channel for receiving and synchronizing to another clock source
• PPS output
• serial output of the time at user-specifiable baud-rate
• "Used channel detection." Device can identify which channels are in use.

Auxiliary Output

This device features an auxiliary output that can either produce a pulse-per-second (PPS) or UART message at the start of the whole second. This external signa enables Harp devices to additionally further synchronize with non-Harp devices.

PPS Output

This device optionally outputs a 1[Hz] signal with a 50% duty cycle on the whole second. Error from the nominal Harp time is < 1[us].

This feature is available on the AUX Port (3-pin terminal block).

AUX UART Output

This device optionally outputs a the current time in seconds at the start of the whole second. Error from the nominal Harp time is < 3[us].

This feature is available on the AUX Port (3-pin terminal block), and the baud rate is configurable via Harp Protocol (U32 in Register 36).

Developer Notes

In the firmware's CMakeLists.txt, adding (or uncommenting) the debug message below:

add_definitions(-DDEBUG)

will override the Auxiliary port behavior to use the auxiliary uart for printf-style debug messages. PPS and AUX UART features will not be available in debug mode.