AllenNeuralDynamics / harp.device.white-rabbit

A 16-output Harp clock synchronizer
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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.

PCB

Features

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. PPS 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. AUX_UART Error from the nominal Harp time is < 3[us].

AUX_UART_ERROR

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.