Timing errors

• MCU clock drift

Software constants for calculating time may not accurately represent the actual clock frequency of the hardware (e.g. 16MHz vs 16.01MHz).

This will cause drift - clock will become more inaccurate over time.

Drift can me mitigated by measuring sufficiently small time differences.

• MCU clock precision

Precision at which software can read the clock.

• Communication latency

Delay between request and response over a communication medium. Theoretical, you can only calculate the round-trip delay. A weighted average can be used to determine the delay in one direction. Usually the delay is assumed to be symmetric (the same in both directions). See NTP.

• Server clock drift

• Server clock precision