  This paper presents an observer-based event-triggered boundary control
strategy for a class of reaction-diffusion PDEs with Robin actuation. The
observer only requires boundary measurements. The control approach consists of
a backstepping output feedback boundary controller, derived using estimated
states, and a dynamic triggering condition, which determines the time instants
at which the control input needs to be updated. It is shown that under the
proposed observer-based event-triggered boundary control approach, there is a
minimal dwell-time between two triggering instants independent of initial
conditions. Furthermore, the well-posedness and the global exponential
convergence of the closed-loop system to the equilibrium point are established.
A simulation example is provided to validate the theoretical developments.
