  A numerical scheme utilizing a grid which is staggered in both space and time
is proposed for the numerical solution of the (2+1)D Dirac equation in presence
of an external electromagnetic potential. It preserves the linear dispersion
relation of the free Weyl equation for wave vectors aligned with the grid and
facilitates the implementation of open (absorbing) boundary conditions via an
imaginary potential term. This explicit scheme has second order accuracy in
space and time. A functional for the norm is derived and shown to be conserved.
Stability conditions are derived. Several numerical examples, ranging from
generic to specific to textured topological insulator surfaces, demonstrate the
properties of the scheme which can handle general electromagnetic potential
landscapes.
