  Calculations of the elastic $I=\frac{3}{2}$ nucleon-pion scattering phase
shifts on two lattice QCD ensembles with $m_\pi=200\mathrm{MeV}$ and
$280\mathrm{MeV}$ are presented. The ensembles both employ $N_\mathrm{f} = 2+1$
Wilson clover fermions. We determine the $\Delta(1232)$ resonance parameters
from a finite volume scattering analysis. In one study the single partial wave
simplification is employed to compute the $p$-wave amplitude while in the other
we treat the partial wave mixing between $s$- and $p$-wave contributions.
Fitting our data to a Breit-Wigner resonance model we find $m_\Delta/m_\pi =
7.13(9)$ and $4.75(5)$ on the two ensembles respectively, showing that for a
lighter quark mass the resonance mass moves from near the $N\pi$ threshold to
near the $N\pi\pi$ threshold, in agreement with experiment.
