Let O-K be a 2-adic discrete valuation ring with perfect residue field k. We classify p-divisible groups and p-power order finite flat group schemes over O-K in terms of certain Frobenius modules over G := W(k)[[u]]. We also show the compatibility with crystalline Dieudonne theory and associated Galois representations. Our approach differs from Lau's generalization of display theory, who independently obtained our result using display theory.