Combine the flour, sugar, baking powder, baking soda and salt.
In a separate bowl, combine the buttermilk, butter and eggs. Add the flour and mix until just combined. Add the blueberries and fold into the batter.
Spray a waffle iron with non-stick cooking spray. Spoon about ¾ cup batter into each waffle section. Close the iron and cook for 6-8 minutes, until they are golden brown. Transfer to a plate, or a cooling rack, and repeat with the remaining batter.