Sweet pea seeds

Good afternoon everyone,

I grew sweet peas from bought seed this year and they've all done really well. I have picked hundreds for the house over the summer but, a couple of weeks ago, I stopped picking them in order to let the seed pods form. Although there are still masses of flowers I now also have the pods. They are still soft and green. Could anyone point me in the right direction as to how I will know when they are ripe and ready to harvest?

Thanks, in anticipation.