To make turmeric powder, dry the whole turmeric in the sun. Make sure, that there is no direct sunlight, otherwise the color of turmeric will be light.
Put the turmeric in the Imam dasta and cut it into small pieces to make it easier to grind in the grinder.
Put small pieces of dry turmeric in the mixer grinder and grind it finely.
Put the prepared turmeric powder in an airtight container and use it as per need.
Recipe by Indian Cuisine at https://www.indicuisine.com/turmeric-powder-recipe/