IN a small workshop in the hilly town of Yaoundé, the capital city of Cameroon, a set of unique machines roar day and night, helping produce one of the region's favourite dishes. These "robots", as their inventor calls them, allow operators to select, husk, grind and press pumpkin seeds, delivering the raw, husked seeds known locally as “egusi”, “ngondo” or “pistache". It took the inventor almost forty years to go from concept, to prototype, to filing an international patent, to finally producing his machines, which are the only made-in-Africa devices of their kind. “Apart from here, this kind of machine…