I had been sitting there for a while (traffic light sensors dont pick me up...), and had arrived before he was in eyesight of the intersection (there is a hill that crests, and declines before the intersection, so the light is within sight from behind the crest of the hill, but I was not visible until he crested the hill)

What am I supposed to do? Hold out my arm until the light turns green? I was clearly waiting at the light, was courteous to give him room to stop in his normal spot, and once the light turned green, I clearly had noticed (I put my foot back on the pedal and started to move, albeit slowly). If he had looked at the situation, he could tell I was waiting for traffic...