For as often as you eat this bread and drink the cup, you proclaim the Lord's death until He comes. (1 Corinthians 11:6).
Paul, on his way to Jerusalem has stopped at Troas. Here "on the first day of the week" he meets with the local church, and Luke directly states that the purpose of their gathering was "to break bread," i.e. to celebrate the Lord's Supper. This passage need not mean the Lord's Supper was the only purpose of their gathering, but it certainly is one prominent purpose and the one emphasized here. The centrality of communion to the weekly gathering is stated casually without explanation or defense, suggesting this practice was common among those Luke expected to read his account. These early Christians met weekly to celebrate the Lord's Supper (http://thegospelcoalition.org/blogs/tgc/2012/04/18/three-arguments-for-weekly-communion)