You can check out the bus timings from Hyderabad to Vijayawada by using this convenient bus app. You will also see links which will help you make advance bookings for your travel. Hope this helps!
And just in case you are planning a trip to Vijayawada, don't forget to check out the famous tourist attractions here. Some of these include Kanaka Durga Temple, Undavalli Caves, Bhavani Island and many more.