Thanks for the reply. The trouble is that the board becomes usable if I can maintain the cost. If the cost goes up as much as 1 $, it will lose the competitive edge.

The other problem got cleared. I need to send 1F instead of 8f. I actually reversed f8, and thought it was 8F. It should be 1f. Switching of 4051 takes place even when I send FF. But some how some channels are getting connected, and some are skipped. So I understand that it will not work properly.