I first added my newly burned ATMEGA328 and programmed it. Then I added the pressure sensor.
The pressure sensor has solder pads under the chip! yikes! I used solder paste and a toaster oven.
I needed to reflow the solder because the first time the BMP180 did not fully seat, so I re-heated the board removed the chip, cleaned the board, added more solder past and reflowed the chip - ah much better.