Pressure + temperature logger based on Adafruit feather.

parts:
  Adafruit feather 32u4 Adalogger (main board + SD-card)
  FeatherWing OLED 128x32 (display + 3 buttons)
  BMP180 breakout (pressure + temperature + altitude sensor)
  MCP9808 breakout (temperature sensor)
  DS3231 breakout (real time clock)
  + connectors
  + self-made PCB (see pcb folder)
  + box (see box3d folder)

Arduino libraries:
  Wire              (I2C)
  SPI + SD          (SD-card)
  Adafruit_BMP085_U (BMP180)
  Adafruit-GFX      (graphics) -- Not needed, use local smaller version instead
  Adafruit_SSD1306  (display)  -- Not needed, use local smaller version instead
  Adafruit_MCP9808  (MCP9808) -- Not needed, use low-level I2C instead
  RTClib            (DS3231)  -- Not needed, use low-level I2C instead

All libraries workes, but program size is too large if all of them are included.
Using a simplified local version of Adafruit-GFX + Adafruit_SSD1306 solves this problem

assembling:

It is good to use connectors between main board, display board and sensor board.
Then you can easily debug the device, fix it, or use the main board for something else.
Size of the device is larger in this case.
I used connectors for display but soldered the sensor board.