First thing we need to get the components!

1. You can pick up a 3V Pro Trinket at http://store.hackaday.com/products/trinket-pro-with-black-solder-mask-and-the-hackaday-io-logo or Adafruit $10 (3v not the 5v since the BMP 180 needs a vcc of 3.3v)

2. BMP 180 Barometric Pressure Sensor https://www.sparkfun.com/products/11824 $10

3. HP QDSP-6064 bubble display https://www.sparkfun.com/products/12710 $3

4. 4 X 330ohm resistors https://www.sparkfun.com/products/11507 $1

Let's begin by making sure the Pro Trinket is correctly installed and working. Then we will install the necessary libraries to get the code to work.

1. If you are already familiar with the Pro Trinket or are planning on using an Arduino UNO or Pro Mini skip to step 3.

2. To get the Pro Trinket to work with the Arduino IDE you have two options: Either install the Adafruit IDE ( almost exactly like the Arduino IDE but automatically supports the Pro Trhinket) or add the hardware files to your Arduino folder. Download links and instructions are here: https://learn.adafruit.com/introducing-pro-trinket/setting-up-arduino-ide

3. Now on to downloading and installing the libraries used by the sketch:

I. BMP 180 library from Sparkfun https://learn.sparkfun.com/tutorials/bmp180-barometric-pressure-sensor-hookup-/installing-the-arduino-library

II. Seven Segment Display Library: https://github.com/sparkfun/SevSeg

Now on to hooking up the hardware.

for the BMP 180,

• 3.3V to VCC (5v will fry the BMP 180)
• GND to GND
• Analog 4 to SDA
• Analog 5 to SCL

For the display,

in the format Microcontroller Pin to Bubble Display pin:

• D8 to P1
• D5 to P10
• D11 to P4
• A1 to P6
• D14 to P12
• D6 to P11
• D10 to P3
• D3 to P8
• D9 to P2
• D4 to P9
• A0 to P7
• D12 to P5

Display Pinouts:

Download the code: https://github.com/sergioser/Portable-Altimeter-Logger-with-Display.git

Upload the code and run!

That's it enjoy!

Do not hesitate to post any qyestions, suggestions or comments!