board.md

Astro Pi: what is it?

Astro Pi is a competition and a mission. Two specially adapted Raspberry Pis will be travelling to the International Space Station (ISS) with British ESA astronaut Tim Peake. The Raspberry Pis will include an add on board called the Sense HAT which has the ability to sense a wide variety of conditions and provide output via the built-in LED matrix. You can find out more about the mission and the board by watching the official Astro Pi competition video:

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Here is NASA astronaut Reid Wiseman giving a fly-through tour of the ISS:

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What's on the board?

Let's take a tour of the main features of the Sense HAT:

The main features are highlighted in red.

1. The LED matrix on the left has 64 light emitting diodes (LEDs) arranged in an 8 x 8 grid. On board the ISS the Raspberry Pi cannot be connected to a screen as the astronauts only have laptops, so the LEDs on the Sense HAT act as a display. They can be used to display shapes, icons and messages to the crew of the ISS.
2. Next is the inertial measurement unit (IMU). All spacecraft have these since they're very important for space flight. It's the small microchip just above the text ACCEL/GYRO/MAG on the Sense HAT. It's actually three sensors in one:

• An accelerometer to measure the force of acceleration (like in a Wiimote)
• A gyroscope to measure orientation (so you know which way you're pointing)
• A magnetometer to measure the Earth's magnetic field (like a compass) So this is basically a movement sensor and will allow you to measure how you're moving the Raspberry Pi in your hand or, in space, how the ISS itself is moving.

1. Next is a humidity sensor. This will allow you to measure air moisture. It's the small chip just below the text HUMIDITY. You can also use it to measure ambient temperature.
2. There is also a pressure sensor for measuring air pressure, something which is certainly important in space. It's the chip to the right of the text PRESSURE.
3. Last but not least is the joystick. The Raspberry Pi cannot be connected to a USB keyboard or mouse in space, so the Sense HAT has its own five button joystick. This is the silver rectangle in the bottom right corner with the small stick poking out of the top. It can move up, down, left, right, and allow middle-clicks.

What's Next?

Now that you're familiar with the Sense HAT board, you should assemble it and connect it to your Raspberry Pi.