The Raspberry Pi Sense HAT

If you are targeting the Astro Pi mission, it makes sense to get the Sense HAT as an add-on board for your tiny single board computer, the Raspberry Pi or the RBPi. With a fantastic RGB LED matrix, not only is the board beautiful to look at, but it also comes with a plethora of sensors on-board. That makes it useful for the applications in the International Space Station where it is headed to in December 2015.

The Sense HAT looks like an ordinary board with an 8×8 RGB LED matrix on it. You can use it to display graphical information in color. For example, using the display you can indicate geomagnetic North. Apart from the matrix, the Sense HAT also has a five-button joystick, which allows the user to interact with the programs the RBPi is running. That includes playing games such as Tetris, Snake or Pong on the RBPi.

The Sense HAT includes several sensors such as a gyroscope, accelerometer and magnetometer. It also has sensors to read ambient temperature, barometric pressure and humidity. A Python software library that comes with the board provides the user with an easy access to everything on the Sense HAT.

Using the software library, you can conduct a huge range of projects for the Sense HAT and RBPi combination. For instance, if you are traveling with the combination, it can measure and show your speed. At the same time, it can tell you the direction it is facing, how humid is the atmosphere nearby and even the temperature of your surroundings.

The Sense HAT kit comes with the fully assembled Sense HAT board, four mounting posts and eight screws so you can mount the HAT on your RBPi securely. Mounting the board on the RBPi is simple. First, fit the four mounting posts with four screws on the board. Now, align the 40-pin connector on the HAT to fit on to the GPIO connector of the RBPi and push in firmly. The four posts will align with the mounting holes of the RBPi. Secure those with the remaining four screws and you are done.

To install the software, visit the AstroPi and the Swag websites. Here, you can find out of the world projects, a host of ideas and instructions related to the RBPi and the Sense HAT, fit for the applications on the ISS or the International Space Station.

Technical specifications of the Sense HAT are impressive, considering the inexpensive setup. The Gyroscope measures angular rate at +/- 245/500/2000 dps. The Accelerometer measures linear acceleration at +/- 2/4/8/16 g. Temperature accuracy measured in the 0-65°C range is +/- 2°C. The Relative Humidity sensor has an accuracy of +/- 4.5% within the 20-80%RH range, with a temperature accuracy of +/- 0.5°C in the 15-40°C range.

You must take care while measuring temperature with the Sense HAT. When the LEDs are lit for some time, they, together with the board, tend to get warm. That heats up the air nearby and the measurement may not reflect the ambient temperature accurately.