they’re decently sized component vessels for pocket builds such as [rgco]’s portable magnetometer, especially if you can get the 100-count box. Best of all, they’re see-through! Sure ...

If you fancy building your very own DIY magnetometer you may be interested in a Arduino project published to the Instructables website by maker Markus Opitz. His magnetometer costs less than €50 ...

and a magnetometer. Each sensor can be communicated with using I2C from analog pins 4 and 5 on the Arduino Uno. We powered the sensor stick using the 5 volts out available on the Arduino Uno.