In order to contribute towards making the teaching of physics more playful and less abstract, we conceived to develop an educational equipment called Planetary Scale. To build it, we used an Arduino microcontroller to assist the teachers of physics in their approach of the ratio between mass, weight force and normal force. To that end, this article constitutes the description of the building process of this educational resource, and the discussion of the purpose, carried out by accessible materials and free software, which can be reapplied by teachers in their routines. The Planetary Scale was designed to simulate the weight changes and mass invariance in any planet of our solar system, and has nine buttons to select the planet desired, in addition to the 'Reset' function. The device is an example of technology applied to physics education and was built to make it possible for the teacher to develop and use it in the classroom, in addition to act as an incentive to use new educational resources.