micro:bit Project 2: What Makes Our Machine “Come to Life” Interactive devices

Interactive devices

In the next few chapters, we'll build some interactive kits projects, starting with lighting a single LED and displaying some cool rainbow LED Strips and music settings. These kits can also be categorized as "interactive device." In order to help you understand the mechanics better, firstly we need to explain how they are constructed.

The simplest interaction device consists of 3 parts:
Input unit for command acceptance or data collection
Control unit for data processing or signal processing
Output unit for sending data or executing actions

What are the functions of these units? Taking ourselves as an example, we collect information in the form of light, sound, taste, and power through our eyes, ears, nose, and skin. These information enter our brains and determine what response to take. Ultimately, we take concrete actions based on these information to change the physical environment. Specifically, your friend, for example, says "hello" to you, and you respond "hello". Here, your ears act as input components, your brain acts as a control module, and your mouth plays the role of output unit.
Similarly, in the micro: bit project, we use a variety of sensors as the input units, the mainboard as the control unit, and the actuator as the output unit.

Input Unit —— Sensor
Sensors (also called transducers) are physical components that detect the environmental characteristics such as light, temperature, humidity, etc. and convert them into signal data. In this tutorial, sensors such as buttons, sound sensors and temperature sensors are used..

Control Unit ——mianboard of Micro: bit
The mianboard of Micro: bit acts as a control unit here, using the signal pins to establish the connection between the input unit and the output unit and processing the data in the calculation processing module.

Output Unit —— actuator
The actuator is the one responsible for moving or controlling a system or mechanism. It converts electrical energy into motion, sound and light. In this tutorial, the actuators such as LEDs, small fans and servos are used.

Relationship between Program and Hardware
The input unit, control unit and output unit mentioned above are hardwares. As for human-being, the hardware is the body. However, the brain is more important because it produces ideas and controls every single action of us. The program here is like our brain. Both the body and the brain are indispensable for each person.

The Expansion Board of Micro: bit
The expansion board can extend buttons, switches, power interface and other module interface.
The modules can be directly connected to the expansion board, which makes the loop act more quickly and efficiently, and the micro: bit more powerful.