9. Output devices

1.1 Assignments of the Week

1. Group assignment:
   • Measure the power consumption of an output device.
   • Document your work on the group work page and reflect on your individual page what you learned.
2. Individual assignments:
   • Add an output device to a microcontroller board you've designed and program it to do something.

1.2 Group Assignment

This is the link of our group assignment of this week where you can see the video of our experiment.

We used a DC Power Supply to measure the power comsumption of the DC motor. This DC Power Supply offers two modes of operation: constant voltage output (CV) and constant current output (CC). The output mode is determined by the voltage value and current value set by the user and the load connected by the user.

Observation:
We used CC mode to observe the change of voltage and the movement of the motor. The smaller the current, the smaller the voltage, according to P=I*V, the smaller the power consumption of the DC motor. When the current is less than 0.03A, the motor stops working.

1.3 Individual Assignment

I want to add a fan to my fab_xiao and control it with the button on the board.

1) View the Fan Specifications

I found its introduction and specifications on the purchase page of the fan. "Gravity: Fan module" by DFRobot

2) Connect to the board

3) Coding

When the button is pressed, the fan rotates at a high speed, and when the button is released, the fan rotates at a slow speed.

        void setup() {
          // put your setup code here, to run once:
         pinMode(A0,OUTPUT);
         pinMode(D7,INPUT);

        }
        void loop() {
          // put your main code here, to run repeatedly:
          int button_state = digitalRead(D7);
          if(button_state==HIGH){
            analogWrite(A0,255);
          }
          else{
            analogWrite(A0,50);
          }
        }