Keyestudio ARDUINO maker learning kit, Manual

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140
if (digitalRead(DAT)) // When DAT = HIGH IS FORWARD
{
COUNT++;
digitalWrite(LED1, HIGH);
digitalWrite(LED2, LOW);
delay(20);
}
else // When DAT = LOW IS BackRote
{
COUNT--;
digitalWrite(LED2, HIGH);
digitalWrite(LED1, LOW);
delay(20);
}
}
//////////////////////////////////////////////////////////
Result
Rotate the encoder, you can control the on and off of the two LEDs.
*******************************************************************************
Project 30: 5V relay
Introduction
Relay is an automatic switch element with isolation function. It's widely used in remote control,
remote sensing, communication, automatic control, mechatronics and electronic devices. It is one
of the most important control elements. In summary, it has below functions:
1)Expanding the control range: for example, when the control signal of the multicontact relay
reaches a certain value, it can form different contact ways. At the same time switch on or off of
multiple circuits.
2)Amplification: for example, sensitive relay and intermediate relay can control circuits of large
power using a small amount of controlled quantity.
3)Synthetic signal: for example, when input more than one specific control signals to multiwound
relay, achieve predetermined control effect after comparison and synthesis.
4)Automatic, remote control and monitoring: for example, combining relay on the automatic
device to other electric equipment can realize automatic operation.
Matters needing attention
a. rated working voltage: refers to the normal working voltage the relay coil needs,