View source for Experiment 8: Optocoupler Relay Experiment

*[[Basic Experiment Kits For Arduino]]
*[[Basic Experiment Kits For Raspberry Pi]]
== 接口说明 ==
*VCC: Positive terminal for DC power supply of the module
*GND: Negative terminal for DC power supply of the module
*IN: Relay signal trigger terminal (can be set to high or low level to control relay activation)
Relay Trigger Mode Selection Terminal: When the DIP switch is set to L, it is triggered by a low level; when set to H, it is triggered by a high level.
*NO: Normally open interface of the relay, open before the relay is activated, and short-circuited to COM when activated
*COM: Common interface of the relay
*NC: Normally closed interface of the relay, short-circuited to COM before the relay is activated, and open when activated


== Arduino ==
=== Experimental Phenomenon ===
* The relay is energized once every second, and simultaneously, the LED indicator on the module lights up every second.

=== Circuit Connection ===
*[[File:实验八：光耦继电器实验_接线1.png|400px]]

=== Reference Program ===
<pre>
int relay = 2; // Relay activation trigger signal - high level active；
void setup()
{
 pinMode(relay,OUTPUT); // Define port as output；
}
void loop()
{
 digitalWrite(relay,HIGH); // Activate relay；
 delay(1000);
 digitalWrite(relay,LOW); // Deactivate relay；
 delay(1000);
}
</pre>

== Raspberry Pi ==
=== Circuit Connection ===
*[[File:实验八：光耦继电器实验_接线2.png|400px]]

=== Program Execution ===
==== Python ====
* Install the gpiozero library
** You can install the library using the following commands:
<pre>
sudo apt update
sudo apt install python3-gpiozero
</pre>
:* For other systems on the Raspberry Pi, you can install the library using:
<pre>
sudo pip3 install gpiozero
</pre>
:* Run the following command to view the GPIO pin definitions on the Raspberry Pi:
<pre>
pinout
</pre>
*Download the Raspberry Pi reference examples, unzip the files, copy them to your user directory, and run:
<pre>
cd raspberrypi/8/python_gpiozero
python relay.py
</pre>
*You should now see the Raspberry Pi running the optocoupler relay program correctly. To exit, press ctrl+C.
*Command explanation: '''gpiozero.LED(pin, pwm, active_high, initial_value)'''
** Main parameters:
*** pin: GPIO pin number,
*** active_high:
**** When set to True (default), connect the LED's negative terminal to GND and the other terminal to the GPIO pin.
**** When set to False, connect the LED's negative terminal to the GPIO pin and the other terminal to the 3.3V pin.
*** initial_value:
**** If False (default), the LED initial state is off.
**** If None, the LED pin is in an unstable state.
**** If True, the LED initial state is on.
*For more commands, please refer to the [https://gpiozero.readthedocs.io/en/latest/installing.html gpiozero documentation]

== Example Download ==
* [[:File:Basic Experiment Kits For Arduino.zip|Arduino Example Programs]]
* [[:File:Basic Experiment Kits For Raspberry Pi.zip|Raspberry Pi 5 Example Programs in Python]]

== Related Examples ==
{{Arduino and Raspberry Pi Case}}