Tag Archives: Pushbutton

RFID Lock and Unlock Demonstration Project Raspberry Pi Pico W

In this video lesson we explore using an RFID-RC522 and an RFID tag to lock and unlock our raspberry pi project. This demonstration will include an RGB LED which remains red while the system is locked, and then turns green when the system is unlocked by the RFID tag. Absence of user input, the system will lock again after 5 seconds. The following is the circuit diagram for the project:

RFID
Schematic for Raspberry Pi Pico W and RFID module, with LED and Push Buttons

When using the breadvolt, or any battery power supply on a breadboard project, do not turn the power supply on while the Raspberry Pi Pico is connected to USB, as you could generate voltage conflicts. It is an either or. If the USB is connected, the power supply should be OFF. Or if you are going to connect the USB, first turn off the power supply.

For your convenience, the code for the project is included below:

 

Arduino Tutorial 34: Simplest Way to Use a Pushbutton Switch

In this lesson we show you a quick hack that will allow you to incorporate a pushbutton switch into an Arduino project without having to use an external pullup resistor, and still get very stable operation. The trick is to create a digital input pin, which in our example is pin 2. We then digitalWrite that INPUT pin HIGH. What that does is put an internal pullup resistor on pin 2, and then connects it to 5 volts. In effect, we are using a clever command to use the Arduino’s internal pullup resistors. The code below is what we used in the video. Enjoy!

An official Arduino Uno R3 is available HERE. In this new series of lessons, I will be using the sensor and other components found in this KIT.

Arduino Tutorial 28: Using a Pushbutton as a Toggle Switch

In lesson 27 we learned how to incorporate a pushbutton into an arduino project. We learned how to utilize pull-up and pull-down resistors in order to incorporate a button into a circuit. The operation of the button in lesson 27 was pretty simple . . . if the button was held down, the LED would come on. When the button was released, the LED would turn back off. This is an interesting demonstration, but much more interesting is the case where we make a toggle switch. If you press and release the button, the LED comes on, and then if you press and release the button again, the LED goes off. While this sounds very similar to the previous case, it turns out to require a lot more thought. This video lesson explains how to think about this problem, and how to make it work.

If you want to follow along at home, an official Arduino Uno R3 is available HERE. In this new series of lessons, I will be using the sensor and other components found in this KIT.

Below is the code we used to achieve the toggle operation. The video gives details on how to connect up the circuit.