As long as relay is energized, the situation remains the same and NO and COM are connected. There by acting against spring tension due to magnetism. Due to this magnetism, the common terminal is pulled away from NC and now resides on NO. Whenever the coil voltage is applied between L1 and L2, the coil gets magnetized. If a relay is placed on a table, then the NC and COM terminals are connected to each other. The Common terminal is residing on NC terminal using a sprint tension. The terminal Common is a movable terminal and NC (normally closed) and NO (Normally open) are fixed terminals. Whenever the coil is given with voltage, it acts as an electromagnet. The L1 / L2 can be connected directly to a DC voltage source. L1 and L2 are the points of an eletro-magnetic coil which acts as a magnet inside relay. Relay as Switching CircuitĪs can be seen in above image, a simple relay is having 5 terminals So connecting an AC Device needs something different.
![codevision avr examples hc-sr04 codevision avr examples hc-sr04](http://ezdenki.com/graphics/hc-sr04-s.jpg)
You can’t connect any other output device directly to the pin of raspberry pi, not even a DC motor. It means, we can interface an LED directly to raspberry pi gpio pin, and thats about it.
![codevision avr examples hc-sr04 codevision avr examples hc-sr04](https://image.slidesharecdn.com/fvee9404note-160306141628/95/avr-codevisionavr-20-638.jpg)
In fact the 3.3V generated on output pin is also current limited so it cannot deliver more than 20 mA current from that pin. But this output voltage is very low to turn on any physical devices. Similarly, when writing logic 1 on the pin, a +3.3V appears on the pin of Raspberry pi.īy writing a program we can generate logic 0 (gnd) or logic 1 (+3.3v) on any output pin of raspberry pi. Practically, when writing a program for writing logic 0 on the pin of raspberry pi, an actual 0 volt or GND potential appears on the pin. These logic output is called as logic 0 and logic 1. Raspberry Pi being a digital computer, can generate logic outputs on the GPIO pins. If you’ve experimented on raspberry pi, then you must know that raspberry pi has a GPIO, meaning general purpose input/output port pin.Īs you can see in the above image, the 40-pin GPIO is useful to interface a wide variety of output devices. In this tutorial, we’re going to see exactly how we can interface a real world device with raspberry pi to perform switching.
![codevision avr examples hc-sr04 codevision avr examples hc-sr04](https://circuitdigest.com/sites/default/files/projectimage_mic/AVR-Ultrasonic-Sensor.jpg)
CODEVISION AVR EXAMPLES HC SR04 HOW TO
The possibilities are literally limitless if we know how to perform this. Real world applications, where raspberry pi can turn on / off a device by receiving commands either from internet of via some sensors or via a mobile phone application talking to pi using Bluetooth. If you’ve been working on raspberry pi for some time now, you must be thinking about how to make it useful in real world applications, right? Keep experimenting!!! How to interface relay with raspberry pi to switch AC devices This is the detailed tutorial of Ultrasonic Sensor Interfacing with Raspberry Pi
CODEVISION AVR EXAMPLES HC SR04 CODE
Raspberry pi ultrasonic sensor interfacing circuit Python Code for Ultrasonic Sensor Interfacing with Raspberry Pi import RPi.GPIO as GPIOĪbove code is created in Python 3, however if you’re using python 2 the code will still work for you.