Arduino 1.8.5 high low reference pin
Here to turn on the Relay with Arduino we just need to make that Arduino Pin High (A0 in our case) where Relay module is connected.
#Arduino 1.8.5 high low reference pin driver
A Relay module is easily available in the market with all its Driver circuit on the board or you can create it on perf board or PCB like below. Every Inductor coil produces equal and opposite EMF when switched OFF suddenly, this may cause permanent damage to components, so Diode must be used to prevent reverse current. And Diode is used to prevent reverse current flow, when the transistor is switched OFF. The resistor is used to provide biasing to the transistor. Transistor is used to amplify the current so that full current (from the DC source – 9v battery) can flow through a coil to fully energies it. The relay is always configured by using a small Driver circuit which consists a Transistor, Diode and a resistor. Relays are available in many ratings, here we used 6V operating voltage relay, which allows 7A-250VAC current to flow. When there is some voltage applied to the coil, the electromagnetic field produced, which attracts the Armature (lever connected to spring), and COM and NO (normally open contact) gets connected, which allow a larger current to flow. STM32F103 with HID bootloader The HID bootloader is a compact, driverless bootloader capable of flashing over USB. When there is no voltage applied to the coil, COM (common) is connected to NC (normally closed contact). Alternatively, set the 'boot 0' pin to low and 'boot 1' pin to high to stay in the bootloader after a reset.
![arduino 1.8.5 high low reference pin arduino 1.8.5 high low reference pin](https://i.stack.imgur.com/LFslW.jpg)
If you want to blink pin 13 on your Mega 2560 you need to make a few changes: Change line 12 of blink.S from: sbi DDRB,5 to: sbi DDRB,7 Change line 18 of blink.
![arduino 1.8.5 high low reference pin arduino 1.8.5 high low reference pin](https://i0.wp.com/randomnerdtutorials.com/wp-content/uploads/2017/10/Slide14-i.jpg)
Commonly used Relay is Single Pole Double Throw (SPDT) Relay, it has five terminals as below: That pin is pin 13 on the Uno/Nano/Pro Mini Arduino boards but on the Mega 2560 PB5 is pin 11.
![arduino 1.8.5 high low reference pin arduino 1.8.5 high low reference pin](http://www.robgray.com/temp/Due-pinout-A3.png)
A relay is a good example of controlling the AC (alternate current) devices, using a much smaller DC current. Means by applying small current we can switch ON the relay which allows much larger current to flow. Relay is an electromagnetic switch, which is controlled by small current, and used to switch ON and OFF relatively much larger current.