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Arduino Hardware Reset Circuit Breadboard
This circuit uses one pin to let you reset your Arduino in code. It pulls reset low for a couple milliseconds to ensure the Arduino has enough time to complete its reset cycle.
- ArduinoReset.sch - Arduino Reset EAGLE Schematic
- ArduinoReset.brd - Arduino Reset EAGLE Board
- Arduino Reset.zip - Arduino Reset Gerber
- Arduino_Reset.pde - Arduino Reset Example Sketch
Bill of Materials
|Qty||Part #||Description||Schematic ID||Source|
|1||NE555P||TIMER SINGLE PRECISION,DIP8 ,0.5MHZ||IC1||Source|
|1||CF14JT100R||1/4w 100 ohms 5% Carbon Film Resistors||R4||Source|
|1||CF14JT1K00||1/4w 1K ohms 5% Carbon Film Resistors||R3||Source|
|1||CF14JT10K0||1/4w 10K ohms 5% Carbon Film Resistors||R2||Source|
|1||CF14JT100K||AXIAL CARBON FILM RES 1/4W 100K OHMS 5% LF||R1||Source|
|1||EEA-GA1HR10||CAP ALUM 0.1UF 50V 20% RADIAL||C1||Source|
|1||SR215C103KAR||CAPACITOR, 0.01UF, 50V||C2||Source|
|1||2N3904BU||TRANSISTOR, NPN 200MA TO-92||Q1||Source|
Put a 100 ohm resistor between the emitter of the transistor and ground. This resistor limits the current that is sourced from the Arduino's reset pin. If the current got too high it could damage either the Arduino or the transistor Q1.
Insert a 1k ohm resistor between the base of the transistor and pin 3 of the IC. This resistor limits the current flowing into the base of transistor Q1. Transistors only need a small amount of current to turn on, so we limit the base current to less than 5mA with this resistor.
Pin 3 of the IC is the input of the circuit. The input should normally be held high. When you want to do a hardware reset of the Arduino, pull this pin low in your code. You can use any of the Arduino's analog or digital outputs for this.
Connect the collector of the transistor to the pin marked RESET on the Arduino.
Now the hardware is finished, and you need to program your Arduino to use this reset circuit. The code needed for this circuit is very simple.
7 - fixed steps 3 and 4
6 - fixed an error in the description
5 - fixed the text for the third step
4 - none
3 - changed name to indicate this project is built on a breadboard
2 - updated description
1 - Initial project release
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