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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|
Connect the 0.1uF capacitor between pin 6 of the IC and the ground rail. This capacitor determines how long the reset line is held low after the reset signal is received from the Arduino. Higher capacitor values make the output reset signal stay low longer.
Connect pin 6 of the IC to pin 7. I used a small jumper wire for this.
Put a 100k resistor between pin 7 of the IC and the +5V rail. Note that the board is rotated 180 degrees in this picture. This resistor determines how long the output reset pulse is (along with capacitor C1). Higher values of R1 make the output pulse longer.
Put a 10k resistor between pin 2 of the IC and the +5V rail. This resistor is used to pull up the input to the IC so that the RESET pin is normally held high even when there is no input to the reset circuit. This avoids accidental resets.
Insert the transistor like this. I prefer to put the collector of the transistor towards the top of the breadboard so it looks like the schematic. This transistor is used to invert the output of the 555 timer so that the output is active low instead of active high. The reset pin on the Arduino expects to be pulled low to initiate a reset. (You can use almost any transistor for this as long as it is NPN.)
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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