hi,
i need help, i am going to play with my ardiuno uno. can any one list the things that damage my port pin or oter hardware. i mean precaution i need to take when interface with other hardware.
The list is almost endless but the simplest ones are, never apply more than 5 volts or less than 0 volts for inputs.
For outputs always ensure that less than 40mA current is sourced or sunk.
Never connect outputs together.
...avoid
- heating for too long when soldering,
- ESD or lightning strikes
- lump hammers.
so it means
as output port pin
1-we connect resistance to prevent damage to led
2-we connect resistance to prevent port if we connect high current device.
as input port pin
1-we connect pull up or down to just stbilize pin to low or high
please tell me is this correct
Hi, That list sounds right..
One approach to safety is to connect a resistor (220 ohms would be good) in series with the Arduino pins you are going to experiment with.
Then, from that resistor:
- You can connect an LED to either 5V or Ground (You have to have the correct polarity for the LED to light).
- You can connect some switch or other component connected to 5V or Ground as an Input. (The 220 ohms is insignificant for input purposes).
A even more bulletproof approach is to use a Zener diode to limit applied voltages, and a "resettable fuse" for overcurrent protection. ruggedcircuits.com does it this way:
And they sell a version of Arduino with this protection: http://ruggedcircuits.com/html/ruggeduino.html
DISCLAIMER: Hey I didn't mention ANYTHING from my own shop... 