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Is there a way to destroy a microcontroller pin?
With a typical internal resistance of only 25 ohms per pin, a dead short to ground can allow as much as 200mA of current to flow, more than enough to destroy the microcontroller pin. The Ruggeduino protects against this destruction by putting a 30mA resettable fuse (PTC) in series with every I/O pin.
What causes a microcontroller to register a low or high?
The microcontroller may register a low, but it might just as well register a high. By not being connect to a source, Vcc, or GND, the I/O pin is susceptible to electrical noise that makes the I/O randomly fluctuate between low and high.
What to do if your micro-controller does not have serial port?
If you are using multiple micro-controllers and they do not have unique ids (common on boards with a CH340 USB chip) then follow the directions above using the command ls /dev/serial/by-path/* instead. Follow the directions in the “ Where’s my serial port? ” section to prevent this from occurring.
What to do if there are not enough pins on your Arduino?
There are a number of common solutions to “not enough pins”. Reduce the number of pins you need. This option is often discarded out of hand, but may be the best.
What is the maximum current that a microcontroller can withstand?
The microcontroller datasheet specifies an absolute maximum per-pin current of 40mA. With a typical internal resistance of only 25 ohms per pin, a dead short to ground can allow as much as 200mA of current to flow, more than enough to destroy the microcontroller pin.
How does PTC fuse work on Arduino microcontroller?
Now, instead of current flowing through the microcontroller’s internal protection diode, it flows safely through the zener diode, to ground, and back to the source of the overvoltage. The PTC fuse limits this current to 30mA so the 5.1V zener diode does not dissipate excessive power.