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I am learning about interrupts and one of the interrupt modes is LOW which triggers anytime the pin is a digital low.
Can someone tell me what voltage that is for an Arduino nano? I did a google search and it said a LOW can be anywhere from 0 to 2V.
I am making a project using a nano and I am powering it with batteries. It would be great if I could set up an interrupt to turn on an LED when the batteries were getting weak so I would know when to change them.
It would be great if I could set up an interrupt to turn on an LED when the batteries were getting weak
That won't work. The thresholds for the pin registering LOW or HIGH depend on the supply voltage. Very roughly:
For the exact voltage levels, you should check the datasheet.
Note also that those are guaranteed levels. The actual thresholds are closer to ½ Vcc, with an hysteresis of roughly Vcc/10.
For detecting a low battery condition, you should use the ADC, combined with either a voltage divider on Vcc or the internal bandgap reference.
triggers anytime the pin is a digital low... this is bad thinking ... it should betriggers anytime the pin transitions from high to low... there is a vast difference between the two