How Sensitive is the code Digitial Read? I would like voltage outputs required for an input to be defined as "HIGH"
Explain a bit more what you are needing.
toshib-htr:
How Sensitive is the code Digitial Read? I would like voltage outputs required for an input to be defined as "HIGH"
I wanted to know the same thing at one time so I took a pot and hooked up one end to the 5v and the other end to GND and fed the middle one to both a digital input pin and an analog one and when the the digital pin read high ( or low) I would read the analog value and send it out to the serial monitor.
There is some gap between the high and low.
Vin(high) ~= to .6 * Vcc...
RTFM... "Read That Fine Manual" / datasheet:http://www.atmel.com/images/atmel-8271-8-bit-avr-microcontroller-atmega48a-48pa-88a-88pa-168a-168pa-328-328p_datasheet.pdf..
Page 303
Symbol Parameter Condition Min. Typ. Max. Units
VIH Input High Voltage, except VCC = 1.8V - 2.4V 0.7VCC(2) VCC + 0.5 V
XTAL1 and RESET pins VCC = 2.4V - 5.5V 0.6VCC(2) VCC + 0.5 V
The chart in the book looks better but this is correct
Doc
Reply to #2... PAGE 303 of the data sheet... Vil = .2 - .3 * Vcc
Oops... So High = 3 - 3.5V @ 5V Vcc and Low = 1 - 1.5 V @ 5V Vcc Doc
What's the voltage required to register as HIGH for an input? Does it have to be 5 Volts or as little as 1 volt?
For a 5V Uno / Mega, 3.0V and above will read HIGH, 1.5V and below will read as LOW,
anything in the middle is undefined.