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Old 07-14-2009, 12:29 PM   #2004 (permalink)
MPaulHolmes
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Quote:
Originally Posted by squiggles View Post
Actually this is not guaranteed. The ATmega8 output when low can be as high as 0.7V.
Hey Squiggles!

On pg. 265 of the ATMega8 datasheet, it has a graph called:

Figure 149. I/O Pin Sink Current vs. Output Voltage (VCC = 5V)

The current will be 5v / 10K for the pulldown, plus 5v / 1K for the PWM series resistor. That makes 5.5mA, which makes for approximately 0.2v. 0.2v + 0.7v is safely under for the HC74 family to be considered low. I see what you mean, though.



TheSGC: I need something that will run AVR Studio from Atmel, and that can function as a hyperterminal. I need to be able to get AVR Studio onto the computer, and I have one of those little plug things that go into the usb port. The older one I have doesn't have the right drivers to be able to read it. I think that's it.
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