SparkFun Electronics will be closed in observance of memorial day on Monday, May 29th. We will resume normal business hours on Tuesday, May 30th. Any orders placed after 2pm Mountain Time on Friday, May 26th will process and ship out on Tuesday, May 30th.


Member Since: December 7, 2011

Country: United States

  • According to the ATmega328 datasheet, Vih is 0.6Vcc at Supply voltage of 5v.

    So Vih in my case is 3v.

    I’m probably not going to find a datasheet for an iPhone 3G (my 3.3v device) so i’ll just have to try it and find out!

    Thanks for your help :)

  • Why can’t I just use a simple resistive voltage divider with 1.5k + 3k in series, take the output across the 3k resistor to get 3.3v?

    That would be used on the TX line of the 5v device. Is it because the +3.3v on the other device’s TX isn’t a strong enough logic high for the +5v device’s RX?

No public wish lists :(