The ATtiny817 Xplained Mini has a default VCC of 5V. Many extension kits require 3.3V; in order to enable the boards to communicate effectively, they need to operate at the same voltage. It is possible to change the operating voltage on the Xplained Mini with only a few steps. Figure 1 shows the schematic for the power supply circuitry on the Xplained Mini. By removing the 0Ω resistor R100, and making the 3.3V connection outlined in Figure 2, the operating voltage will be changed from 5V to 3.3V.
Figure 1. ATtiny817 Xplained Mini Power
Supply Circuitry Schematic
Figure 2. ATtiny817 Xplained Mini Supply
Voltage Choices
