4.5.2 Operation at Other Voltages

The ATtiny3217 Xplained Pro board is operated at 3.3V by default, but it can also operate from other voltages from an external supply. The EDBG is designed to run from a 3.3V supply and won't work on other voltages, therefore all connections from the EDBG and the on-board 3.3V regulator to the ATtiny3217 should be removed.

To completely disconnect the EDBG and the on-board power supply from the ATtiny3217, do the following:

  • Remove the two jumpers from the on-board 3-pin current measurement headers (J101 and J102), and connect the two center pins (pin 2) with a wire or an ammeter, as shown in Figure 4-7
  • Remove R404, R406, R407, R408, R414, R415, R416, R417, R420, R425, R426
  • Optionally, cut J100 to remove power to the on-board current measurement headers (J101 and J102) from the on-board regulator

Figure 4-6 shows all components that have to be removed from the bottom side of the PCB for operation at other voltages. To locate the other components, see the assembly drawing in the section above. The kit can be supplied with the desired voltage through the pins marked 3.3V (pin four) and GND (pin two) on the Xplained Pro power header when the components are removed. To program and debug the ATtiny3217, the 2x5 50mil UPDI debug connector has to be used with an external debugger.

Info: Operating the ATtiny3217 on other voltages than 3.3V requires physical modifications on the kit using a soldering iron and an external debugger for programming the ATtiny3217. The on-board current measurement only works at 3.3V. The on-board LED is selected for 3.3V operation. The light level at 1.8V operation is very low. To increase the emitted light level, the value of the series resistor can be lowered. The EDBG functionality can be restored by re-soldering the removed components. If J100 was cut, a 0Ω resistor can be soldered across the cut.
CAUTION: The voltage supplied through the power header is applied directly to the ATtiny3217 and the extension headers. Applying a voltage higher than 5.5V may damage the board permanently.
Figure 4-6. ATtiny3217 Xplained Pro EDBG Disconnect
Figure 4-7. ATtiny3217 Xplained Pro Current Measurement Headers