4.3 Connection for RESET

The RESET pin on the device is active-low, and setting the pin low externally will result in a Reset of the device.

AVR devices feature an internal pull-up resistor on the RESET pin, and an external pull-up resistor is normally not required.

The following figure shows the recommendation for connecting an external Reset switch to the device.

Figure 4-2. Recommended External Reset Circuit Schematic

A resistor in series with the switch can safely discharge the filtering capacitor. This prevents a current surge when shorting the filtering capacitor, which again can cause a noise spike that can harm the system.