The Soft Power Switch The Mk2 is a hard-on/hard-off, passive switch that has control and feedback from software. To put it another way, it functions similarly to a laptop's on/off switch. The system can be activated with a single press. The system can be turned off with another press (with MCU intervention). Additionally, holding down the button for about ten seconds will force a power-down if something goes really wrong. This board is essential if you're building something that requires a good power button and an enclosed battery. Although the Mk1 Soft Power Switch is excellent, we do occasionally encounter problems brought on by operating temperature or component tolerances. Mk2 is entirely digital and is based on an application note from Texas Instruments. It is centered on a