It is a pretty common first project to use an Arduino (or similar) to blink an LED. Which ... light that only works in the dark. A simple circuit, but it just goes to show that we tend to forget ...

The below circuit diagram shows the complete hardware wiring setup of the Arduino-based Smart Walking Stick for the Blind ...

We don’t really need most of the components on top of the chip (especially the status LED on the SCK line ... That one is a full Arduino, but the circuit board has no substrate.