Example to build a trafficlight control with Raspberry Pi Pico and its PIO hardware.

Prerequisite: You have installed the PICO-SDK and all necessary tools for Raspberry Pi Pico on your system.

You may copy the directory structure to your own system and adapt the PDK-SDK-PATH to the CMake-files or set the enviroment variable PICO_SDK_PATH. Then within the PIO-Beispiel folder you may just call: cmake . && make

The Example Circuit assumes there is a white LED on GPIO17 ; can be left out, it just signals new red phase in the unoptimized version. ; in the optimized version it signals red and green phases

red LED on GPIO18

yellow LED on GPIO19

green LED on GPIO20

I am using 220 Ohm resistors for the LEDs

The Out-Mapping is defined as {GPIO17, GPIO18, GPIO19, GPIO20} The OSR (Output-Shift-Register stores the patterns for the phases red, red-yellow, green, yellow Its 4 bit shifts control the LEDs accordingly

In the PIO state machine the OSR conducts right shifts.