Not exactly schematics, but [Duckman] has some Arduino pinout diagrams he made using ASCII-art. These could be useful when pasted into source code as comments, documenting the pinouts for your ...

Scheduled to appear in late May, Uno R4 will come in two versions: the plain ‘Uno R4 Minima’, and ‘Uno R4 WiFi’ with an Espressif S3 WiFi module that also gives it Bluetooth Low Energy. “We ...