# Copyright (c) 2019 Foundries.io # Copyright (C) 2019 Peter Bigot Consulting, LLC # SPDX-License-Identifier: Apache-2.0 description: | GPIO pins exposed on Arduino Uno (R3) headers. The Arduino Uno layout provides four headers, two each along opposite edges of the board. Proceeding counter-clockwise: * An 8-pin Power Supply header. No pins on this header are exposed by this binding. * A 6-pin Analog Input header. This has analog input signals labeled from A0 at the top through A5 at the bottom. * An 8-pin header (opposite Analog Input). This has digital input signals labeled from D0 at the bottom D7 at the top; * A 10-pin header (opposite Power Supply). This has six additional digital input signals labelled from D8 at the bottom through D13 towards the top, skipping two pins, then finishing with D14 and D15 at the top. This binding provides a nexus mapping for 20 pins where parent pins 0 through 5 correspond to A0 through A5, and parent pins 6 through 21 correspond to D0 through D15, as depicted below: D15 21 D14 20 AREF - GND - - N/C D13 19 - IOREF D12 18 - RESET D11 17 - 3V3 D10 16 - 5V D9 15 - GND D8 14 - GND - VIN D7 13 D6 12 0 A0 D5 11 1 A1 D4 10 2 A2 D3 9 3 A3 D2 8 4 A4 D1 7 5 A5 D0 6 compatible: "arduino-header-r3" include: [gpio-nexus.yaml, base.yaml]