Initial public release of WII5 Buoy firmware

Firmware for an autonomous wave-measurement buoy (ATmega2560-based
WII5 v2 board). Reads wave motion from a Sparton AHRS-M1/M2 IMU,
samples GPS and battery state, and reports back over Iridium SBD
satellite telemetry. Originally developed 2012-2024.

This is the first public release. Code, documentation, and field-tested
operating modes (Capture, Sleep, Position, ManualTest, SelfTest,
LowBattery) are licensed under Apache 2.0 — see LICENSE and NOTICE.

See README.md for an overview and build instructions, CONTRIBUTING.md
for how to contribute, and DEPLOYMENTS.md for the field-deployment log.

WII5_board.h

@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright (c) 2012-2024 Scott Penrose <scottp@dd.com.au> and WII5 Buoy contributors
+//
+// This file is part of WII5 Buoy firmware.
+// See LICENSE for full terms.
+
+/**
+ * @file WII5_board.h
+ * @brief Board-selection shim: forwards to the active board's pin/peripheral header.
+ */
+
+/*
+
+WII5 Board File !
+
+This is included in all other files. In here we can change which board
+file we load. As much as possible this should be automatic, to allow switching
+between boards easily.
+
+*/
+
+// LOCAL - What is this?
+#define WII5_DEVICE_TYPE "WII5WaveBuoy"
+#define WII5_DEVICE_SUBTYPE "PiperC"
+#define WII5_SOFTWARE_NAME "WII5_Buoy"
+
+// Defaults - change these at build
+#ifndef WII5_SOFTWARE_VERSION
+#define WII5_SOFTWARE_VERSION "WII5Buoy_5.5.12"
+#endif
+#ifndef WII5_SOFTWARE_COMMIT
+#define WII5_SOFTWARE_COMMIT "Unknown"
+#endif
+#ifndef WII5_SOFTWARE_INTVER
+// a * 65536 + b * 256 + c
+//  5 * 65536 + 5 * 256 + 4 = 327680 + 1280 + 4 = 328964
+#define WII5_SOFTWARE_INTVER 328972
+#endif
+
+// 2019-05 - First board build for WII5
+// Currently only the WII5 v2 board is supported. Earlier prototypes (v1,
+// Arduino Mega devboard, Moteino Mega, M5Stick C) lived in this tree but
+// have been retired; see git history for those headers.
+
+#if defined (__WII5_V02__)
+#include <WII5_board_v2.h>
+#else
+#error "WII5 BOARD SELECTION = No board definition (expected __WII5_V02__)"
+#endif