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.

tools/icsp.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+# 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.
+
+# Burn application + bootloader to an ATmega2560 over an ICSP programmer
+# (e.g. AVRISP mkII / Atmel STK500v2).
+#
+# Configure these env vars:
+: "${WII5_AVRDUDE:?path to avrdude binary}"
+: "${WII5_AVRDUDE_CONF:?path to avrdude.conf}"
+: "${WII5_FULL_HEX:?path to wii5_buoy.ino.hex}"
+: "${WII5_BOOT_HEX:?path to optiboot bootloader hex}"
+
+"$WII5_AVRDUDE" \
+	-C"$WII5_AVRDUDE_CONF" -v \
+	-patmega2560 \
+	-cstk500v2 \
+	-Pusb \
+	-D \
+	-Uflash:w:"$WII5_FULL_HEX" \
+	-Uboot:w:"$WII5_BOOT_HEX" \
+	-Ulock:w:0x0F:m
+
+# Notes:
+#   To set fuses on a fresh chip:
+#     avrdude ... -e -Ulock:w:0x3F:m -Uefuse:w:0xFD:m -Uhfuse:w:0xd6:m -Ulfuse:w:0xf7:m
+#   Then to flash bootloader + app, run this script.