Add startup and watchdog modules

README.md

@@ -2,10 +2,39 @@
 
 Library using cmsis_os2.h functionality for RTOS projects.
 
+Modules are enabled via defines set in `sta/config.hpp` provided by the application.
 
 
 ## System events
 
-Enable via `STA_SYSTEM_EVENT_ENABLE` defined in `sta/config.hpp`.
+Enable: `STA_SYSTEM_EVENT_ENABLE`
 
-Requires setup of a `systemEvent` EventFlag in the project.
+Requirements:
+* EventFlag: `systemEvent`
+
+
+## Watchdog
+
+Watchdog task gets woken periodically (every `STA_WATCHDOG_TIMER_PERIOD` ticks) or via `sta::nofityWatchdog(uint32_t)` calls
+and calls `sta::watchdogEventHandler(void *, uint32_t)`. Applications *must* implement `sta::watchdogEventHandler(void *, uint32_t)`.
+
+
+Enable: `STA_WATCHDOG_ENABLE`
+
+Requirements:
+* Task: `watchdog`
+* Timer: `heartbeat`
+
+Configuration:
+* Heartbeat timer period: `STA_WATCHDOG_TIMER_PERIOD` (defaults to `1000`).
+
+
+## Startup task
+
+Startup task calls `sta::startupTaskExtras(void *)`, starts the watchdog timer if enabled and terminates the thread.
+`sta::startupTaskExtras(void *)` may be overridden by the application.
+
+Enable: `STA_STARTUP_TASK_ENABLE`
+
+Requirements:
+* Task: `startupTask` (alternative: call manually in freertos.c default task)