message: Sleep for a few seconds at startup.
  Due to a hardware issue, the blower always spins up when the board
  restarts.  Wait for the blower to spin down, otherwise the sensors will
  be miscalibrated.
  GPC: sleep-at-startup
diff: @@ -152,6 +152,16 @@ static void high_priority_task(void *arg) {
  // after some basic system init. Pretty much everything not time critical
  // should go here.
  static void background_loop() {
  + // Sleep for a few seconds. In the current iteration of the PCB, the fan
  + // briefly turns on when the device starts up. If we don't wait for the fan
  + // to spin down, the sensors will miscalibrate. This is a hardware issue
  + // that will be fixed in the PCB revision after 0.2.
  + // https://respiraworks.slack.com/archives/C011CJQV4Q7/p1591745893290300?thread_ts=1591745582.289600&cid=C011CJQV4Q7
  + Time sleepStart = Hal.now();
  + while (Hal.now() - sleepStart < seconds(10)) {
  + Hal.delay(milliseconds(10));
  + Hal.watchdog_handler();
  + }
  // Calibrate the sensors.
  // This needs to be done before the sensors are used.
  