Throttle back, only run a 10 ms loop during PD negotiation, otherwise run the loop once / second.

Author: aentinger

src/Braccio++.cpp

@@ -95,12 +95,13 @@ bool BraccioClass::begin(voidFuncPtr custom_menu)
   Serial.begin(115200);
 
   pinMode(PIN_FUSB302_INT, INPUT_PULLUP);
+  attachInterrupt(PIN_FUSB302_INT, braccio_onPowerIrqEvent, FALLING);
   pinMode(RS485_RX_PIN, INPUT_PULLUP);
 
   _PD_UFP.init_PPS(_i2c_mtx, PPS_V(7.2), PPS_A(2.0));
-  attachInterrupt(PIN_FUSB302_INT, braccio_onPowerIrqEvent, FALLING);
-  _pd_thd.start(mbed::callback(this, &BraccioClass::pd_thread_func));
   _pd_timer.attach(braccio_onPowerTimerEvent, 10ms);
+  braccio_onPowerIrqEvent(); /* Start power burst. */
+  _pd_thd.start(mbed::callback(this, &BraccioClass::pd_thread_func));
 
   button_init();
 
@@ -118,7 +119,7 @@ bool BraccioClass::begin(voidFuncPtr custom_menu)
     lvgl_pleaseConnectPower();
 
   /* Loop forever, if no power is attached. */
-  while(!_PD_UFP.is_PPS_ready()) { }
+  while(!_PD_UFP.is_PPS_ready()) { delay(10); }
   lv_obj_clean(lv_scr_act());
 
   if (custom_menu)
@@ -438,30 +439,39 @@ void BraccioClass::lvgl_defaultMenu()
 void BraccioClass::pd_thread_func()
 {
   size_t last_time_ask_pps = 0;
+  unsigned long start_pd_burst = 0;
+  static unsigned long const START_PD_BURST_TIMEOUT_ms = 1000;
 
   for(;;)
   {
+    /* Wait for either a timer or a IRQ event. */
     uint32_t const flags = _pd_events.wait_any(0xFF);
 
-    if (flags & PD_IRQ_EVENT_FLAG)
+    /* The actual calls to the PD library. */
+    if ((millis() - last_time_ask_pps) > 5000)
     {
-      _pd_timer.detach();
-      _pd_timer.attach(braccio_onPowerTimerEvent, 10ms);
+      start_pd_burst = millis();
+      _PD_UFP.set_PPS(PPS_V(7.2), PPS_A(2.0));
+      last_time_ask_pps = millis();
     }
+    _PD_UFP.run();
+    _PD_UFP.print_status(Serial);
 
-    if (flags & PD_TIMER_EVENT_FLAG)
+    /* Set up the next time this loop is called. */
+    if (flags & PD_IRQ_EVENT_FLAG)
     {
+      start_pd_burst = millis();
       _pd_timer.detach();
       _pd_timer.attach(braccio_onPowerTimerEvent, 10ms);
     }
 
-    _PD_UFP.run();
-    _PD_UFP.print_status(Serial);
-
-    if ((millis() - last_time_ask_pps) > 5000)
+    if (flags & PD_TIMER_EVENT_FLAG)
     {
-      _PD_UFP.set_PPS(PPS_V(7.2), PPS_A(2.0));
-      last_time_ask_pps = millis();
+      _pd_timer.detach();
+      if ((millis() - start_pd_burst) < START_PD_BURST_TIMEOUT_ms)
+        _pd_timer.attach(braccio_onPowerTimerEvent, 10ms);
+      else
+        _pd_timer.attach(braccio_onPowerTimerEvent, 1000ms);
     }
   }
 }