another attempt

Author: thomasjball

cpp/jddisplay.cpp

@@ -97,12 +97,13 @@ JDDisplay::JDDisplay(SPI *spi, Pin *cs, Pin *flow) : spi(spi), cs(cs), flow(flow
     flow->eventOn(DEVICE_PIN_EVT_RISE);
 
     // set up polling for buttons
-    EventModel::defaultEventBus->listen(DEVICE_ID_COMPONENT, DEVICE_COMPONENT_EVT_SYSTEM_TICK, this, &JDDisplay::pollButtons);
+    EventModel::defaultEventBus->listen(DEVICE_ID_COMPONENT, DEVICE_COMPONENT_EVT_SYSTEM_TICK, this, 
+                                        &JDDisplay::pollButtons, MESSAGE_BUS_LISTENER_IMMEDIATE);
 }
 
 void JDDisplay::pollButtons(Event) {
-    inProgressLock.wait();
-    step(false);
+    if (stepWaiting)
+        step(false);
 }
 
 void JDDisplay::sendDone(JDDisplay* jdd) {
@@ -261,7 +262,7 @@ void JDDisplay::step(bool sendImage) {
     }
 
     if (!sendImage) {
-        flushSend();
+        sendDone(this);
         return;   
     }