Add UART receive interrupt handler

source/pyControl/hardware.py

@@ -287,9 +287,9 @@ class Analog_channel(IO_object):
 
     def __init__(self, name, sampling_rate, data_type, plot=True):
         assert data_type in ("b", "B", "h", "H", "i", "I"), "Invalid data_type."
-        assert not any(
-            [name == io.name for io in IO_dict.values() if isinstance(io, Analog_channel)]
-        ), "Analog signals must have unique names."
+        assert not any([name == io.name for io in IO_dict.values() if isinstance(io, Analog_channel)]), (
+            "Analog signals must have unique names."
+        )
         self.name = name
         assign_ID(self)
         self.sampling_rate = sampling_rate
@@ -348,9 +348,9 @@ class Analog_threshold(IO_object):
     # Generates framework events when an analog signal goes above or below specified threshold.
 
     def __init__(self, threshold=None, rising_event=None, falling_event=None):
-        assert isinstance(
-            threshold, int
-        ), "Integer threshold must be specified if rising or falling events are defined."
+        assert isinstance(threshold, int), (
+            "Integer threshold must be specified if rising or falling events are defined."
+        )
         self.threshold = threshold
         self.rising_event = rising_event
         self.falling_event = falling_event
@@ -509,3 +509,37 @@ def _timer_callback(self):
             fw.data_output_queue.put(fw.Datatuple(fw.current_time, fw.EVENT_TYP, "s", self.event_ID))
         self.state = not self.state
         self.sync_pin.value(self.state)
+
+
+class UART_handler(IO_object):
+    """
+    This class is used to generate a framework event when a UART message is received.
+    """
+
+    def __init__(self, event_name, first_char_interrupt=True):
+        self.event_name = event_name
+        self.last_interrupt_time = 0
+        self.first_char_interrupt = first_char_interrupt
+        if self.first_char_interrupt:
+            self.msg_starting = False
+        assign_ID(self)
+
+    def _initialise(self):
+        self.event_ID = sm.events[self.event_name] if self.event_name in sm.events else False
+
+    def ISR(self, _):
+        if self.event_ID:
+            # - pyboard v1.1 (and other STM32F4 boards): IRQ_RXIDLE interrupt is triggered after the first character
+            #   AND at the end when the RX is idle.
+            # - pyboard D-series board (STM32F7): IRQ_RXIDLE interrupt is triggered ONLY at the end when the RX is idle
+            # - see Micropytyhon UART docs for more info: https://docs.micropython.org/en/latest/library/machine.UART.html
+            if self.first_char_interrupt:
+                self.msg_starting = not self.msg_starting
+                if self.msg_starting:
+                    # ignore the first interrupt after the message starts (when using pyboard v1.1)
+                    return
+            self.timestamp = fw.current_time
+            interrupt_queue.put(self.ID)
+
+    def _process_interrupt(self):
+        fw.event_queue.put(fw.Datatuple(self.timestamp, fw.EVENT_TYP, "i", self.event_ID))