1 files changed, 108 insertions, 0 deletions
diff --git a/script/cat.py b/script/cat.py
new file mode 100755
index 0000000..330669e
--- /dev/null
+++ b/script/cat.py
@@ -0,0 +1,108 @@
+#!/usr/bin/env python3
+
+import re
+import serial
+import serial.threaded
+import sys
+import time
+
+cpu_freq = None
+timer_overflow = None
+
+
+class SerialReader(serial.threaded.Protocol):
+    """
+    Character- to line-wise data buffer for serial interfaces.
+
+    Reads in new data whenever it becomes available and exposes a line-based
+    interface to applications.
+    """
+
+    def __init__(self, callback):
+        """Create a new SerialReader object."""
+        self.callback = callback
+        self.recv_buf = ""
+
+    def __call__(self):
+        return self
+
+    def data_received(self, data):
+        """Append newly received serial data to the line buffer."""
+        try:
+            str_data = data.decode("UTF-8")
+            self.recv_buf += str_data
+
+            # We may get anything between \r\n, \n\r and simple \n newlines.
+            # We assume that \n is always present and use str.strip to remove leading/trailing \r symbols
+            # Note: Do not call str.strip on lines[-1]! Otherwise, lines may be mangled
+            lines = self.recv_buf.split("\n")
+            if len(lines) > 1:
+                self.recv_buf = lines[-1]
+                for line in lines[:-1]:
+                    self.callback(str.strip(line))
+
+        except UnicodeDecodeError:
+            pass
+            # sys.stderr.write('UART output contains garbage: {data}\n'.format(data = data))
+
+
+class SerialMonitor:
+    """SerialMonitor captures serial output for a specific amount of time."""
+
+    def __init__(self, port: str, baud: int, callback):
+        """
+        Create a new SerialMonitor connected to port at the specified baud rate.
+
+        Communication uses no parity, no flow control, and one stop bit.
+        Data collection starts immediately.
+        """
+        self.ser = serial.serial_for_url(port, do_not_open=True)
+        self.ser.baudrate = baud
+        self.ser.parity = "N"
+        self.ser.rtscts = False
+        self.ser.xonxoff = False
+
+        try:
+            self.ser.open()
+        except serial.SerialException as e:
+            sys.stderr.write(
+                "Could not open serial port {}: {}\n".format(self.ser.name, e)
+            )
+            sys.exit(1)
+
+        self.reader = SerialReader(callback=callback)
+        self.worker = serial.threaded.ReaderThread(self.ser, self.reader)
+        self.worker.start()
+
+    def close(self):
+        """Close serial connection."""
+        self.worker.stop()
+        self.ser.close()
+
+
+def handle_line(line):
+    if cpu_freq is not None:
+        print_line = line
+        for match in re.finditer("(\d+)/(\d+) cycles", line):
+            cycles = int(match.group(1))
+            overflows = int(match.group(2))
+            ms = (cycles + timer_overflow * overflows) * 1000 / cpu_freq
+            match_line = f"{cycles}/{overflows} cycles"
+            new_line = f"{ms} ms ({cycles}/{overflows} cycles)"
+            print_line = re.sub(match_line, new_line, print_line)
+        print(print_line)
+    else:
+        print(line)
+
+
+if __name__ == "__main__":
+    tty = sys.argv[1]
+    baud = int(sys.argv[2])
+
+    if len(sys.argv) > 4:
+        cpu_freq = int(sys.argv[3])
+        timer_overflow = int(sys.argv[4])
+
+    monitor = SerialMonitor(tty, baud, handle_line)
+    time.sleep(5)
+    monitor.close()