Diff: tools/host_tests/wait_us_auto.py

Revision:

0:f269e3021894

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/host_tests/wait_us_auto.py	Sun Oct 23 15:10:02 2016 +0000
@@ -0,0 +1,69 @@
+"""
+mbed SDK
+Copyright (c) 2011-2013 ARM Limited
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+
+from time import time
+
+class WaitusTest():
+    """ This test is reading single characters from stdio
+        and measures time between their occurrences.
+    """
+    TICK_LOOP_COUNTER = 13
+    TICK_LOOP_SUCCESSFUL_COUNTS = 10
+    DEVIATION = 0.10    # +/-10%
+
+    def test(self, selftest):
+        test_result = True
+        # First character to start test (to know after reset when test starts)
+        if selftest.mbed.set_serial_timeout(None) is None:
+            return selftest.RESULT_IO_SERIAL
+        c = selftest.mbed.serial_read(1)
+        if c is None:
+            return selftest.RESULT_IO_SERIAL
+        if c == '$': # target will printout TargetID e.g.: $$$$1040e649d5c09a09a3f6bc568adef61375c6
+            #Read additional 39 bytes of TargetID
+            if selftest.mbed.serial_read(39) is None:
+                return selftest.RESULT_IO_SERIAL
+            c = selftest.mbed.serial_read(1) # Re-read first 'tick'
+            if c is None:
+                return selftest.RESULT_IO_SERIAL
+        start_serial_pool = time()
+        start = time()
+
+        success_counter = 0
+
+        for i in range(0, self.TICK_LOOP_COUNTER):
+            c = selftest.mbed.serial_read(1)
+            if c is None:
+                return selftest.RESULT_IO_SERIAL
+            delta = time() - start
+            deviation = abs(delta - 1)
+            # Round values
+            delta = round(delta, 2)
+            deviation = round(deviation, 2)
+            # Check if time measurements are in given range
+            deviation_ok = True if delta > 0 and deviation <= self.DEVIATION else False
+            success_counter = success_counter+1 if deviation_ok else 0
+            msg = "OK" if deviation_ok else "FAIL"
+            selftest.notify("%s in %.2f sec (%.2f) [%s]"% (c, delta, deviation, msg))
+            start = time()
+            if success_counter >= self.TICK_LOOP_SUCCESSFUL_COUNTS:
+                break
+        measurement_time = time() - start_serial_pool
+        selftest.notify("Consecutive OK timer reads: %d"% success_counter)
+        selftest.notify("Completed in %.2f sec" % (measurement_time))
+        test_result = True if success_counter >= self.TICK_LOOP_SUCCESSFUL_COUNTS else False
+        return selftest.RESULT_SUCCESS if test_result else selftest.RESULT_FAILURE