Add test for pin mode switching, analog read and write.

tests/test_pins.py

@@ -0,0 +1,87 @@
+#This tests that the mode of pins can be configured properly and that pull works OK.
+
+from microbit import *
+import music
+
+BIG_PINS = pin0, pin1, pin2
+DISPLAY_PINS = pin3, pin4, pin6, pin7, pin9, pin10
+
+def test_mode_switching():
+    print ("Switching mode from analog to digital on big pins")
+    for p0 in BIG_PINS:
+        p0.write_analog(100)
+        for p1 in BIG_PINS:
+            if p0 == p1:
+                try:
+                    p1.write_digital(0)
+                except ValueError:
+                    pass
+            else:
+                p1.write_digital(0)
+        p0.write_analog(0)
+
+def test_display_pins():
+    print ("Switching mode to digital for display pins")
+    for p0 in DISPLAY_PINS:
+        try:
+            p0.write_digital(0)
+        except ValueError:
+            pass
+    display.off()
+    for p0 in DISPLAY_PINS:
+        p0.write_digital(0)
+    display.on()
+    display.off()
+    for p0 in DISPLAY_PINS:
+        p0.write_analog(200)
+    try:
+        display.on()
+    except ValueError:
+        pass
+    for p0 in DISPLAY_PINS:
+        p0.write_analog(0)
+    display.on()
+
+def test_music():
+    print ("Switching mode to digital for music pins")
+    music.play(music.DADADADUM,pin=pin0,wait=False)
+    try:
+        pin0.write_digital(0)
+    except ValueError:
+        pass
+    music.stop()
+    pin0.write_digital(0)
+
+def test_pull():
+    print ("Setting pull on big pins")
+    for p in BIG_PINS:
+        p.set_pull(p.PULL_UP)
+        assert p.read_digital()
+        p.set_pull(p.PULL_DOWN)
+        assert p.read_digital() == 0
+    for p in BIG_PINS:
+        p.set_pull(p.PULL_UP)
+        assert p.read_analog() > 900
+        p.set_pull(p.NO_PULL)
+        assert 100 < p.read_analog() < 900
+        p.set_pull(p.PULL_DOWN)
+        assert p.read_analog() < 100
+    display.off()
+    for p in DISPLAY_PINS:
+        p.set_pull(p.PULL_UP)
+        assert p.read_digital()
+        p.set_pull(p.PULL_DOWN)
+        assert p.read_digital() == 0
+    display.on()
+
+try:
+    test_mode_switching()
+    test_display_pins()
+    test_music()
+    test_pull()
+    print("Pin test: PASS")
+    display.show(Image.HAPPY)
+except Exception as ae:
+    display.show(Image.SAD)
+    raise
+

tests/test_pwm.py

@@ -0,0 +1,37 @@
+#This tests that the duty cycle of PWM is (approximately) correct.
+
+from microbit import *
+
+def pins_connected(p0, p1):
+    for i in 0,1,0,1,0,1,0,1:
+        p0.write_digital(i)
+        if p1.read_digital() != i:
+            return False
+        p1.write_digital(i)
+        if p0.read_digital() != i:
+            return False
+    return True
+
+def test_pwm(p0, p1):
+    for val in 100, 200, 300, 500, 800, 900:
+        print("Testing duty cycle", val)
+        p0.write_analog(val)
+        sleep(1)
+        count = 0
+        for i in range(40*1024):
+            count += p1.read_digital()
+        # Allow +- 12.5%
+        assert abs(count - val*40) < val * 5
+
+try:
+    if pins_connected(pin0, pin1):
+        test_pwm(pin0, pin1)
+        print("PWM test: PASS")
+        display.show(Image.HAPPY)
+    else:
+        print("Connect pin0 to pin1")
+        display.show("?")
+except Exception as ae:
+    display.show(Image.SAD)
+    raise
+