[testing] add PWM input test

tools/odrive/tests/pwm_input_test.py

@@ -0,0 +1,130 @@
+
+import test_runner
+
+import time
+import math
+import os
+
+import fibre
+from fibre.utils import Logger
+from odrive.enums import errors
+from test_runner import ODriveTestContext, test_assert_eq, program_teensy
+
+#def modpm(val, lower_bound, upper_bound):
+#    return ((val - lower_bound) % (upper_bound - lower_bound)) - lower_bound
+
+def modpm(val, range):
+    return ((val + (range / 2)) % range) - (range / 2)
+
+class TestPwmInput():
+    """
+    Verifies the PWM input.
+
+    The Teensy generates a PWM signal that goes from 0% (1ms high) to 100% (2ms high)
+    in 1 second and then resumes at 0%.
+
+    This test takes about 1min.
+
+    Note: this test is currently only written for ODrive 3.6 (or similar GPIO layout).
+    """
+
+    def is_compatible(self, odrive: ODriveTestContext):
+        return True
+
+    def run_delta_test(self, attr, with_min, with_max, timeout = 5.0):
+        rounds_per_s = 1.0
+        units_per_s = (with_max - with_min) * rounds_per_s
+        step_size = units_per_s * 0.02 # 20ms per step
+        min_val = math.inf
+        max_val = -math.inf
+        cumulative_delta = 0
+
+        rate = units_per_s
+        rate_gain = 1 / 0.5 # 200ms time constant
+
+        # Could do something fancy like fit a piecewise linear function
+
+        start = time.monotonic()
+        i = 0
+        while True:
+            now = time.monotonic()
+            new_val = attr.get_value()
+            min_val = min(min_val, new_val)
+            max_val = max(max_val, new_val)
+
+            if i > 0:
+                dt = now - before
+                delta = modpm(new_val - last_val, with_max - with_min)
+                cumulative_delta += delta
+
+                # low pass filter rate
+                rate += (delta / dt - rate) * min(rate_gain * dt, 1)
+                #print("rate", rate)
+            
+                # After 500ms verify the rate
+                if now - start > 0.5:
+                    # 40% seems like a very large range. With a smaller range
+                    # the test tends to fail. May want to investigate if this 
+                    # is only because of the non-realtimeness of the tester
+                    # of if it's an actual problem. Looks fine on software oscilloscope.
+                    test_assert_eq(rate, units_per_s, accuracy=0.4)
+ 
+            before = now
+            last_val = new_val
+ 
+            if (now - start > timeout):
+                break
+            time.sleep(0.005) # PWM time resolution is 20ms, so let's read a bit slower.
+            i += 1
+        
+        # Check the total incement during this time
+        test_assert_eq(cumulative_delta, timeout * units_per_s, accuracy=0.1)
+
+        # Check that the minimum and maximum values were observed
+        test_assert_eq(min_val, with_min, range = step_size)
+        test_assert_eq(max_val, with_max, range = step_size)
+
+    def run_test(self, odrive: ODriveTestContext, logger: Logger):
+        # TODO: test each GPIO separately
+        hexfile = 'pwm_sim.ino.hex'
+        program_teensy(os.path.join(os.path.dirname(__file__), hexfile), 26, logger)
+        time.sleep(1.0) # wait for PLLs to stabilize
+
+        logger.debug("Set up PWM input...")
+        odrive.handle.erase_configuration()
+        odrive.handle.config.enable_uart = False
+        odrive.handle.config.gpio1_pwm_mapping.endpoint = odrive.handle.axis0.controller._remote_attributes['input_pos']
+        odrive.handle.config.gpio1_pwm_mapping.min = -50
+        odrive.handle.config.gpio1_pwm_mapping.max = 200
+        odrive.handle.config.gpio2_pwm_mapping.endpoint = odrive.handle.axis1.controller._remote_attributes['input_pos']
+        odrive.handle.config.gpio2_pwm_mapping.min = 20
+        odrive.handle.config.gpio2_pwm_mapping.max = 400
+        odrive.handle.config.gpio3_pwm_mapping.endpoint = odrive.handle.axis0.controller._remote_attributes['input_vel']
+        odrive.handle.config.gpio3_pwm_mapping.min = -1000
+        odrive.handle.config.gpio3_pwm_mapping.max = 0
+        odrive.handle.config.gpio4_pwm_mapping.endpoint = odrive.handle.axis1.controller._remote_attributes['input_vel']
+        odrive.handle.config.gpio4_pwm_mapping.min = -20000
+        odrive.handle.config.gpio4_pwm_mapping.max = 20000
+        
+        # Save and reboot
+        odrive.handle.save_configuration()
+        try:
+            odrive.handle.reboot()
+        except fibre.ChannelBrokenException:
+            pass # this is expected
+        odrive.handle = None
+        time.sleep(2)
+        odrive.make_available(logger)
+
+        logger.debug("Check if PWM on GPIO1 works...")
+        self.run_delta_test(odrive.handle.axis0.controller._remote_attributes['input_pos'], -50, 200)
+        logger.debug("Check if PWM on GPIO2 works...")
+        self.run_delta_test(odrive.handle.axis1.controller._remote_attributes['input_pos'], 20, 400)
+        logger.debug("Check if PWM on GPIO3 works...")
+        self.run_delta_test(odrive.handle.axis0.controller._remote_attributes['input_vel'], -1000, 0)
+        logger.debug("Check if PWM on GPIO4 works...")
+        self.run_delta_test(odrive.handle.axis1.controller._remote_attributes['input_vel'], -20000, 20000)
+
+
+if __name__ == '__main__':
+    test_runner.run(TestPwmInput())

tools/odrive/tests/test_runner.py

@@ -144,6 +144,7 @@ def program_teensy(hex_file_path, program_gpio: int, logger: Logger):
     
         echo 26 | sudo tee /sys/class/gpio/export
         sudo chmod a+rw /sys/class/gpio/gpio26/*
+        echo out > /sys/class/gpio/gpio26/direction
 
     """