HITL fan test (#1330)

* hitl fan test

* enable cooldown on dos as well

* small cleanup

* get expected RPM from panda class

* fix

* overshoot test

* fix max RPM getting

* fix percentage

* revert cooldown fix

---------

Co-authored-by: Comma Device <device@comma.ai>
Co-authored-by: Adeeb Shihadeh <adeebshihadeh@gmail.com>

Jenkinsfile

@@ -83,7 +83,7 @@ pipeline {
             phone_steps("panda-dos", [
               ["build", "scons -j4"],
               ["flash", "cd tests/ && ./ci_reset_internal_hw.py"],
-              ["test", "cd tests/hitl && HW_TYPES=6 pytest --durations=0 [2-6]*.py -k 'not test_send_recv'"],
+              ["test", "cd tests/hitl && HW_TYPES=6 pytest --durations=0 [2-7]*.py -k 'not test_send_recv'"],
             ])
           }
         }

tests/hitl/7_embedded.py

@@ -0,0 +1,42 @@
+import time
+import pytest
+
+from panda import Panda
+
+@pytest.mark.test_panda_types(Panda.INTERNAL_DEVICES)
+def test_fan_controller(p):
+  for power in [50, 100]:
+    p.set_fan_power(power)
+    time.sleep(10)
+
+    expected_rpm = Panda.MAX_FAN_RPMs[bytes(p.get_type())] * power / 100
+    assert 0.95 * expected_rpm <= p.get_fan_rpm() <= 1.05 * expected_rpm
+
+@pytest.mark.test_panda_types(Panda.INTERNAL_DEVICES)
+def test_fan_cooldown(p):
+  # if the fan cooldown doesn't work, we get high frequency noise on the tach line 
+  # while the rotor spins down. this makes sure it never goes beyond the expected max RPM
+  p.set_fan_power(100)
+  time.sleep(3)
+  p.set_fan_power(0)
+  for _ in range(5):
+    assert p.get_fan_rpm() <= 7000
+    time.sleep(0.5)
+
+@pytest.mark.test_panda_types(Panda.INTERNAL_DEVICES)
+def test_fan_overshoot(p):
+  # make sure it's stopped completely
+  p.set_fan_power(0)
+  while p.get_fan_rpm() > 100:
+    time.sleep(0.1)
+
+  # set it to 30% power to mimic going onroad
+  p.set_fan_power(30)
+  max_rpm = 0
+  for _ in range(50):
+    max_rpm = max(max_rpm, p.get_fan_rpm())
+    time.sleep(0.1)
+
+  # tolerate 10% overshoot
+  expected_rpm = Panda.MAX_FAN_RPMs[bytes(p.get_type())] * 30 / 100
+  assert max_rpm <= 1.1 * expected_rpm, f"Fan overshoot: {(max_rpm / expected_rpm * 100) - 100:.1f}%"