added custom test code

test.py

@@ -0,0 +1,34 @@
+import subprocess
+import time
+import matplotlib.pyplot as plt
+
+ITERATIONS = 300
+ITERATION_DURATION = 1 #second(s)
+
+def set_rt_priority():
+   subprocess.run(["schedtool", "-F", "-p", "99"], check=True)
+
+def rt_task():
+    new_time = time.time()
+    jitter_record = []
+    for i in range(ITERATIONS + 1):
+        old_time = new_time
+        new_time = time.time()
+        print("--------------------------------------------------")
+        print(f"system time:\t{new_time} s")
+        print(f"time diff:\t{new_time - old_time} s")
+        jitter = new_time - old_time - ITERATION_DURATION
+        jitter_record.append(jitter)
+        print(f"jitter:\t{jitter} s")
+        time.sleep(new_time + ITERATION_DURATION - time.time())
+    jitter_record.pop(0)
+    plt.plot(jitter_record)
+    plt.title(f"Jitter at {ITERATION_DURATION} s interval")
+    plt.xlabel("Iteration")
+    plt.ylabel("Jitter (in s)")
+    plt.savefig("out.svg")
+
+
+if __name__ == "__main__":
+    set_rt_priority()
+    rt_task()