diff --git a/test/test.cpp b/test/test.cpp
index affab10..5ef18ac 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -1,6 +1,152 @@
 #include "Arduino.h"
 #include "ArduinoUnitTests.h"
+#include <PID_v1.h>
 
-unittest(test) { assertTrue(true); }
+unittest(direct) {
+
+  // Define Variables we'll be connecting to
+  double Setpoint, Input, Output;
+
+  // Specify the links and initial tuning parameters
+  PID myPID(&Input, &Output, &Setpoint, 2, 5, 1, DIRECT);
+
+  // initialize the variables we're linked to
+  Input = 50;
+  Setpoint = 100;
+
+  // turn the PID on
+  myPID.SetMode(AUTOMATIC);
+  for (int i = 0; i < 1000; i++) {
+    delay(200);
+    if (myPID.Compute()) {
+      Input = Input + (Output - Input) / 25.6;
+    }
+  }
+  // std::cout << "Input = " << Input << "; Output = " << Output << std::endl;
+  assertEqual(Setpoint, round(Input));
+}
+
+unittest(reverse) {
+
+  // Define Variables we'll be connecting to
+  double Setpoint, Input, Output;
+
+  // Specify the links and initial tuning parameters
+  PID myPID(&Input, &Output, &Setpoint, 2, 5, 1, REVERSE);
+
+  // initialize the variables we're linked to
+  Input = 50;
+  Setpoint = 100;
+
+  // turn the PID on
+  myPID.SetMode(AUTOMATIC);
+  for (int i = 0; i < 1000; i++) {
+    delay(200);
+    if (myPID.Compute()) {
+      Input = Input + (Input - Output) / 25.6;
+    }
+  }
+  // std::cout << "Input = " << Input << "; Output = " << Output << std::endl;
+  assertEqual(Setpoint, round(Input));
+}
+
+unittest(mode) {
+
+  // Define Variables we'll be connecting to
+  double Setpoint, Input, Output;
+
+  // Specify the links and initial tuning parameters
+  PID myPID(&Input, &Output, &Setpoint, 2, 5, 1, REVERSE);
+
+  // initialize the variables we're linked to
+  Input = 50;
+  Setpoint = 100;
+
+  // turn the PID on
+  myPID.SetMode(MANUAL);
+  for (int i = 0; i < 1000; i++) {
+    delay(200);
+    if (myPID.Compute()) {
+      Input = Input + (Input - Output) / 25.6;
+    }
+  }
+  // std::cout << "Input = " << Input << "; Output = " << Output << std::endl;
+  assertEqual(50, round(Input));
+}
+
+unittest(getFunctions) {
+
+  // Define Variables we'll be connecting to
+  double Setpoint, Input, Output;
+
+  // Specify the links and initial tuning parameters
+  PID myPID(&Input, &Output, &Setpoint, 2, 5, 1, REVERSE);
+
+  // initialize the variables we're linked to
+  Input = 50;
+  Setpoint = 100;
+
+  // turn the PID on
+  myPID.SetMode(AUTOMATIC);
+
+  // std::cout << "Input = " << Input << "; Output = " << Output << std::endl;
+  assertEqual(2, myPID.GetKp());
+  assertEqual(5, myPID.GetKi());
+  assertEqual(1, myPID.GetKd());
+  assertEqual(REVERSE, myPID.GetDirection());
+  assertEqual(AUTOMATIC, myPID.GetMode());
+}
+
+unittest(sampleTimeWorks) {
+
+  // Define Variables we'll be connecting to
+  double Setpoint, Input, Output;
+
+  // Specify the links and initial tuning parameters
+  PID myPID(&Input, &Output, &Setpoint, 2, 5, 1, REVERSE);
+
+  // initialize the variables we're linked to
+  Input = 50;
+  Setpoint = 100;
+
+  bool flag = false;
+  // turn the PID on
+  myPID.SetMode(AUTOMATIC);
+  for (int i = 0; i < 1000; i++) {
+    delay(200);
+    if (myPID.Compute()) {
+      flag = true;
+      Input = Input + (Input - Output) / 25.6;
+    }
+  }
+  // std::cout << "Input = " << Input << "; Output = " << Output << std::endl;
+  assertTrue(flag);
+}
+
+unittest(sampleTimeNotWorks) {
+
+  // Define Variables we'll be connecting to
+  double Setpoint, Input, Output;
+
+  // Specify the links and initial tuning parameters
+  PID myPID(&Input, &Output, &Setpoint, 2, 5, 1, REVERSE);
+
+  // initialize the variables we're linked to
+  Input = 50;
+  Setpoint = 100;
+
+  bool flag = false;
+  // turn the PID on
+  myPID.SetMode(MANUAL);
+  for (int i = 0; i < 1000; i++) {
+    delay(199);
+    if (myPID.Compute()) {
+      flag = true;
+      Input = Input + (Input - Output) / 25.6;
+    }
+  }
+  // std::cout << "Input = " << Input << "; Output = " << Output << std::endl;
+  assertFalse(flag);
+}
 
 unittest_main()