diff --git a/.arduino-ci.yml b/.arduino-ci.yml
new file mode 100644
index 0000000..8a095a8
--- /dev/null
+++ b/.arduino-ci.yml
@@ -0,0 +1,25 @@
+# https://github.com/Arduino-CI/arduino_ci/issues/159
+# copied from vendor/bundle/ruby/2.6.0/gems/arduino_ci-0.3.0/misc/default.yml
+platforms:
+  mega2560:
+    board: arduino:avr:mega:cpu=atmega2560
+    package: arduino:avr
+    gcc:
+      features:
+      defines:
+        - __AVR_ATmega2560__
+        # added this line
+        - ARDUINO_CI
+      warnings:
+      flags:
+
+unittest:
+  platforms:
+    - mega2560
+  testfiles:
+    reject:
+      - "Common.cpp"
+
+compile:
+  platforms:
+    - mega2560
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..db7e8b5
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,6 @@
+.bundle
+Gemfile.lock
+vendor
+# C++ stuff
+*.bin
+*.bin.dSYM
diff --git a/Gemfile b/Gemfile
new file mode 100644
index 0000000..fb422d1
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,2 @@
+source 'https://rubygems.org'
+gem 'arduino_ci'
diff --git a/PID_v1.cpp b/src/PID_v1.cpp
similarity index 100%
rename from PID_v1.cpp
rename to src/PID_v1.cpp
diff --git a/PID_v1.h b/src/PID_v1.h
similarity index 100%
rename from PID_v1.h
rename to src/PID_v1.h
diff --git a/test/test.cpp b/test/test.cpp
new file mode 100644
index 0000000..5ef18ac
--- /dev/null
+++ b/test/test.cpp
@@ -0,0 +1,152 @@
+#include "Arduino.h"
+#include "ArduinoUnitTests.h"
+#include <PID_v1.h>
+
+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()