diff --git a/README.md b/README.md
index eda7793..bd7e059 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,13 @@ Navigate to http://localhost:8080/
 
 Matrix driver & Unicorn Hat HD driver inspired by https://github.com/vesteraas/node-unicornhathd
 
+### Unit tests
+This application has some unit tests, making use of [Jest](http://facebook.github.io/jest/). Jest is configured as a dev dependency.
+
+execute:
+
+    npm test
+
 ### Drawing
 ![Device drawing](https://raw.githubusercontent.com/sexybiggetje/pixdisp/screenshots/device.jpg "Drawing on the device")
 
diff --git a/__tests__/drawingoperations.js b/__tests__/drawingoperations.js
new file mode 100644
index 0000000..94f24d8
--- /dev/null
+++ b/__tests__/drawingoperations.js
@@ -0,0 +1,91 @@
+'use strict';
+
+let driver, config;
+
+let { DriverFactory } = require( '../drivers/driverfactory' );
+let { Dummy } = require( '../drivers/dummy' );
+
+let driverFactory = new DriverFactory();
+
+beforeEach(() => {
+	config = {
+		"driver": "dummy",
+		"matrix": {
+			"width": 4,
+			"height": 4,
+			"brightness": 1,
+			"flipHorizontal": false,
+			"flipVertical": false
+		}
+	};
+});
+
+test( 'Matrix creation', () => {
+	driver = driverFactory.createFromConfig( config );
+
+	expect( driver.getSize() ).toEqual( { width: 4, height: 4 } );
+	expect( driver.getBuffer().length ).toEqual( 48 );
+} );
+
+test( 'Set a pixel', () => {
+	driver = driverFactory.createFromConfig( config );
+
+	driver.setPixel( 0, 0, 255, 255, 255, 1 );
+	driver.setPixel( 3, 0, 255, 255, 255, 1 );
+	driver.setPixel( 0, 3, 255, 255, 255, 1 );
+	driver.setPixel( 3, 3, 255, 255, 255, 1 );
+
+	let matrix = driver.getMatrix();
+
+	expect( matrix[ 0 ][ 0 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+	expect( matrix[ 3 ][ 0 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+	expect( matrix[ 0 ][ 3 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+	expect( matrix[ 3 ][ 3 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+
+	expect( matrix[ 0 ][ 1 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+	expect( matrix[ 3 ][ 1 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+	expect( matrix[ 1 ][ 3 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+	expect( matrix[ 2 ][ 3 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+
+} );
+
+test( 'Draw a line', () => {
+	driver = driverFactory.createFromConfig( config );
+
+	driver.drawLine( 0, 0, 3, 3, 255, 255, 255, 1 );
+
+	let matrix = driver.getMatrix();
+
+	expect( matrix[ 0 ][ 0 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+	expect( matrix[ 1 ][ 1 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+	expect( matrix[ 2 ][ 2 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+	expect( matrix[ 3 ][ 3 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+
+	expect( matrix[ 0 ][ 1 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+	expect( matrix[ 1 ][ 2 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+	expect( matrix[ 2 ][ 3 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+	expect( matrix[ 3 ][ 0 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+
+} );
+
+test( 'Draw a circle', () => {
+	config.matrix.width = 8;
+	config.matrix.height = 8;
+
+	driver = driverFactory.createFromConfig( config );
+
+	driver.drawCircle( 3, 3, 4, 255, 255, 255, 1 );
+
+	let matrix = driver.getMatrix();
+
+	expect( matrix[ 1 ][ 0 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+	expect( matrix[ 2 ][ 0 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+	expect( matrix[ 2 ][ 6 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+	expect( matrix[ 3 ][ 6 ] ).toEqual( { r: 255, g: 255, b: 255, a: 1} );
+
+	expect( matrix[ 0 ][ 0 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+	expect( matrix[ 0 ][ 7 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+	expect( matrix[ 2 ][ 1 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+	expect( matrix[ 3 ][ 1 ] ).toEqual( { r: 0, g: 0, b: 0, a: 1} );
+
+} );
\ No newline at end of file
diff --git a/drivers/driver.js b/drivers/driver.js
index cad3b70..aa8b7f1 100644
--- a/drivers/driver.js
+++ b/drivers/driver.js
@@ -64,8 +64,8 @@ class Driver {
 	 * Set pixel color
 	 */
 	setPixel( x, y, r = 0, g = 0, b = 0, a = 1 ) {
-		if ( x >= 0 && x <= this.width &&
-			 y >= 0 && y <= this.height ) {
+		if ( x >= 0 && x < this.width &&
+			 y >= 0 && y < this.height ) {
 			this.matrix[x][y].r = r;
 			this.matrix[x][y].g = g;
 			this.matrix[x][y].b = b;
@@ -169,6 +169,13 @@ class Driver {
 		}
 	}
 
+	/**
+	 * Returns the current matrix at any given state
+	 */
+	getMatrix() {
+		return this.matrix;
+	}
+
 	/**
 	 * Get the buffer for writing
 	 * @return {Buffer}
diff --git a/package.json b/package.json
index c5f6416..9b479a7 100644
--- a/package.json
+++ b/package.json
@@ -18,6 +18,7 @@
   },
   "jest": {
     "name": "pixdisp",
-    "testRegex": "(/__tests__/.[^_]*|(\\.|/)(test|spec))\\.jsx?$"
+    "testRegex": "(/__tests__/.[^_]*|(\\.|/)(test|spec))\\.jsx?$",
+    "verbose": true
   }
 }