The idea is to build a cheap and modular security robot as a Do-it-Yourself project with a Raspberry Pi as the brain of the robot. The robot will inform you over internet if an intruder is detected in your home. The robot will take pictures and videos from the burglar. Depending on the internet connection and configuration everything can be uploaded to a cloud storage provider outside the house for security reasons. Depending on the configuration an e-mail with pictures will be send out by the security robot. Many different alert scenarios are conceivable.

With the two servo motors inside the robot a 360 degree round view is possible. The robot is able to take pictures from defined views and to check if something has changed in the picture like a broken window or a missing object. At the moment the robot is designed for indoor usage only. The concept is a stationary robot.

The picture below shows the first design idea of the robot and the sensors.

custom build security robot

custom build security robot

With the IR sensors and ultrasonic sensors a perfect motion detection is in place to support the camera. With the additional sensors the security is improved to a maximum. The four IR sensors are integrated into the body. For the ultrasonic sensors I am not sure how I will integrate them into the security robot body.

The picture below shows the security robot body open with the IR sensors.

custom build security robot - IR-sensors

custom build security robot – IR-sensors

Maybe the next version will be able to go on patrol in your home with some dc motors and wheels.

The main components are a Raspberry Pi Zero or Raspberry Pi 3. As sensors I am thinking about four HC-SR501 IR sensors and four HC-SR04 ultrasonic sensors for motion detection. The Raspberry Pi camera mounted on top of a pan & tilt kit enables the robot to monitor the room and to take pictures as a security camera. To detect fire I am thinking about some smoke detectors and air quality sensors in general.

custom build security robot open body

custom build security robot open body

The pictures taken by the camera should be stored in a cloud service to protect them for being deleted or stolen from an intruder.

The next step is to finish the case and to mount all sensors into the body of the robot. At the moment I am not sure if I will give the Zero a chance. The main problem is the missing CSI interface for the Raspberry Pi camera. On the other hand there is not much space for the Raspberry Pi, the servo motors and sensors.

The picture below shows the security robot body closed with the Pan&Tilt kit on top.

custom build security robot - IR-sensors and Pan&Tilt kit

custom build security robot – IR-sensors and Pan&Tilt kit

Raspberry Pi Zero – USB Hub

To connect the USB WIFI module and a USB Web-Cam I need a USB Hub. The Raspberry Pi Zero has only one USB connector. I bought two cheap mini USB Hubs from LogiLink each for 2.90 € in an online shop.

Then I opend one and checked how the USB cable is connected to the PCB board inside the hub. The picture below shows the open USB Hub and a new one.

custom build security robot - mini USB Hub

custom build security robot – mini USB Hub

A USB cable consist out of four wires (red, green, white and black). The next step was to remove the white USB cable from the mini USB Hub. Then I cut one micro USB cable in the middle. I need the micro USB plug to connect the cable to the Raspberry Pi Zero. Then I soldered the black cable directly to the USB Hub.

custom build security robot - mini USB Hub wires

custom build security robot – mini USB Hub wires

A few minutes later the black wire was soldered to the Mini USB Hub and the WIFI module, keyboard and mouse worked perfectly together with the Raspberry Pi Zero.

custom build security robot - mini USB Hub with mico USB cable

custom build security robot – mini USB Hub with mico USB cable

Now I need a camera for my security robot.

Hardware Update 2016-07-27

Today I had time to think about the hardware setup of my security robot. With the latest Raspberry Pi Zero I am able to connect via the micro CSI calbe the Raspberry Pi NoIR camera module version 2.1. But the micro CSI cable is very short. I am not sure if this short cable will work together with the servo motors and the pan & tilt functionality of my security robot. On the other hand I could use the usb web-cam I already tested together with the mjpg-stream and yeahhh it works perfect.

Security-robot hardware setup

Security-robot hardware setup

Security robot web interface

With the user interface implemented as a web interface it will be possible to configure and control the security robot remote. A user interface will be implemented to remote control the pan & tilt camera to move the camera around. This enables the user to monitor different parts of a room or area and to check manually the environment for suspicious objects. The live video stream will be transmitted over the internet. With the live view received by your smart phone or tablet while you are on vacation you are able to check your home if everything is fine.

Security camera

A security robot needs a camera to monitor and secure the environment. A static camera can only be used to monitor a single view or defined area. If you need to monitor not only one view you need a camera which is able to move around. With a pan & tilt kit the camera has a 360 degree view of the area in which the camera is installed. Pre defined movements of the security camera could be defined. The programmed and defined positions of the camera and triggered actions like taking pictures and uploading them into a cloud service will improve the security significant. As well a user interface will enable the user to manual control the camera movements. The interface will be implemented via a web site and corresponding web service.

The camera itself is able to monitor your pats and your are able to check there well being remotely during your absence.

Philips Hue integration

With a Philips Hue integration the security robot is able to control the lights in your home. The idea and plan is to automatically switch on the lights if a motion is detected. Or to control the lights automatically to simulate that someone is at home. This will additionally increase the security of your home. In combination with a light control an alarm function could be implemented to help you wake up. With the motion detection sensors the light could switched on to help you to find your way into the bathroom or kitchen.


To build a microphone into the security robot would be very nice. No idea how to get a sound card working but I will give it a try.

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