Introduction: RF Sheep Tracker - Keep Your Sheep in Sight!

About: come visit me!

Too many lost sheeps in this world.

Here is the ultimate invention to keep your sheep in sight.

What's RF Sheep Tracker ?

It's a collar equipped to transmit a continuous signal so, when it's out of range, a buzzer alert sound is played on the receiver device.

But the collar can do more:

  1. sheep moving alert - when is detected a motion of the sheep, a fast buzzer sound is played on receiver device (when transmitter and receiver are in range)
  2. rainbow light during "night mode" - a button activate night mode on the collar. A RGB led color cycle glows, giving a note of colour to your white sheep
  3. moving light during "night mode" - a flashing white light on motion detection on the collar so you can visually track your sheep during the motion

no sheeps were harmed during the testing of the RF Sheep Collar

manufacturer quote


Described features are obtained using:

Arduino Nano

RF 433MHz transmitter

Arduino Uno

RF 433MHz receiver

Lilypad RGB led


An accelerometer read motion status and send the information to Arduino Nano that manage it and, via RF transmitter, send continuously motion status to a receiver device.

If receiver device get signal means that the collar is "in range" and it shows only a blinking led . When receiver doesn't get incoming signal, an incremental buzzer alert sound can be listened.

When transmitter and receiver are "in range", if the information sent by the collar is "motion", a short buzzer sound can be listened on receiver device.

A button pressing on collar activates the "night mode". This means that the collar RGB Led glows and show, successively, sequential RGB colors and, when detect motion, a white blinking led alert glows instead of colors.

As you can see the concept is similar to Disco Dog . Differences are:
Disco Dog communicate via Bluetooth, RF Sheep Tracker via 433Mhz. This means more communication range for open spaces. The prototype made allow communication between transmitter and receiver around MAX 40 meters at open air . The range can be also reduced .


Step 2: PARTS (only for Collar Module)

Arduino Nano

Telecontrolli RT40 RF transmitter

Lilypad WS2812

MMA8452 Sparkfun accelerometer

Resistors - 2x330Ohm / 1KOhm / 1.2KOhm / 5.6KOhm / 10KOhm

Ceramic capacitor 100nF

Electrolitic capacitor 100uF

NPN general-purpose transistors (BC847 or BC337)

9V battery+connector


Slide switch


2 x Female strip header (5 pins + 6 pins)

5x7 breadboard

To make the collar i've adopted :

felt strip



sewing needle


For the receiver device see my previous instructabes "Peggy"


Transmitter device consists of four sections:

  1. Battery
  2. Accelerometer module + pushbutton + slide switch
  3. Arduino nano
  4. transmitter module & Lilypad power output section

Battery is connected via a on/off switch to accelerometer module (section 2) that has also a pushbutton to activate the "night mode". From Arduino Nano starts several jumpers to connect the two modules. Transmitter module (section 4) has two tasks, to transmit RF signals and to send power and control signal to Lilypad RGB led.

Following are showed basic connections that takes no account of the resistors, capacitors and transistor. That's fully explained on Autodesk Circuit schematic.

RF transmitter section has 6 pin strip header (left side of the schematic):

positive output to Lilypad

negative output to Lilypad

+5V input from +5V Arduino output

GND from Arduino

RF signal to Arudino pin 3 (see yellow cable on left section of schematic)

Led signal to Arduino pin 5

Accelerometer sections has 5 pin strip header (right side of the schematic):

3.3V input from 3.3V Arduino output

GND from Arduino GND

Accelerometer SDA to Arduino pin A4

Accelerometer SCL to Arduino pin A5

Pushbutton to Arduino pin D2

9V output to Arduino VIN pin

Battery positive cable goes through the slide switch, negative is connected to common ground.


I've adopted a fel stript: thickness 0.6 cm, width 5cm and lenght 45 cm. With the cutter create 4 hollows to fit all. At the end, after testing, you can sew Lilypad to three cables directed to the transmitter section.

Peel the cables and make a knot near peeled section. Insert in the eye of needle then pierce the felt. Once you have three contact on collar external side, you can solder Lilypad pinout without burning problems if you use felt.

The antenna (15.5cm copper cable) has been sewed inside the felt, then soldered to RF module antenna pinout.

At the end i suggest you to fasten the collar using velcro.

To facilitate modules fitting inside felt, a flexible plastic cylinder for each hollow could helps.

Step 5: SKETCH

Transmitter script adopt Virtual Wire library to send data to receiver. At power on, transmission starts. There are two kind of data transmitted: "STOP" and "MOVE". It depends by acceleration status. If acceleration is too much sensible, increase variable :

float AccSens=1.2;

Also, if you want to reduce transmission range, increase transmission speed in setup according with Virtual Wire library specs (set on receiver device same transmission speed).


Transmitter libraries: VirtualWire, Adafruit_NeoPixel, Wire, SparkFun_MMA8452Q.

Receiver script is a little bit different as showed on my previous instructables.

Only VirtualWire library needed

It detects STOP and MOVE status and activate accordingly buzzer signal.

Change "out of range" time into receiver sketch if it seems too short.

if(justnow>=counter+5000 && justnow<counter+10000)countButton=1; //after 5 secs of "out of range"


What else to say, this is the perfect Christmas gift for your sheep.... and for your peace of mind.


At this moment, since i don't own a sheep, the collar has been tested on Millie, my sister's dog.


Make it Glow Contest 2016

Participated in the
Make it Glow Contest 2016

Arduino Contest 2016

Participated in the
Arduino Contest 2016

Epilog Contest 8

Participated in the
Epilog Contest 8