SparkFun Robotic Arm Clock with Ethernet Shield

July 17, 2013
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After I learned how to code the Arduino and work with the SparkFun claw, I wanted to build something that could be useful, stay out of the way, and always be running. I settled on a clock. To incorporate the robotic arm in to the clock I set the arm up to move like a minute hand. I can roughly tell what minute it is based on the location of the arm. In addition to the motion, the clock also plays a chime every hour. To find out what the temperature is I added a temperature sensor and LCD to display the temperature, time, and date. The date and time is loaded by the ethernet shield over NTP (Network Time Protocol). The ethernet shield also makes it possible to run a web page. The web page that is running allows the robotic arm to be controlled over the internet. The current setup allows me to fully utilize the functionality of the robotic arm and ethernet shield.

Full Clock

 Arm Mounting

To mount the robot arm to the wooden box I used erector set parts.

Inside the Box

With all the electrical parts inside the wooden box it can warm up. I do not trust the temperature sensor that is mounted on the breadboard.  I have plans of purchasing a better temperature sensor and mounting it on the outside of the box to get a better reading.


SparkFun Robotic Arm Clock_bb

The LCD required so many pins I had to add in a shift register. Obviously, the speaker was needed to play the chime. The pot is used as a dimmer for the LCD. The three servos are used in the arm. I found an old wall charger to get the needed 6v 2.0A for the servos. The arduino is powered with a 5v wall charger. So the clock requires two wall chargers. For the NTP and ethernet shield an ethernet wire is required.


This was written on Windows 7 with the Arduino 1.0.3 IDE. In order for the code to work you have to install extra libraries such as Time and LiquidCrystal_SR. Due to the html in the code, I don’t have it as part of the post. You can download it here:


The clock has two modes, clock mode and web mode. When the clock is in clock mode it acts like a clock with the arm moving every minute and a chime every hour. When the clock is in web mode the arm moves based on what links on the web site are clicked. The LCD is updated to show web mode. If no links are clicked on the web site after 30 seconds, the clock returns to clock mode.


Parts List


Arduino Uno R3 – $30

Arduino Ethernet Shield – $46

Sparkfun Robotic Claw – $12

Sparkfun Robotic Claw Pan/Tilt Bracket – $30

Miscellaneous Erector Set pieces

Breadboard – $5

2 Medium/Standard Servos – $12/ each

Small Speaker – $4

Temperature Sensor – $2

Potentiometer – $1

Shift Register IC 74HC595 – $1.50

From Amazon:

LCD Module for Arduino 20 x 4, White on Blue – $12

From the junk pile:

6V 2A power for servos

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