Infrared Line Following Sensors

Infrared (IR) line following will be a new challenge at the Nebraska Robotics Expo for 2014. Participants will be offered electronic hardware to enable their CEENBoT to accept input from inexpensive IR line following sensors.

The sensors are tiny circuit boards with an infrared LED and an infrared receiver. The LED illuminates a small area beneath the board, and infrared light reflected back to the receiver produces a voltage that can be measured by the CEENBoT on an analog input. Each sensor comes with 3 solder points on board and a straight and right-angle header for use with an extender cable.

IR Line Following Robot.jpg

To make connection of the IR line following sensor to the robot easier, an adapter board is also offered. The adapter board comes in two versions, both connect to the 20 pin header on the CEENBoT.

IO Adapter.jpg
IO Adapter

Older CEENBoTs use a male 20 pin header, and a female adapter board connects to it. Newer CEENBoTs have a female 20 pin header, and a male adapter board connects to it.

Older CEENBoT connector -->
20 pin adapter old.jpg

You need this:
IO Adapter - Old Connector.jpg
IO Adapter - Old Connector

Newer CEENBoT connector -->
20 pin Adapter new.jpg
You need this:
IO Adapter - New Connector.jpg
IO Adapter - New Connector

If you would like to experiment with IR line following sensors, they are available for purchase from two on-line vendors. Product information is given below. The sensors come without wires or connectors attached, so you will need to solder 3 wires or a 3 pin header to each of your sensors. The sensors need 3 connections, listed in the table below

Pin 1
Pin 2
Pin 3

IR Line Following Sensor Connections


Pololu sells the sensors in packages of 2, so you will only need one package for a robot.

The challenge also provides a cable to connect from the sensor to the IO adapter board. You can make your own or purchase a servo extender cable for each sensor (qty 2) at:


SparkFun sells the sensors individually. The challenge requires 2, so you will need to order a quantity of 2.

If you do not get a pair of cables from an online seller, you will need to fabricate cables to connect your sensor to the IO adapter board. Make sure you connect the power, ground and signal wires correctly at both the robot end AND the sensor end, or you may damage either or both.