QTR-8 Reflectance Sensor Array User's Guide

6. Breaking into Two Submodules
If you don’t need or cannot fit all eight sensors, the QTR-8x arrays can each be separated into two smaller sensor
arrays that can function independently: a two-sensor array and a six-sensor array.
To break the board, use a sharp knife (e.g. hobby knife or box cutter) to score along the perforation (row of vias)
between sensors 6 and 7. Place the long side of board on a flat surface with an edge, such as a table, so the
perforation lines up with the edge. Hold the board against the table and press firmly down on the overhanging piece
until it snaps off. If it doesn’t feel like the PC board is breaking, make the score deeper. You might want to file the
broken edges of the boards.
Once the board is broken, you will need to modify the small piece slightly before it becomes functional. If you are
operating at a Vcc of 5 V, solder the 100 Ohm through-hole resistor that was included with your QTR-8x across the
two pins as shown below:
If you are operating at a Vcc of 3.3 V, short those two pins together with a piece of wire. With a connection in place
between these two pins, the two-sensor board will function.
After the separation, sensor outputs 7 and 8 on the six-sensor board will no longer provide any signals.
QTR-8A and QTR-8RC Reflectance Sensor Array User's Guide © 2001–2009 Pololu Corporation
6. Breaking into Two Submodules Page 8 of 9