Encoder for Pololu Wheel 42x19mm

• Compatible with 42x19 mm wheel (not included)
• Encoder teeth built into hub
• Fits Pololu micro metal gearmotors, wheel and bracket
• Resolution of 48 counts per revolution

The Encoder for Pololu Wheel 42x19mm works with micro metal gearmotors, 42×19mm wheel and extended bracket to measure the rotation speed and direction of the wheel. With twelve teeth on the wheel, the system provides a resolution of 48 counts per revolution, which corresponds to a linear resolution of just less than 3 mm or 1/8".

This quadrature encoder board is designed to hold two infrared reflectance sensors inside the hub of a Pololu 42×19mm wheel and measure the movement of the twelve teeth along the wheel’s rim. The two sensors are spaced to provide waveforms approximately 90 degrees out of phase, allowing the direction of rotation to be determined and providing four counts per tooth for a resolution of 48 counts per wheel rotation. Each analog sensor signal is fed to a comparator with hysteresis to provide glitch-free digital outputs. The compact layout of the board fits all of the components within the envelope of the hub and tire, allowing the board to be mounted between the motor and a chassis. The encoder is calibrated for operation from 4.5 V to 5.5 V, but it can be recalibrated for operation at 3.3 V.

Features
• Operating voltage: 4.5 V to 5.5 V (encoder can be modified for lower voltages)
• Two digital outputs (quadrature)
• 14 mA current consumption at 5.0 V
• 48 counts per revolution (linear resolution of just under 3 mm or 1/8")
• Small size: fits between motor and chassis
• Weight: 1.6 g (0.06 oz)

Note: The wheel, motor, bracket, hub and Pololu 5" round robot chassis RRC04A are sold separately.