This quadrature encoder board is designed to hold two infrared reflectance sensors inside the hub of the 42x19mm 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 (see photo to the right).
The two outputs of the encoder are digital outputs that can be connected directly to digital input pins on most microcontrollers (inputs that can generate interrupts on change are recommended). With 48 state changes per revolution of the 42 mm wheel, a speed of 1 m/s (a bit over 3 feet per second) generates approximately 360 state changes per second. With two encoders used simultaneously, as is the case for most differential-drive robots, the encoders will require attention almost every millisecond. Decoding the encoder outputs should only take a few percent of the processing power of a microcontroller such as the Atmel ATMega168.
- 4.5V - 5.5V operating voltage
- 2 digital outputs
- 14mA consumption at 5V
- 48 counts per revolution (linear resolution just under 3mm)
- 2A continuous paralleled output current
- 100kHz maximum PWM frequency
- 2.7-5.5VDC logic voltage
This product is listed in:
Documentation and Resources:
- The Maker Revolution
The Maker Revolution celebrates the creation of new devices and the modification of existing ones - the transition from a consumer buying goods to eventually having a major part in their creation. The Maker Revolution places strong emphasis on free (...
We deliver Australia-wide with these options:
- $3 for Small Items (4-6 days, not tracked, only available on selected small items)
- $6.95 for Standard Post (2-4 days, tracked)
- $8.95 for Express Post (1-2 days, tracked)
International Orders - the following rates are for New Zealand and will vary for other countries:
- $11.49 for Pack and Track (3+ days, tracked)
- $16.50 for Express International (2-5 days, tracked)
If you order lots of gear, the postage amount might increment based on the weight of your order.
Our physical address:
Unit 18, 132 Garden Grove Parade