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(Incremental Encoder)
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Shaft Rotation Sensor
This rotation sensor or incremental encoder (unlike potentiometer) has no limit
for number of counting. It can also detect clockwise and counter clockwise
rotation and thatʼs why it has 2 pins (SIA and SIB) for detecting rotation.
Basically, it translates the rotary motion into a sequence of pulse signals. By
comparing the square wave generated from each of the two pins you can
determine the direction of rotation (as shown in Figure below) and by counting
the number of pulses you can determine both the rotation angle and the RPM of
the rotating shaft. A reset button is provided to reset the counter to zero state
when needed to start counting again.
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Features
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Operating Voltage: 3- 5V
NOF pulses per Cycle: 15 pulses
NOF Cycles:
unlimited
Reset Button: reset counts to Zero
Clockwise and counter clockwise rotation direction detection
Dimensions: 32 x 15 mm
PIN Definition
SIA: Signal A (pulse)
SIB: Signal B (pulse)
SW: State of reset pin (0 or 1)
GND: Ground signal
VCC: voltage (3 - 5V)
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Arduino Connection
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SIA ----------------------------> D2
SIB----------------------------->D3
SW----------------------------->NC
GND--------------------------->GND
VCC---------------------------> 5V
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#define PinA 2
#define PinB 3
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Arduino Code
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unsigned long time = 0;
long count = 0;
long num = 0;
void setup()
{
Serial.begin(9600);
pinMode(PinA,INPUT);
pinMode(PinB,INPUT);
attachInterrupt(0, blinkA, LOW);
attachInterrupt(1, blinkB, LOW);
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time = millis();
}
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void blinkA()
{
if ((millis() - time) > 3)
count ++;
time = millis();
}
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void loop()
{
while (num != count)
{
num = count;
Serial.println(num);
}
}
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void blinkB()
{
if ((millis() - time) > 3)
count --;
time = millis();
}
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