Fairchild QRB1114 Sensor

How to use the Fairchild Semiconductor QRD1114 Opto Switch Sensor

The Fairchild QRD1114 Reflective Opto Switch can be attached to a microcontroller such as those found in the Atmel range, including ATMega8 and relations such as the ATMega88 as used in this instructional.

To connect the QRD1114 to your chosen microcontroller you may use the circuit illustrated above, here pins 2 and 4 are connected to ground, pin 3 is connected to a +5 DC source via a 220Ohm resistor and pin 1 is connected to a suitable ADC (Analogue to Digital converter) input pin and then a 10 KOhm resistor (pull up) and on to a +5V DC source.

This arrangement will yield an input voltage of between 0 and +5V.. Depending upon the resolution of the ADC selected a digital value will be returned when the ADC value is sampled. For an 8 bit ADC conversion this value will lie between 0 (0 V approx) and 1024 (+5V approx). This digital value is then usable by your program.

How orient the Fairchild Semiconductor QRD1114 Opto Switch Sensor

The position of Pin 1 is marked with a small indententaion on the face of the QRD1114, this can be seen highlighted in the picture below.

The position of all the pins is shown on the picture below, note this sensor is viewed from the FRONT in the picture.

With robot minisumo edge detection the values for the matt black inner circle of the dohjo and the matt white outer edge are determined. The robot minisumo program then reads the QRD1114 periodically and when a variation from the predetermined matt black value is detected the sumo takes appropriate action, such as turning away from the Dohjo edge.

NB: This instructional will be updated with more infomation soon