QTRX-HD-07A Reflectance Sensor Array.This sensor module has seven (7) IR LED/phototransistor pairs mounted on a high-density 4 mm pitch, making it well suited for precisely identifying changes in contrast/reflectance (like line-detection). Unlike our original QTR modules, these units offer dimmable brightness control independent of the 2.9 V to 5.5 V supply voltage, with optional separate control of the odd and even sensor channel emitters. The optimal sensing distance is approximately 1 cm or less, but high-reflectance objects are generally detectable out to around 5 cm. This version features high-performance QTRX sensors with lenses, and each sensor provides a separate analog voltage output. Max LED current is set to 3.5 mA, and the max board current is 15 mA.