An assist assembly incorporated into a dispensing gun supporting an elongated cartridge containing a volume of a flowable material. Light received from the filters of some colors is used to locate the color symbol, while light received from all the filters is used to read and decode the located symbol. The first AP hides an SSID in beacons broadcast by the first AP. Last but not least, the induction coil is screened from external electric fields in order to avoid the influence of parasitic capacitances.