This time I decided to give you a slowmotion explanatory video demonstrating the new key scanning technique my SMD sensor board features. Recall that this technique is supposed to reduce power consumption by 75 % while minimizing crosstalk effects:
In the video you can see which IR leds are switched on (blue spot). The flash numbers show you when which ADC channel is read by the controller. You will notice that there are always 2 IRLEDs on: The one that was recently scanned and the one that is to be scanned in the next cycle. The switching occurs during an unused ADC cycle thus avoiding current spikes generated by the switching ruining the ADC measurement.