LED photometry using the Paired Emitter Detector Diode (PEDD) strategy has been demonstrated to be a viable sensing method for analytical measurements. Timing of the LED discharge is one of (if not ‘the’) primary factors in this approach, and can have a significant impact on sensing characteristics, such as resolution or the limit of detection (LOD). Details of these timing implementations have not appeared in the literature thus far, making reproducibility and comparisons between systems challenging. This study investigates a number of timing implementations and demonstrates that the difference between these methods can impact resolution by up to 68%. Specifically, the three methods are based on a variety of Arduino functions and base C registry readings for the logical operations (comparison and reading the digital I/O status), i.e. (1) ‘Wiring: digitalRead(), if()’, (2) ‘C: Register, if’, and (3) ‘C: Register, switch()’. Additionally, during a deeper analysis, it was
Carl ist ein einfach zu bedienender MP3-Player für Kinder, der reichlich Platz für Musik und Hörspiele bietet. Wie man ihn baut, zeigen wir in der Make 4/21.