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QRD1114

QRD1114 Resistor Values

Hi all,

I'm using a QRD1114 sensor for a line-follower. Datasheet: http://www.fairchildsemi.com/ds/QR/QRD1114.pdf

Im hooking it up with this schematic:

However, I'm unsure how the value for the 10K resistor was calculated? It's acting as a potential divider, right?

For the LED im guessing that the value of 220 was taken from doing:

R=(Input Voltage - Max Forward Voltage)/(Optimum forward current)

Just fixed some URLs to images, no real updates, this bloke has been disassembled for ages. This is my entry for the 2011 Swedish National Robitcs Championship. It … Read more

Picaxe Encoder wheel timing

I am using the code below to monitor 2 encoder wheels connected to (pin4 left motor QRD1114 & pin3 right motor QRD1114) on my latest 28x1 picaxe project . It works fine .

My question is :- how can i calculate how long the code takes to execute?

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