lawsie wrote:Thanks - no we were not using any breakout board or indeed any breadboard at all, just wires and the LEDs.
The LEDs I am currently using are some dodgy cheap ones from Amazon. The specs say:
Forward Voltage : 2.0 - 2.2V
Max Continuous Forward Current : 20mA
http://www.amazon.co.uk/gp/product/B008 ... uctDetails
I plugged in those numbers and it suggested a 68ohm resistor but I have no idea whether that is sensible or not.
As well as the other suggestions, I have seen LEDs for sale that work directly from 5V - they either have a resistor or some other current limiter built in. (I don't know which - never used them as of course they're more expensive than normal LEDs!) So maybe something like that was used. Or perhaps the resistors were built into the wires and shielded with heatshrink - they would be very thin and not obvious. (Actually that may be a good thing to do if building kits for kids, etc.)lawsie wrote:2. How come we didn't use resistors in Picademy and it still worked - is it just because we only did it for a really short time, or is it not necessary for this particular case for some reason?
yes, they are OKlawsie wrote:Something like this?
http://www.amazon.co.uk/Carbon-Resistor ... +resistors
Possibly.spagi wrote:... I get a value of 39ohms. Am I doing this right?
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