FX Board

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eelloyd
 
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FX Board

Post by eelloyd »

Can the ACTIVE output signal handle the current of an LED directly?

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dastels
 
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Re: FX Board

Post by dastels »

The LED is connected to GPIO12/ACTIVE. There's no driver transistor. There's a current limiting resistor, but that's to set the current going through the LED so it doesn't burn out.

I think that answers your question. If not, please rephrase.

Dave

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eelloyd
 
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Re: FX Board

Post by eelloyd »

Allow me to rephrase... Making the following assumptions - an LED rated at 1.2 volts with the anode connected thru a 95 ohm resistor, (calculated for 20ma.), going to a VCC of 3.7 volts. The cathode end of the LED going to the low=ACTIVE, (low being +.6 volts above ground), connection of the GPIO. Can this output sink the current required to illuminate the LED, with not requiring any additional components, and not burn out the GPIO?

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dastels
 
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Re: FX Board

Post by dastels »

That's more or less what's happening on the board with the ACT LED, albeit with a 470 ohm resistor.

I don't see any current source/sink numbers for the GPIO pins on the data sheet: https://cdn-shop.adafruit.com/datasheets/vs1000.pdf.

Dave

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