FX Board
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- dastels
- Posts: 15608
- Joined: Tue Oct 20, 2015 3:22 pm
Re: FX Board
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
I think that answers your question. If not, please rephrase.
Dave
- eelloyd
- Posts: 2
- Joined: Mon Jul 26, 2021 8:18 am
Re: FX Board
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?
- dastels
- Posts: 15608
- Joined: Tue Oct 20, 2015 3:22 pm
Re: FX Board
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
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
Please be positive and constructive with your questions and comments.