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@ -83,10 +83,17 @@ Plug US1 into PC or USB charger and board should power up.
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Initial voltage rise at USB 5V line will trigger board powering
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up and holding the power.
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USB-serial chip FT231X will always be powered from 5V USB
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on PCB v1.7. The board has switching voltage regulators
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On PCB v1.7, USB-serial chip FT231X will always be powered from 5V USB.
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The board has switching voltage regulators
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which can be turned off to reduce power consumption.
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On PCB v2.0 and later, USB-serial chip FT231X will be directly
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powered only from US1. If board is powered from US2, there is diode
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preventing 5V to FT231X power pin, but FT231X will still be weakly
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back-powered from its other pins connected with rest of the board
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and it will appear as some load. For most practical cases, we
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are lucky that FT231X appears as high-z when not directly powered.
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Green LED D18 behaviour is the "Power LED". Green LED ON will keep
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board powered up. By factory default, when USB-serial chip
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is enumerated by PC, Green LED will turn ON.
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emard
6 years ago