Timeline for Can Digital/Analogue pins double as power supplies?
Current License: CC BY-SA 3.0
8 events
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| Mar 20, 2017 at 22:42 | comment | added | dandavis | again, I would use a real power rail for anything over 100mw or so... i'm not syaing power everything though it. i'm saying it can be fun to throw together an led and a temp sensor in 5 mins no solder ;) | |
| Mar 20, 2017 at 22:37 | comment | added | Ignacio Vazquez-Abrams | Right, but is far less than, say, a ESP8266 module needs. | |
| Mar 20, 2017 at 22:36 | comment | added | dandavis | @IgnacioVazquez-Abrams: sure, but 40ma is far more than most sensors use, a 4v triggers UNO's inputs... | |
| Mar 20, 2017 at 22:34 | comment | added | Ignacio Vazquez-Abrams | "25r limits 5v to 200ma" No, it means that if you try to draw 200mA you will get 0V. Even just 40mA means a drop of 1V, which will put it out of spec for most 5V or 3.3V devices. | |
| Mar 20, 2017 at 22:25 | comment | added | dandavis | the dht22 uses less than a ma. All but a couple of the "37 sensor" kit's modules would work with pin power; the relay+buzzers mainly. 25r limits 5v to 200ma, far more than the rated current... | |
| Mar 20, 2017 at 21:42 | comment | added | Ignacio Vazquez-Abrams | But note that the output pins have a not-insignificant impedance of 25ohm, which means that the more you draw from them the lower the voltage will be. | |
| Mar 20, 2017 at 21:17 | history | edited | Edgar Bonet | CC BY-SA 3.0 |
fixed: inputMode → pinMode
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| Mar 20, 2017 at 20:57 | history | answered | dandavis | CC BY-SA 3.0 |