3 ms·
A mosfet seems pretty overkill for this instead of practically any cheaper transistor unless there’s something about motherboard headers I don’t know. Pretty co
by lloydatkinson 4y ago
A mosfet seems pretty overkill for this instead of practically any cheaper transistor unless there’s something about motherboard headers I don’t know. Pretty cool though.
- secure 4y agoCheaper transistors should totally work, as I tried to describe in the article. I had this particular MOSFET lying around from a different project, so that’s the main reason I chose that one :)
- sokoloff 4y agoIt’s also only $0.46 in singles at DigiKey, so hardly something crazy wasteful in any event.
- dekhn 4y agoWhy is the transistor needed at all? Does the current to turn on/off the machine exceed the ESP32's pins?
- jstanley 4y agoBecause you need to act like a switch.
- dekhn 4y agoI mean, you can use a GPIO on a microcontroller as a switch if the current is small enough... this device is not directly in the path of 120V, it's just twiddling a GPIO on the motherboard... right?
- numpad0 4y ago> void setup(){ pinMode(PWRBTN, INPUT); } > void press(){ digitalWrite(PWRBTN, HIGH); delay(33); digitalWrite(PWRBTN, LOW); delay(33); digitalWrite(PWRBTN, HIGH); } My 5min hack would look like this - and optionally a 0.1uF and a 1k resistor for peace of mind - totally untested though. Usually a uC I/O pin has three states; output high, output low and Hi-Z. Hi-Z is high-impedance or extremely high resistance state, analogous to an open circuit.
- dekhn 4y agoRight, just toggling a GPIO. From what I can tell, there is some claim of 5V 500mA for a short period when doing this, which would explain the transistor.