Hey all,
I may need a little help with my cosplay project.
I got everything running (semi-) smooth while the Arduino Nano was connected to USB and external power at the same time. As soon as I run the thing only via external power, all components that get switched on/off by the Nano are switched on. The Nano also isn't showing any signs of power (no LEDs are blinking/on).
When I measure between GND and VIN pins I only read ~2.3V which doesn't seem right. However, when I push any of the two buttons, the Arduino is getting power and the components behave "normal".
There has to be something wrong with the electronics setup / circuit, so here is the circuit diagram:
So that's a smoke alarm battery? That's your problem. Do a little calculation, figure out what your circuit might draw. I'm betting the circuit has already bled the battery dry, hence the 2.3V reading.
Worse idea. Vin needs 7.x V minimum. Don't believe me? Find the datasheet for the regulator (don't believe the Arduino published values, someone with a side of optimism wrote those).
You need to either provide > 7VDC(stable DC) to Vin, or provide 5VDC(again, stable) to the 5V pin.
But he isn't, that's clearly a separate source(not identified, just a label).
The FETs have pulldowns, so I expect they're truly off, at least until the outputs become outputs. I don't see anything else that will preclude the Uno powering up, though it might go to it's knees the moment any of the overloaded outputs are driven low.
Just what does that conflicting statement really mean? 2.3V at Vin is definitely wrong. Unless ~2.3V means AC 2.3V, though that's also 'wrong'. If you've got 2.3V at Vin, no LED activity, but the components behave "normal", IDKWTF.
Well, I wanted to just switch the motor and coil on with the button but at the same time pull the D8 PIN low when pushing... thats why they are connected to ground when the button is pushed. Is there a current flowing from D8 to battery +9V??? I've set D8 to Pullup but it should be max. 5V right? So there is a difference in potential at motor (+) of 9V and D8 of 5V which means the Arduino should never power the motor right? Am I missing something?
Even if so, it worked when USB was connected... LEDs should be dimmer but at least work right?
That was the final plan... the circuit is currently powerd by a lab bench PS...
Why not btw? At max. power the strip will draw ~13W/meter. I calculated the whole circuit to draw max. 40W at short times and around 20W continuous.
So there is a difference in potential at motor (+) of 9V and D8 of 5V
By that theory, the motor is seeing 4V, because D8 is motor(-).
Any device connected to BAT2+(9V) on one side, but not pulled low by an active output, will pull that output to (close to) BAT2+. They effectively act like pullups. 9V is way more voltage on those pins than the Arduino is rated for(5V, plus an internal protection diode, so think 5.5V max).
The components should not be all on/glowing full brightness when the Arduino is behaving normaly. Which is the case when connected to USB and external power. The moment I use only external power, everything except the Arduino and the motor/coil is on. (Everything that is connected to a digital pin)
When you connect close to 9VDC to more than zero digital pins, input or output, all bets are off, because the internal protection diodes of those pins are forward biased and all hell is breaking loose internal to the chip. I'm not surprised the other pins are providing enough current to drive the FETs on, now.
Well I think I understand now... I couldn't get the motor to spin full power with the FET, so I just connected it directly and all the other FETs are open because of this and it seemed to work because the extra 5V from USB helped stabilize the Nano?!
So I just need to get like IRF470s and drive the motor/vape and the other things through it?
