WindSensor RevP

I'm trying to get my Wind Sensor RevP to work. Unfortunately, something seems screwy with my Arduino - I have it hooked to a 12V external power supply, but only get 3.95V out of the Vin pin. This results in "nan MPH -25 C" being the output in the serial monitor. Guides and arduino forum posts seem to make it out that this is supposed to be easy. Which it probably is if my Arduino Vin pin output 12V like it's supposed to.

Anyway, I bypassed it and simply hooked up 12V directly to the device, but forgot about current, so I'm pretty sure I cooked the wind sensor (I have backups fortunately) at 5 amps. I'm unfamiliar with how to work with transistors, but have some (BC548CTA and TIP120) on the way for other parts of the project to downstep a 160 mA device to work with arduino, and a solenoid valve to work with the arduino.

Will either of those transistors also work with the windsensor if I flip the transistor around, or do I need to figure out how to fix the Vin pin?

ViaXTquestions: I'm trying to get my Wind Sensor RevP to work. Unfortunately, something seems screwy with my Arduino - I have it hooked to a 12V external power supply, but only get 3.95V out of the Vin pin. This results in "nan MPH -25 C" being the output in the serial monitor. Guides and arduino forum posts seem to make it out that this is supposed to be easy. Which it probably is if my Arduino Vin pin output 12V like it's supposed to.

Anyway, I bypassed it and simply hooked up 12V directly to the device, but forgot about current, so I'm pretty sure I cooked the wind sensor (I have backups fortunately) at 5 amps. I'm unfamiliar with how to work with transistors, but have some (BC548CTA and TIP120) on the way for other parts of the project to downstep a 160 mA device to work with arduino, and a solenoid valve to work with the arduino.

Will either of those transistors also work with the windsensor if I flip the transistor around, or do I need to figure out how to fix the Vin pin?

What part of "Vin" does "in" mean to you? What does "V" part mean to you? Does "in" mean"out"? I don't think so.

Paul

What all do you have connected to the (mystery) Arduino? Can you provide a schematic of the entire project?

The recommended max power dissipation for the onboard 5V regulator (Uno, Nano, Mega) is 1 Watt. With 12V to Vin the regulator must drop 7v. That means that the max current that the regulator can safely supply is
1W / 7V = 143 mA. The Arduino needs about 50mA, leaving less than 100mA for everything else that is connected to the 5V regulator. Drawing any more current than that will pull the supply voltage down and eventually the regulator will get hot enough to shut down.

Paul_KD7HB:
What part of “Vin” does “in” mean to you? What does “V” part mean to you?

“V” means voltage. “In” refers to the voltage coming from external supply that’s been plugged in. Defaults to 5V from USB if no external is connected, and the max that people in these guides tend to use is 12V. Kinda counterintuitive, but they’re italian, so who am I to judge.

groundFungus:
What all do you have connected to the (mystery) Arduino? Can you provide a schematic of the entire project?

The recommended max power dissipation for the onboard 5V regulator (Uno, Nano, Mega) is 1 Watt. With 12V to Vin the regulator must drop 7v. That means that the max current that the regulator can safely supply is
1W / 7V = 143 mA. The Arduino needs about 50mA, leaving less than 100mA for everything else that is connected to the 5V regulator. Drawing any more current than that will pull the supply voltage down and eventually the regulator will get hot enough to shut down.

Sorry, It’s a MEGA2560. The Windsensor RevP draws 40mA according to their site.
Any ideas on how to fix Vin? Some Guides Say replacing the regulator. But I am certainly not confident in my soldering abilities to do that even if I order the right part.

Not all parts are here yet, so fritzy schematic is attached. There’s going to be a small 5V fan (160 mA which is why I have the BC548), a PM2.5 sensor (which works), and then the wind sensor.

Maybe I should just throw a big resistor in after (- side?) the WindSensor? I can’t get a resistance reading off the extra Windsensor. Since transistors typically amplify current and voltage instead of step it down?

I’m new to this clearly. I’d prefer I didn’t cook too many devices.

Vin comes from the barrel jack thru a reverse polarity diode, Vin then feeds into the 5V regulator.
Pretty sure one will not see the USB voltage at that pin when fed from a PC or other 5V source connected to the USB connector.