Hi all,
I have purchased the Pololu D15V35F5S3 step-down voltage regulator.
I would like to use the D15V35F5S3 to power some devices in a remote location powerred by a small solar panel + batteries.
I would like to use enable pin on D15V35F5S3 to save as mucj power as possible so need to use the enable pin on D15V35F5S3.
Which is the best way to do it using Arduino digital pins using as less power possible on the Arduino side?
Thanks in advance,
Marco.
Hello,
Is the Arduino one of the things you are going to power with the regulator? It will not be capable of turning the regulator (and itself) off. On the other hand, if the Arduino is powered all the time, turning the regulator off just requires bringing the enable pin low, so I do not know what else you need to know.
The Pololu Pushbutton Power Switch can be used to allow an Arduino to turn itself off. Of course, it will not be able to turn itself back on!
-Paul
Thanks for your answer.
The Arduino will always being powered by the same battery, but will not be connected on D15V35F5S3 's Vout .
What I was asking is how to wire Arduino <-> D15V35F5S3 without frying all (does I need resistors, diodes, … )?
I am an electronic newby.
Have a nice day.
Hello,
Okay, that makes it more clear. I think you should just use a simple wire from a pin on your Arduino directly to the enable pin, without any resistors or other components. The enable pin needs to be driven down to zero (for off) and up to something above 2V (for on), so the digital_write function on the Arduino should control it just fine. As long as they are powered off of the same battery and share the same ground, this should work fine.
-Paul
I’m trying to do the exact thing, trying to use the enable line on my D15V35F5S3 regulator to turn it on and off, but I’m discovering that my Arduino (actually an Arduino Mega 2560, but that shouldn’t matter) cannot sink enough current to turn off the regulator.
I’m able to measure that the Arduino sinks about 80mA into the enable pin without turning it off. If I connect the enable pin to ground manually, it sparks a little and turns the regulator off. Unfortunately, I don’t have the equipment to easily measure the current required to turn the regulator off.
This seems to happen regardless of the load on the regulator.
Hello,
What you are describing is definitely not normal behavior. Can you please simplify your setup to the minimal number of pieces that you need to demonstrate the problem and then tell me what all of your components and connections are? For example, you could try using a resistor (> 100 ohms) to turn it off instead of the Arduino. A picture would really help describe what you are doing.
Please also check the voltage at EN under normal operation and inspect your soldering work carefully for any shorts. An accidental solder connection between EN and VIN could cause the problem you are describing.
-Paul
Well, that connection idles at 5V when not connected. It doesn’t appear to be connected to VIN, but it does seem to be shorted to VOUT, which would also cause this problem.
Thanks!
Hello,
Do you want any more help with this? If so, please do what I asked in my previous response. It would also help for you to describe how you can tell that it is shorted to VOUT.
-Paul
It’s fixed! I verified with my voltmeter in continuity test mode, but I had to spend about 30 minutes taking my project apart to get to the short and fix it, which is why it has taken me so long to get back to this. It turns out that I had a solder bridge on an interconnect board between the regulator and my Arduino; it’s a big project and a long story.
I am glad to hear that it is working for you now!
-Paul
