With an input Voltage at 12V from a battery, I needed a 5V out. I looked at the schema of both your Moteino and MEGA, I don't think there is anyway I can get a pin with a 5V out.
Or is there?
If not, any simple suggestion that I can make it happen?
Thank you as always.
Have you looked at the spec at lowpowerlab.com/moteino ?
It's a pretty good place to study and get a lot of answers.
Moteinos are 3.3v devices. No 5v anywhere.
Hi Felix,
Thank you for your quick reply. Just trying to beat up a dead horse.
I know it is a dead end. Just needed to make sure.
:-)
Donald
Quote from: donaldhwong on January 06, 2015, 12:05:58 PM
Hi Felix,
Thank you for your quick reply. Just trying to beat up a dead horse.
I know it is a dead end. Just needed to make sure.
:-)
Donald
Donald,
you'll need a separate 5V regulator, powered from your 12V supply and, then, to interface between Moteino signal pins and your 5V device(s), you can use a circuit similar to what is used in a SparkFun level converter (unless you need high speed signalling - then you'll need a powered level translator):
https://www.sparkfun.com/products/12009
Just hit the schematic link for the implementation.
Tom
Wow, Tom comes to the rescue. Thank you very much Tom.
I googled for such solution and found it costs me nothing, if I break open my old mobile phone car charger and use the circuit as is.
On a second note, I need to confirm with Felix that Moteino, R4 and MEGA can both work under a 12V supply??
Thank you again for your enthusiasm and support.
Donald
Again, help us help you. Please go to http://lowpowerlab.com/moteino/#specs where you will see the spec for the VIN pin max voltage.
Hi Felix,
Thank you for pointing that out. That's where I found the spec and my question is based on that.
I just need your personal assurance that it will work at 12VDC without any issue.
Just being careful.
Thank you for your continual support.
Donald
Yes it will although it's very inefficient to feed that high of a differential into the Moteino voltage regulator. I usually recommend up to 9V but 12V will work.
Hi Felix,
Thank you for your continuous support.
I truly appreciated.
Donald
Hi Felix,
Hooked up one R4 Moteino with 12VDC power supply. It fried.
Not sure your store warrant your product. If you do not warrant product after our malpractice, I will order another one. No worry.
Thank you,
Donald
How did you hook it up?
12 VDC through the USB. Ah, I just realized that I should not go through the USB.
I should have hooked it up to the VIN pin.
Sorry that I have troubled you.
Donald
Yeah ... external power has to be always applied through the VIN pin.