LowPowerLab Forum

Hardware support => Moteino => Topic started by: jimh on June 16, 2014, 03:43:06 AM

Title: Killed voltage regulator on R4. Need help.
Post by: jimh on June 16, 2014, 03:43:06 AM
I made the mistake of trying to set up a new project late at night and reversed the wires.  I saw the smoke and knew it was gone.  Fortunately all is not lost since plugging into the 3.3v pin still works.

However, trying to program it with the USB FTDI doesn't work.  It doesn't seem like it powers up. 

I'd love to get this fixed/replaced, but I don't have the know-how or parts.  Where would I be able to buy the exact part for the voltage regulator?  (A direct link would be most helpful since I haven't had much luck finding the exact one.)

Of course, if anybody has the part and is willing to help me out by replacing it for me, for a small fee, I'd look into that as well.
Title: Re: Killed voltage regulator on R4. Need help.
Post by: Felix on June 16, 2014, 08:25:25 AM
Jim, I can send you the replacement if you cover postage. Or you can get it here: http://www.digikey.com/product-detail/en/MCP1703T-3302E%2FCB/MCP1703T-3302E%2FCBCT-ND/1776945
Title: Re: Killed voltage regulator on R4. Need help.
Post by: ssmall on June 16, 2014, 12:53:50 PM
I smoked one of my Moteinos, how can I tell if it is the voltage regulator?
Title: Re: Killed voltage regulator on R4. Need help.
Post by: Felix on June 16, 2014, 01:13:51 PM
Desolder the regulator if you can then supply 3.3V on the "3.3V" pin (or 2xAA batteries should also work).
If the mega328 is still alive it will work and you should be able to upload a sketch.
Title: Re: Killed voltage regulator on R4. Need help.
Post by: ssmall on June 16, 2014, 03:05:29 PM
"Desolder the regulator if you can", you must be familiar with my desoldering skills.  ;)
Title: Re: Killed voltage regulator on R4. Need help.
Post by: Felix on June 16, 2014, 03:15:36 PM
Well in that case just try 3.3V on the 3v3 pin and see what happens, can't do much more damage now anyway.
Title: Re: Killed voltage regulator on R4. Need help.
Post by: jimh on June 16, 2014, 11:42:40 PM
Thanks Felix for your offer.  I sent PM.

With the USB FTDI set to 3.3v, can I route the 3.3v to the Moteino 3.3v line for it to power on and be programmable?
Title: Re: Killed voltage regulator on R4. Need help.
Post by: Felix on June 17, 2014, 07:55:24 AM
I actually never tried that myself I don't think. So I can't be sure if the 3.3v provided by FTDI is enough to power the radio but purely for programming it should suffice. In RX mode the radio is just 16mA. Do you have a 2xAA holder? You could just power the "3.3" from two AAs... if not then you can try the FTDI...