Help: Problems Powering Moteino from SonarMote PCB

[brandock]

I could use some help. I soldered together the SonarMote kit and charged up a LiPo battery. When I connect the Moteino to the board the Moteino does not seem to get power (LED doesn't light up), neither when connected to battery nor USB. The Moteino is working when I have it off the SonarMote PCB and connected to a power source, both with VIN and with the FTDI connector, so the Moteino doesn't seem to be the problem. When I connect the Moteino to the SonarMote PCB the Moteino's LED goes off, even if it is connected to power through the FTDI header.

I was thinking maybe I had a short in my soldering under the analog-pin female header on the board (the one with A7 labeled for battery monitoring). So I desoldered that header and started testing with my the multimeter directly on the SonarMote PCB holes, with no Moteino attached. Here's what I find.

With SonarMote PCB connected to USB:
Reading across VIN to GND (the holes for the analog side of the Moteino) I get 0.00, regardless of switch position
Reading across A7 to GND, I get .42 when switch is on, 2.66 when off.
Reading across A6 to GND I get 3.28 regardless of switch position.

When connected to LiPo:
Reading across VIN to GND (the holes for the analog side of the Moteino) I get 0.00, regardless of switch position
Reading across A7 to GND, I get .14 when switch is on, 2.6 when off.
Reading across A6 to GND I get 0.00 regardless of switch position.

Does this make sense?
Thanks,
Brandon

[Felix]

Brandon,
Does the board get recognized by your computer?
Either way it sounds like there's a problem with the power path from the USB/LiPo to the VIN pin that powers the Moteino. It's hard to guess what could be wrong without me looking at the board physically. I would be more than happy to take a look at the board and fix/replace it for you if there's a problem. For that you would need to return it.
Or if you are willing to spend more time trying to debug it through high res closeup photos maybe that could help... its up to you.

[brandock]

Hi Felix,

The board is recognized by my computer. I agree there seems to be a problem with the power path to the VIN pin that powers the Motion. I desoldered everything, in case I could find a short that way, but no luck. My multimeter says there is continuity between that VIN hole and GND next door to it.

Thanks for offering to take a look at the board. I will send it back to you, both because I'd be interested to see if you can figure out what went wrong with my soldering, and because I'd like to get a working board for my project. Thanks!

Brandon

[Felix]

Ok Brandon,
Either mail it back to the address it was sent from in Canton MI or contact me over email to get you details.
Thanks,
-Felix

[Felix]

Brandon,
Got your board, analyzed it and I could not find any fault. When enabled (via switch pins) the VIN header for the moteino receives the ~4v from the LiPo.
I also powered a Moteino with it, it runs fine. Setting D5 high will also enable the 5V booster and 5V is present on the HCSR04 header.
Plugging USB works as expected and charges the LiPo.
There's a chance you might have shorted the switch when you soldered it, I've seen this before. Which causes the LiPo output to be shorted to GND.
I cleaned up the plugged headers and soldered another switch and tactile button for you, verified it still works. Will mail it back tomorrow.
Keep in mind battery polarity is crucial for this to work correctly.
Let me know if you have other concerns before I do that.