Powering Yun with Vin - tolerance?

I read on the Yun info page that the Vin on the Yun differs from other Arduino models in that its voltage is not regulated. Okay.. not too cool, but I'm trying to comply. I have a 5V 10A power brick from Adafruit to power LED strips and such. It's connected to a barrel jack on a shield I made which now goes to the Vin on the Yun, as well as to output headers which connect to the LED strip. My thing: the Yun doesn't seem to be booting correctly. The Yun doesn't necessarily seem broken because I can still power it using the USB port to power the Yun. It'll boot just fine then. I can upload sketches to the ATMega, ssh into the Yun, etc. However, when powering the Yun using the power brick it just seems like the Yun isn't booting. I have it connected to my network with the UTP cable.. should be seeing it on my network right?

Well, that's all I know right now.. does this ring any bell with you? Tips on what to try? And: is 5.34V okay for the Yun's Vin port?

Thanks!

I've not seen specific data for the Yun, but 5.3v sounds just about within tolerance - USB specifies 5V+- 0.25V, so you're a bit hot, but only just. Given you've not blown anything up, then its unlikely that its the problem: to low V and it will stop working, then work again with good power. To high V and it either works, or will never work again!

From your description of the project you're doing, I'm assuming you're using Bridge to communicate? This can cause problems, as the messages from Bridge can confuse the boot process. Try putting a generic blink sketch on the AVR, and power that from the PSU, and see if that helps.

You could also try running the system from a USB power brick, so see if it is a problem with your supply.

It's not a bad idea to run NeoPixels and CPU from separate PSU any way, as the neoPixels put out a LOT of electrical noise, which could mess with a CPU on the same power system.

dctsystems: From your description of the project you're doing, I'm assuming you're using Bridge to communicate? This can cause problems, as the messages from Bridge can confuse the boot process. Try putting a generic blink sketch on the AVR, and power that from the PSU, and see if that helps.

THIS IS ME GROANING. I can't believe I fell for that thing again (had a similar situation only 3 months ago). Yes.. adding a delay to the ATMega boot process allowing openWRT to boot without unnecessary Serial chatter was the ticket. Thanks so much for the reminder.

Also, thanks for the warning about NeoPixel noise.

If you want, you can upgrade your Uboot image to avoid this problem.

The new Uboot image requires the "ard" char sequence to stop the boot process, so if you Arduino sends serial data while the Linux side is booting it won't stop the boot.

http://arduino.cc/en/Tutorial/YunUBootReflash