Marlin firmware fork for MakerFarm i3v w/ auto bed level & Roxy's enhancements

[printbus]

My LCD will go blank at random times, but always if the Z probe on the servo contacts the bed before retracting. The reason for me is the Arduino board doesn't have the voltage needed when the servo stalls momentarily if it contacts the bed during retract. Even after I installed the advanced G29 code from Roxy with the DACB fork and solved bed interference problems with servo retract since the new code does a Z raise before retract, I had a couple of isolated incidents of the Arduino rebooting due to lack of power. The solution for me was simple, just keep the USB cable connected to my laptop whenever the printer is turned on. Even with the laptop closed and sleeping it provides additional 5v through the USB to the Arduino board. It would probably be better to provide additional 5v power from another source to the Arduino, but since this works perfectly for me I just haven't bothered yet. If your LCD resets, it is likely a power to the board issue. Figure out a way to provide more power and it might solve the problem for you as well.

Yep. I go into the numbers starting with this post in my build thread - http://3dprintboard.com/showthread.p...ll=1#post28854. After looking at the design of the MEGA2560 board, my conclusion is that the on-board 5V regulator is pretty much maxed out with the basic LCD-equipped MakerFarm printer. If you add an ABL servo or any other 5V loads onto the printer, you should provide your own 5V source or keep the printer USB port plugged into something that can provide 5V power via USB, thereby bypassing the on-board regulator. I can't help but wonder how many ABL issues are caused by people trying to run the printer standalone off a 12V supply.

FOLLOWUP COMMENT: Stalling a servo will cause the current draw to the servo to surge, further increasing the likelihood of a problem. And my guess is the LCD going blank is likely a sign that the Arduino board is undergoing a reboot.