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So i am using an arduino clone gizDuino. Im connecting it to a lcd module. I successfully connected all the pins in the diagram, but when I connect it to the microcontroller the backlight doesnt power up. so I tried a 7.4v battery connected to the VIN of gizduino and one to the ground. It worked proplerly. I got the lcd module working(but without battery its not working). Then all set up and im ready to go to present my project but suddenly the gizduino doesnt power on when I placed the battery. I dont know what happened, I thought my board had a short circuit but when I connect it to the computer it seems working fine. Is anyone experienced this before to their microcontroller. PLS help.

NOTE: I haven't noticed any burn or smokes when I hooked up the battery

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  • \$\begingroup\$ did you test all the connection, it sounds more like a slack joint. take a multimeter and test all contact + battery \$\endgroup\$ – kimliv Feb 16 '14 at 23:43
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The power supply input goes to a 7805k regulator which feeds the MCU. The 78xx regulators need about 2 to 2.5v higher input than the rated output to work properly .
My guess is that the regulator was able to work correctly while the battery was full and stopped working as soon as the battery voltage dropped to 7v or so.

Also note that the datasheet of you device specifies an input voltage range of 8-12v for the power supply input, so the input you are trying to use is out of spec.

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On the GizDuino the Vusb supplies the VCC directly, where the Vin is linear regulated and may be current limited.

It does not take much of a load (aka minor short) to load the supply down a current limited supply. You should measure the current draw.

It may be current limited or its actual battery level is decay'ed below Vin(minimum) input.

The schematic of the GizDuino shows a UA7805KC is able to able to supply 2A. So it may be the battery.

Had it worked properly on Battery? then stopped.

It would be best to know what the Battery is? Battery Voltage VCC (or the +5V) Does the Arduino fail when the LCD is connected and on battery Are you saying the LCD only on battery is a problem or both on battery

Or you may just have a loose wire.

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  • \$\begingroup\$ At first it worked on the battery but suddenly it stopped working. Im using a samsung lithium 7.4v. There is no problem in the lcd. \$\endgroup\$ – NewInEverything Jan 18 '14 at 14:41

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