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[on:]

I just got my arduino nano V3.0 today. I also got an SD card reader and an LCD screen. I decided to connect a speaker to it and use the SD sound library to play music and display stuff on screen. I had it all working good and i was listening to some music when all of a sudden there was a crackle and then the music glitched a little. I then noticed a low hum in the background of the music that wasnt there before. The LCD screen was dim when i looked at it and the back light was flashing lightly. I looked back at my computer and saw "USB device not recognised." down the corner.

I reset the board using the reset button. The board's LED seemed to flicker for about 20 seconds before it started to display stuff on the screen like it was meant to. The board gets stuck with the LED flickering for upto 3 minutes so far. The speaker is quite, USB wont connect, display shows corrupt characters and the volt meter shows 3.1volts on the 5v pole and 3.0v on the 3.3v pole with nothing connected.

Is there any way to fix this? What is broken? What other information do you need?

[Reply #1 on:]

How did you power it? Only the USB power ? That might be not enough.
How did you connect the speaker, directly to an output or with a resistor of 100...150 ohm.

Disconnect everything, and try to make the Arduino Nano run on its own.
You can use this sketch : http://playground.arduino.cc/Main/ShowInfo
If that is okay, connect the LCD and try that. If that is good, try adding the SD card module.

[Reply #2 on:]

Perhaps something shorted out.

Is there any way to fix this? What is broken? What other information do you need?

Schematic and links to the hardware you used.

[Reply #3 on:]

I only used the usb power. The voltage readings are the same with the arduino unplugged from the project. The nano seems to be rebooting now. It plays about 1 second of sound and then the rx and tx lights flash even if its connected to a wall plug to usb adapter. Plugging the LCD into an external 3 battery (4.5v) power supply it works fine.

[Reply #4 on:]

I just looked at it now and the device connects to the computer if i ground the reset pin. Im able to do a loop back test and i can see what im sending. As soon as i remove the jumper from reset to ground, the computer says usb device not recognised.

[Reply #5 on:]

I think it's just a case that all your stuff is drawing more then the 500ma current limit when using USB power.

Note that unlike most arduino boards there is no 500ma thermofuse to protect the PC's USB port from excessive current draw, so beware how much current your nano based project requires and keep it under the 500ma USB limit, or power the nano and/or extra stuff from an external voltage source.

Lefty

[Reply #6 on:]

I think it's just a case that all your stuff is drawing more then the 500ma current limit when using USB power.

Note that unlike most arduino boards there is no 500ma thermofuse to protect the PC's USB port from excessive current draw, so beware how much current your nano based project requires and keep it under the 500ma USB limit, or power the nano and/or extra stuff from an external voltage source.

Lefty

My laptop has a current limit of 1A(1000ma). The volt meter reads 4.8v coming through the usb port with the nano plugged in. But after its gone through the circuits the 5v line ends up as 3.2v. The RX and TX lights flash even if the usb is unplugged. The program runs until the RX and TX lights start flashing and then the speaker crackles and the program resets. While the RX and TX lights are flashing, the 5v line goes to 2.3v and the 3.3v line goes to 2.4v. I have a 4.5v battery pack, where do i plug it in? 5v line, vin line?

[Reply #7 on:]

I just upgraded the 25v 47uf capacitor to a 16v 210uf capacitor and its running. 5v pin is at 4.2v now. 3.3v pin is at 3.3v. The USB port is not under powered. The RX and TX lights would be flashing because of the USB controller resetting from low voltage yeah?