LCD in car shows random characters scrolling

Hi!

I am using my arduino in my car and the LCD (HD44780) is starting to scroll random characters fast when the engine is running. I think this is something voltage related issue. The Arduino Mega 2560 R3 (chinese clone) is connected though the power input socket and it connects to the radio's +12V. When the engine is running it is around 13-14.4Volts, so maybe thats the problem.

Should i use a voltage regulator with capacitors to create a more stable voltage, like 8-10V? Or do you have any other suggestions?

Thank you

ponsumkey:
Hi!

I am using my arduino in my car and the LCD (HD44780) is starting to scroll random characters fast when the engine is running. I think this is something voltage related issue. The Arduino Mega 2560 R3 (chinese clone) is connected though the power input socket and it connects to the radio's +12V. When the engine is running it is around 13-14.4Volts, so maybe thats the problem.

Should i use a voltage regulator with capacitors to create a more stable voltage, like 8-10V? Or do you have any other suggestions?

Thank you

Yes, you must.
(And a good one)

Hi,
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html.

If all your Arduino circuitry is operating off the Mega 5V pin, then yes you have a problem with the Mega's linear 5V regulator overheating due to the high input voltage.

Suggestion, power your 5V components, including the Mega off a 5V USB adapter plugged into the 12V power socket.

You may also need to add bypassing components around your project.

What does your project do?

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks.. Tom.. :slight_smile: