Hi, I had unexpected magic smoke and just want to confirm. I have pro mini clone and a 128x64 lcd with back lighting. I had run it from the programing connection with usb and all was fine. Then I powered it at the raw pin with 12 vdc and connected lcd power on vcc. It ran fine a short while, less than 1 minute, then vcc went to 12 vdc as well. just want to confirm that the reg on the mini was not up to the tast and I need a 5vdc supply just for the mini. ( I need 12 vdc for the transistor switched output )
Best to all, Tom
Best thing would be to post a schematic (drawing) of how it all was connected.
Definitely need a diagram of how it was wired.
You should be able to supply it with 12v on RAW pin without issue.
I don't know how else to describe it. I know ( I think ) it can be powered at raw pin with 12 v, but how much current can be loaded on vcc? The other (output power) has nothing to do with it, only the LCD is attached to the arduino.
upon further reading it looks, but does not clearly say, that the vcc pin is input only for regulated 5vdc. So not meant to supply and power out? How do you power your LCD if your main power source is 12 vdc?
No, Vcc is the correct way to get 5v out. You can't get all that much current out, since it has to dissipate the energy as heat and it's a rice-grain sized part (if you need more current, use an external voltage regulator - either linear (like a 1117-series) or a dc-dc step-down converter for higher current and greater efficiency, at a cost of higher standby power consumption and greater complexity (search ebay for dc-dc step down in industrial and test equipment - you'll get results starting at about $1 counting shipping)
Please post a schematic showing all of the connections. A picture of a neat hand drawn schematic is fine. We need to see exactly how everything was wired. Also, what kind of screen? Post link to the product page you got it from.