Go Down

Topic: DC Powerjack on a PCB with Arduino Mega (Read 180 times) previous topic - next topic

masterheavy

I would like to use an external DC power jack to power my Ardu Mega and I build a PCB for it.
(a lot more will be on that PCB - but for simplicity its a PCB and i solder the jack on it)

the PCB is one sided and will have a groundplane for GND.

So the GND of the Mega is connected to the groundplane.

Do I connect the gnd of the powerjack to the same groundplane?

Cheerz 
de Heavy

Paul__B

Not sure what you are trying to say here, but you do not want to be powering a Mega via the "barrel jack" or "Vin" for any serious project.  It requires a regulated 5 V to the "5V" pin - except when you have it plugged into a PC for programming.  Do you have a 5 V power supply?

masterheavy

#2
Jan 17, 2021, 10:42 pm Last Edit: Jan 17, 2021, 10:50 pm by masterheavy
I have a 9V power supply 1000mA and it sais Vin is suitable 7V to 12V
I have used that with the barrel jack in the past.

the project is a simple Midi Controller that only sends a few analog signals via a Midi Out Din 5 - so its not that serious.

Wawa

#3
Jan 18, 2021, 04:02 am Last Edit: Jan 18, 2021, 04:02 am by Wawa
Plugging the Mega's USB lead into a 5volt cellphone charger with USB socket is a lot easier.
Leo..

masterheavy

The MidiController is for a studio setup. Plugging USB in and out is more complicated then having an ON/OFF switch on the device.

septillion

#5
Jan 18, 2021, 08:39 am Last Edit: Jan 18, 2021, 09:31 am by septillion
Two suggestions:

- Have a power strip with a switch
- Just leave it on

First is the only way it's really off and not consuming power. If you only do a bit of midi magic the power consumption of the Arduino is probably smaller than the standby current of the power supply. Unless you didn't tell us about LED madness.

Talking about that, powering the Arduino from 9V via Vin/jack is fine as long as it's only the Arduino. It can't really supply more current then it need for the Arduino, so again, no led madness.
Use fricking code tags!!!!
I want x => I would like x, I need help => I would like help, Need fast => Go and pay someone to do the job...

NEW Library to make fading leds a piece of cake
https://github.com/septillion-git/FadeLed

Wawa

- Just leave it on
+1
A Mega only consumes 0.35watt, maybe 0.5watt including the cellphone charger.
Not worth unplugging it.
Leo..

masterheavy

thanx for the suggestions, and nope - no LED madness only some light to show which internal
controller bank is selected.

imagine the controller is in a rack - cables are on the back - no clutter on the front - can't reach powerstrip
switch.

having a multi-socket power strip with a foot switch for all the modules in the rack - another bad idea if
one would like to use only some of the modules and switch it ON and OFF if needed.

the rack could may be something like this...  - Rack example

but besides that "to power or not to power" dialogue, back to the basic question:

does the barreljack soldered on the pcb connect to the same ground as the rest?

I have a simplified picture - can one tell me if this is correct (hopefully one can see that all gnd of the
Mega are connected to the round plan...[and the switch is only a to visualize and get the plan correct])






septillion

With racks like that it's pretty common to just have a main switch. Like I said, if you don't cut the mains power to the USB charger there is no real benefit in turning off just the Arduino. Bit like disconnecting the hose without turning off the water. And that has nothing to do with the usefulness of a PCB (although I would argue a Mega seems a weird choice and a huge PCB like that is an even more weirder (aka, wayyyy to expensive) choice...). Making a PCB to have a clean design is a good idea.

But yeah, if you want to input power you need to connect both power and GND.
Use fricking code tags!!!!
I want x => I would like x, I need help => I would like help, Need fast => Go and pay someone to do the job...

NEW Library to make fading leds a piece of cake
https://github.com/septillion-git/FadeLed

Wawa

Is there nothing in your rack with a spare USB socket, to power the Mega from?

A schematic diagram of a Mega is available on the Arduino product pages, both in Eaglecad and in .pdf form.
There is a reverse protection diode between the DC socket and V-in on a Mega.

You seem to have connected the DC socket wrong.
On your layout, + (center pin) is the lower horizontal slot, GND is the top horizontal slot, and the vertical slot on the left is not used or can also be connected to ground.
Leo..


masterheavy

You seem to have connected the DC socket wrong.
On your layout, + (center pin) is the lower horizontal slot, GND is the top horizontal slot, and the vertical slot on the left is not used or can also be connected to ground.
Leo..
yeah thx, seems that the kicad power jack symbol is wrong.


Go Up