Hello forum,
First of thank you for reading the post. Now, my project consist of creating a mini video game console with a couple of emulators from different old retro game consoles. The machine has a Raspberry Pi 3 model B and a 2.5 external HDD (USB 3.0) connected to the Pie via regular USB. The software used is called "Retropie".
I powered the whole thing using a AC/DC 5v 2a power supply and while everything runs OK I had some issues while testing Play Station 1 games (which requires more hard drive usage). Googling around I read that could be an amp problem so I bought a 5v 3a power supply (which I attached a female USB connector since it didn't have any) and I had more issues than before: the Pie tells me every time there is an undervoltage issue by displaying a little thunderbolt icon on the software I am using (retropie)... with the last power supply not only the icon displayed every time but it also took a lot more time to boot up.
So, how can I make sure that there is enough "power" for the HDD all the time?
Please, excuse my english.
Thank you for the time

 

Welcome to AAC!

It could be a problem with voltage drop in the USB cable. The wire gauge in USB2 cables only need to be sized to handle 500mA with less than a half volt drop.

 

Welcome to AAC!

It could be a problem with voltage drop in the USB cable. The wire gauge in USB2 cables only need to be sized to handle 500mA with less than a half volt drop.

Hi, thank you!
OK so that means I should consider using a "thicker" wire? How can I test that?
I'm sorry about that question, I am a bit new at electronics.

 

You can measure the voltage on the Pi under load. A DVM might be able to show a voltage drop, but an oscilloscope would be better.

You could also try using a high quality cable. For example, one from a tablet or similar device that abuses the USB spec.

 

You can measure the voltage on the Pi under load. A DVM might be able to show a voltage drop, but an oscilloscope would be better.

You could also try using a high quality cable. For example, one from a tablet or similar device that abuses the USB spec.

Will do and i will report back with the results. Thank you!

 

I would go with a powered usb hub for the hard drive.

 

Well, seems that a short micro USB to power did the trick. I tried a short micro USB cable I have (one from an old garmin... for charging) and I can now power the Pi directly and use its USB to power the HDD without any problem. It looks like I had some Voltage drop using long cheap cables.
By the way, i am using a 5v 2a power supply for the Pi and the HDD all together
Thank you guys!

 

Still need to get myself a voltage and amperage measuring tool

 

Welcome to AAC!

It could be a problem with voltage drop in the USB cable. The wire gauge in USB2 cables only need to be sized to handle 500mA with less than a half volt drop.

My USB external HDD has a special cable with 2 USB connectors to get enough current.

Its small enough to be a 2.5" HDD.