Pi2 in a Mega Drive 2 - advice needed

suprjami

Read about powered USB hubs, backpowering, and how to test for it here: http://elinux.org/RPi_Powered_USB_Hubs

Avoiding backpowering is still important with the Pi 3 as it has a 1.2A polyfuse on the USB ports. This is not a concern with a Pi Zero as it has no over-current protection anywhere.

The Mega Drive power adapter is 9~10V 0.8~1.2A: http://segaretro.org/AC_adaptor

If you wanted to use that, you would need to regulate down to 5V. You'd theoretically get about 1.5~2A or a little less out of it, but the power adapter is almost 30 years old, it will probably sag voltage to unsafe levels well before supplying full current. I strongly suggest using a good modern 5V power supply. You can use a power brick or power cable with a barrel jack if you wish.

Some existing projects:

http://www.instructables.com/id/Raspberry-Pi-Sega-Mega-DriveGenesis-II-Case/
http://retrorides.proboards.com/thread/131844
There was one on the old RetroPie Forum too, in the People's Projects section

Robocop

Thanks for the reply!

I see that my hub is listed on the page you linked as Verified as powering the Raspberry Pi. As I have a pi2 and not a 3 will it therefore be ok to backpower the Pi and will that give me the power I require to use Xbox 360 controllers, USB HDD and USB WLAN adaptor do you think? I noticed in the Instructables build they used an unpowered USB hub so would I be better off just using one of those, am I over complicating it for myself and worrying about power issues that won't exist (or maybe even creating some by backpowering)?

Sounds like the barrel jack idea with the original power supply is a bad idea so I'll forget that, maybe something for when I have got a lot more experience!

Thanks again.

R

Morph-X

Maybe i'm completely missing the point to your question, but would a powered USB hub even be necessary? I have a few builds (two of them based on the Pi 2 and one on the Pi 3), but for all four USB ports i use USB extension cables (so unpowered). I can not imagine controllers consuming that much energy, but i don't know for sure about the Xbox controller. I never had any issues regarding power, i just make sure i use a 3A micro USB power adapter (especially for the Pi 3). In my opinion (and i admit having limited knowledge about these things) an adequate adapter is really important and could potentially solve power-lack issues on its own.
On the other hand, you could ask yourself if a USB HDD is really necessary? Would a 16GB micro-SD card for example not be sufficient?

Good luck! And keep us posted on your project!

Robocop

@Morph-X

Thanks for the reply, I think maybe you're right and I'm trying to fix a lack of power problem that doesn't even exist. It sounds like it's going to be best to just get a good quality power supply. I'm going to order the parts today so hopefully will be able to make a start on this over the next couple of weeks. Thanks again to everyone who replied and obviously if anyone else has any suggestions please let me know! One thing I was thinking about doing was having the HDD (although I think a USB stick would be better actually) inside a cartridge and then having that plug in using the original cart socket on the MD2 so I'll get a broken cart off ebay and see if that is something I can manage! Obviously that would just be for the novelty factor I realise that's definitely not the best way to connect a USB stick!

backstander

@Robocop I wonder if you could use something like those Megadrive/Genesis Flash Cartridges as your storage. They are basically a Megadrive/Genesis cartridge with a MicroSD card reader for storage of ROMs. I don't know it it will work but just an idea!

Robocop

@backstander
Yeah that's definitely something to consider! I think I read on one of the SNES mods though someone saying that SD cards via the original cart slot can be tricky and USB is more tolerant of that type of connection. Still I'll definitely look into it. Thanks again.

cyperghost

The flash cartridge is a cool piece of work... sorry it's german but the flash cartridge seems to be very promising :)

Robocop

@cyperghost
Yeah those carts are great, I have a SD2SNES for my SNES which I use all the time but I haven't got around to getting one for my other (working) Mega Drive yet as they are quite expensive (if you buy a proper one rather than a chinese copy which are dubious as they have copied someone else's hardwork). There is definitely something special about playing all the games on original hardware and via a CRT but emulation is also very awesome in different ways!

spannernick1

I did this with a mega Drive and CD model 1,I think it looks better,I posted about on here.

spannernick1

The power supply I used is from a PS Vita work fine,but it has a notch in the usb connector slot and you need to file it down so you can fit a usb to mini usb cable.

I use as well a Mayflash USB MD adapter so I can use the original control pads.

Good luck with yours,hope this helps.

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Robocop

@spannernick1 said in Pi2 in a Mega Drive 2 - advice needed:

Mayflash USB MD adapter

Ah thank you! Yeah I also prefer the look of the MD1 but my MD1 is still working so would feel bad about using it. Same reason I haven't gone for a SNES as I only have a working one and the price of even broken retro consoles seems to have gone pretty high these days!

I hadn't heard about the Mayflash USB MD adapter but it's a very good idea, did you have any issues with that working with RetroPie on the various (8-bit and 16-bit) emulators?