Author Topic: Fun with raspberry pi  (Read 260 times)

keilmillerjr

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Fun with raspberry pi
« on: November 23, 2018, 10:46:03 AM »
RetroFlag MegaPi case
Raspberry Pi 3 b+
Case fan and heatsinks
Raspbian Lite 10/09/2018
Composite 240p for crt

Compiled mame 0.203
Attract 2.5.1

Will do testing soon. I’m having an issue with my psu and think it’s effecting performance greatly. Mame speed has been decreasing. Under voltage issue.
« Last Edit: November 23, 2018, 11:36:35 AM by keilmillerjr »

progets

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Re: Fun with raspberry pi
« Reply #1 on: November 23, 2018, 11:44:07 PM »
Just my 2 cents.

- 90%+ of heatsinks for for the Pi are trash and use stickers to attach which have zero thermal transfer
- a fan would introduce noise, and more importantly for you voltage and amperage draw on your Pi and power supply
- a Pi cost less than $40. forget about all heatsinks, fans and maybe even cases. overclock it to the max and if it dies (which it won't) buy another one with the $40 you saved on the heatsinks, fan and case.
- a Pi without a case will run cooler than one in a case. a case is really for portability and aesthetics.
- once you emulate on good hardware (which I know you have) the Pi is a nice toy but will never satisfy your expectations. it's a fun project but only if you're poor, not a serious emulator, only want really old games or need a super small footprint.
- the Pi emulation limitation is only part of the puzzle, these same limitations are placed on the AttractMode layouts

P.S. Keep in mind that any MPEG2 video decoding on the Pi is done by the CPU by default. If you buy the cheap MPEG2 license you can offload this to the GPU which will help a ton on performance and overall Pi temperatures. I doubt that most use MPEG2 videos on the Pi but it's worth pointing out.
« Last Edit: November 24, 2018, 09:34:38 AM by progets »

keilmillerjr

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Re: Fun with raspberry pi
« Reply #2 on: November 24, 2018, 10:51:58 AM »
Pi 3 b+ has no default overclock options. It’s just a fun project to see if I can run same romset as my arcade machine. As it stands, the pi is already better than these retro consoles (my opinion) because it has composite out. I don’t expect it to be perfect. I don’t even play video games. Just like the hobby. Arcade reminds me of time with my father as a kid.

FrizzleFried

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Re: Fun with raspberry pi
« Reply #3 on: November 29, 2018, 07:24:18 AM »
Pi 3 b+ has no default overclock options. It’s just a fun project to see if I can run same romset as my arcade machine. As it stands, the pi is already better than these retro consoles (my opinion) because it has composite out. I don’t expect it to be perfect. I don’t even play video games. Just like the hobby. Arcade reminds me of time with my father as a kid.

I am not sure if I am picking up what you're putting down correctly, but yes,  you can overclock the Pi3+... I'm running mine at 1475mhz but more importantly I'm overclocking the core/gpu, etc to 550mhz. 

Also,  I agree that you should never use the supplied sticky crap with any heatsink... I have a tube of thermal epoxy here for just such cases.  Prior to the HSF I could only overclock to 1450 stable... with it I'm at 1475 rock stable... 1485 will run for hours but did crash once so I pulled back a hair.   Sure... 25mhz aint much,  but it's something... and it's fun to tinker. 

For the fan,  I simply attached a 12v 40mm fan mounted via a PCB standoff blowing across the epoxied heatsink...

As for noise... it's nearly dead-quiet ... and when I close the control panel you can't hear it at all.

As for power consumption,  my Pi is in an arcade cabinet and I'm pulling the 12v from the much much overkill arcade power supply.

:)

Visit my arcade blog ... www.idahogaragecade.com (updated 12-13-18)

keilmillerjr

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Re: Fun with raspberry pi
« Reply #4 on: December 02, 2018, 05:38:38 AM »
New power supply arrived. No more under voltage issues. Results are now consistent and reliable.

Mame0203b
Code: [Select]
$ ./mame mslug -str90 -nothrottleAverage speed: 74.36% (89 seconds)

advancedMAME 3.9. It’s based off MAME 0.106.
Code: [Select]
$ advmame mslug -misc_timetorun 90Yields 42.476 seconds. This would be the equivalent to 212%.

I am not using SDL for advancemame. When launching from terminal, docs says it uses the linux framebuffer. What is interesting is that my results with mame 0.203 is about half of the choccyhobnob’s benchmark results, which was taken when 0.176 was out. Could mame have differed that much since? Perhaps there is some settings I am not aware of to speed things up? I am happy advmame runs fast.

keilmillerjr

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Re: Fun with raspberry pi
« Reply #5 on: Yesterday at 07:32:02 PM »
I worked a little bit on this today.

Modifying the retroflag script to close advmame, which should return to attractmode.

Autologin as pi user. I have a cron task to autoload attract. Works fine.

I had to specify a rompath as advmame keeps config files separate of binary. I have a romlist including my bios. Not sure how to get rid of bios (without manually editing the rom list). Also, selecting a rom causes weird shit to happen. Displayed quickly looks like crontab in nano and then focus back to attract. Sometimes it will reboot. If I launch attract without using crontab it launches as mame just fine. Hmm…?
« Last Edit: Yesterday at 08:09:51 PM by keilmillerjr »