Ok let's talk seriously about a MiSTer handheld...

[dot-bob]

I have been mulling over the idea of doing quality mister handheld for a while now. I have see a couple of designs pop up but nothing that is easily accessible to the community. I have done couple different mister handhelds so far with off the shelf parts and a 3d printed case but so far I haven't been completely satisfied with the outcome. This is primarily due to the height with the SDRAM board, fan and cabling.

So far here is a short list of my desired features:
HDMI output
USB C charging
Internal USB port (for Bluetooth or WiFi Dongle)
SNAC Input (with built in level shifting)
Onboard RAM (to reduce board height)
Option for passive cooling

I tossed a couple of rough 3d models together to help determine the feasibility of the ideas. Most of the components are just hand placed at the moment so if you see something misaligned it probably is. Any of the USB connectors could be changed to a 3.0 connector to support SNAC. There will still need to be PCB's added for the controls / buttons, leds indicators, and speakers. The Display is probably going to be the major driving factor in the design. Do we use a HDMI display, VGA, or modify the code to drive a display directly. I am thinking of using a small pcb to connect both usb and or HDMI to the bottom board.

The first model is the DMG styled handheld. I have sized the model off of a Gameboy DMG. The outside dimensions of width and thickness closely match the DMG other than I needed to add 12mm in height to get a dual 18650 battery holder to fit in the design. Currently I have the DE-10 Nano slid all the way to the edge which would allow access to the DE-10 nano SD card and HDMI connector but will change the corner radius. The display cutout is currently sized for the same 5" VGA (640x480) display currently being used in the G-boy handheld from BitBilt.

The second model is a hand held in what I call the wide format. It is sized slightly smaller then the nintendo switch but the same thickness of the DMG handheld. The RJ-45 ethernet connector could be left unstuffed and the hole removed from the case for those who don't want it. I placed two HDMI connectors at the bottom to thinking to use with bliss-box cables for SNAC. I don't know how worthwhile this would be. I am also toying with the idea to throw on a cypress psoc 5 and a button to allow someone to switch these ports from USB to SNAC. The psoc could also allow analog i/o and level shifting for other future ideas. If designed correctly the main board may also be used as a compact usb C powered mister console. The display in the model is a 5.5" V2 amoled display from waveshare I am experimenting with.


This thread is primarily to come up with idea's and let the community help drive these designs. The designs will be opensource but not necessarily created with opensource tools. While I have resources to produce the design commercially I really have no desire to do so. I do this type of stuff every day at work, and coming home doing the same I will quickly loose interest. I don't expect the project to go very fast as the time I have to contribute will vary week by week.


With that said what handheld format do people prefer? And is there any other features / options / ideas /changes you would like to see?

[Newsdee]

You would probably need to create an all-integrated PCB with RAM and I/O in order to fit a case as flatly as possible. It could even have integrated LCD instead of VGA output.

The HDMI output could be a pass-through to the external case, and allow enough space to plug the DC power jack on the DE10. I have a short "CEC removal" dongle that could fit for this (it protrudes about 2 cm from the DE10). The caveat is those are niche products and keeping a good supply can be an issue. But maybe they can be custom made, after all this dongle is just cutting off a pin to prevent CEC from interfering with video out.

[chanunnaki]

Ultimately, if I were to invest in a MiSTer handheld, I would want it to be in the dream resolution of 1600x1440 resolution like the analogue pocket. That is only a 3.5" display, but I personally think that's big enough for a handheld and more space could be dedicated to front-facing stereo speakers.

This display is available on AliExpress here: [https://www.aliexpress.com/item/4000505 ... web201603_] and costs €69/$80. It has two break out boards though, which would make integration into a handheld difficult.

I like both the DMG and horizontal form factor but a little more partial to the horizontal style.

[chanunnaki]

ETA Prime on YT did a video on the Wavshare AMOLED and he had terrible luck with it; getting tonnes of screen tearing, albeit with a Raspberry Pi which suffers terribly with screen tearing regularly.

[amadama]

I've been trying to work on a handheld Mister for over a year. I've researched and purchased so many of those small screen. I really thought the AMOLED screen was going to be a winner, but unfortunately it's not 1920x1080, it's 1080x1920. It doesn't display the Mister screen at all.

The best I've found was a 5" 4:3 aspect ratio screen with 640x480 resolution (I can't deal with the 3.5" screens, I'm too old and my eyesight not great anymore).

https://www.amazon.com/dp/B07QC6YS8L

I really like both of the OP's designs but am partial to the horizontal layout (particularly if using a 5" screen.)
My design (only on paper) was similar to that one, but had a large bulge in the back to accommodate the mister with SDRAM board and all the electronics for the LCD (2 or 3 boards). The bulge does not extend to the sides where the controllers and buttons would be so holding it would still be comfortable.

A custom add-on board would be the cleanest way to integrate the Mister into a handheld, there are too many supporting boards required otherwise and the device ends up being too big.

I still want to do this so if I can help in any way count me in.

[redsteakraw]

controls wise are you going for a 4 or 6 button layout. Personally the 6 button layout with shoulders is the most versitile from arcade to console to handheld. the 8Bitdo m30 is the gold standard with start, select and home. Can play GBA just fine and SNES, then switch to Genesis, it is awesome to play 3 button Genesis games without compromise and 3 button TurbografX. Playing 3 button games on a 4 button diamond just doesn't work well. Playing 6 button designed games on a 4 button + shoulder based controller feels weird as well. But a 6 button layout done right can still have a 4 button diamond that also feels right.

[Newsdee]

Playing 6 button designed games on a 4 button + shoulder based controller feels weird as well.

Not if you grew up with a SNES and SF2

[MiSTer_Kirk]

Don't see the point in a Mister handheld. Surely the point of getting a Mister is to be able to connect it to a CRT, or a modern LCD, then use a keyboard, mouse, and decent joystick, and to get a closer feel to the original hardware. In a handheld, is there any reason for such accuracy ?
Wouldn't a Pi 4 handheld be better, and cheaper ?
Why not just get one of these ?
https://www.experimentalpi.com/PiBoy-DM ... _p_18.html

I have a Waveshare Raspberry Pi Game HAT + Pi 3b+, and in a handheld it's perfect.

[deltax0]

That OLED looks nice.
There prob going to have some options for handheld i bet in the future.
I just hope for quality parts. long battery, epic screen. nice buttons and joysticks. allow for ram.

[FoxbatStargazer]

Don't see the point in a Mister handheld. Surely the point of getting a Mister is to be able to connect it to a CRT, or a modern LCD, then use a keyboard, mouse, and decent joystick, and to get a closer feel to the original hardware. In a handheld, is there any reason for such accuracy ?
Wouldn't a Pi 4 handheld be better, and cheaper ?
Why not just get one of these ?
https://www.experimentalpi.com/PiBoy-DM ... _p_18.html

I have a Waveshare Raspberry Pi Game HAT + Pi 3b+, and in a handheld it's perfect.

We're talking about "modern LCDs" in a handheld too. On a system that can already run some handheld cores and is getting more over time! This would be the most authentic way to replicate gameboy/color/advance, game gear, and soon lynx, maybe wonderswan and neo geo pocket down the road, not to mention portable conversions such as turbo express and nomad, or the game gear's master system support. Or you could play home consoles and computers on the go for convenience, just as handhelds received conversions of home games all the time, now you don't have to wait for the conversion.

Input lag is still an issue with handheld emulation, and even with things like Nintendo's backwards compatability, GBA/DS games run with ~2 frames of additional lag on 3DS hardware. You can feel the difference swinging link's sword or making those precision Mario jumps. It gets worse if you are forced to run some of these underpowered chipsets with threaded rendering and the like. Then of course there's audio which always lags significantly on software emulation and tends to suffer micro-adjustments to resync with video, not to mention that accurate low-level emulation is typically not so viable on these low powered chipsets.

If those sorts of difference bothers you with emulation on a TV there's no reason it wouldn't bother other people when playing handheld for the exact same reasons. If you're fine with a cheap handheld for a cheap handheld experience that is great, but there are others who would pay more for a premium handheld experience, as the analogue pocket instantly selling out should make clear.

[MiSTer_Kirk]

If those sorts of difference bothers you with emulation on a TV there's no reason it wouldn't bother other people when playing handheld for the exact same reasons. If you're fine with a cheap handheld for a cheap handheld experience that is great, but there are others who would pay more for a premium handheld experience, as the analogue pocket instantly selling out should make clear.

To be honest, I own and prefer the real thing when it comes to handhelds. For Gameboy + Colour + GBA, I own original machines but with modern screens, and the original DMG Gameboy with a modern IPS backlit screen looks amazing.
And for the record, a Raspberry Pi 4, in one of those Piboy DMG cases, is not a cheap experience, it's extremely close to the real thing. the Pi 4 handles all those 8-bit and 16bit machines with ease. You can do things the Mister can't do such as portable System 16 Sega Arcade games like Outrun, Space Harrier, all run fullspeed on the Pi 4. Mame2003Plus, with a full rom set is miles ahead of the Mister for the availability of arcade games, even if it ain't as close as accuracy as the Mister.
I wish the project all the best. But if it doesn't come to fruition then don't rule out the Pi way - You can even carry around a mini Rii blue-tooth keyboard and play computer systems on the Pi. And because the Rii has a rubber keyboard it feels like a mini ZX Spectrum.

[aberu]

ETA Prime on YT did a video on the Wavshare AMOLED and he had terrible luck with it; getting tonnes of screen tearing, albeit with a Raspberry Pi which suffers terribly with screen tearing regularly.

Raspberry pi 4 tears on just about anything I hook it up to. Not great for reviewing an lcd

[dot-bob]

ETA Prime on YT did a video on the Wavshare AMOLED and he had terrible luck with it; getting tonnes of screen tearing, albeit with a Raspberry Pi which suffers terribly with screen tearing regularly.

The display I have been playing with is the Version 2 of the amoled display which I originally bought it for another project. I have it working with the DE-10 nano but it is a bit finnicky. The availability of the display is also seems a bit questionable. The product page I purchased it from is gone and the documentation isn't listed on waveshare's product pages.

The display I use on my current mister handheld is the one listed here: https://www.amazon.com/gp/product/B07S51QDTG. It seems to work pretty good and runs ok with vsync_adjust=2 with the occasional resync due to frequency changes. Using the time sleuth display lag is around 2-3ms which is as good as any HDMI monitor I have tested. It also has build in stereo speakers.

[dot-bob]

You would probably need to create an all-integrated PCB with RAM and I/O in order to fit a case as flatly as possible. It could even have integrated LCD instead of VGA output.

The HDMI output could be a pass-through to the external case, and allow enough space to plug the DC power jack on the DE10. I have a short "CEC removal" dongle that could fit for this (it protrudes about 2 cm from the DE10). The caveat is those are niche products and keeping a good supply can be an issue. But maybe they can be custom made, after all this dongle is just cutting off a pin to prevent CEC from interfering with video out.

If we choose an HDMI display I was thinking of using something like the TI TS3DV642 and mux the HDMI video to either the internal display or external facing HDMI connector.

I'm thinking of covering the DC power jack and powering the board from the IO header. This way we don't need to deal with the large connector and any voltage drop from the voltage protection circuit. I need to find a good chip that can take advantage of USB power delivery and charging 2s lithium ion cells. Then switch the voltage down to 5V and input it into the DE-10 I/O header.

[Newsdee]

Is there any component that could take a 12V input, but output a 12V and 5V outputs?

That would be handy for arcade modding projects that require 12V for the display and audio amp, but 5V for the rest.
On a big arcade I could just use 2 power bricks (and a relay to only activate the 12V devices when the 5V are powered), but there must be a better way to do it. I suppose amperage could be an issue with a single power input, though (versus a PSU that gives both 5V and 12V from AC power).

[Newsdee]

Found the answer in another thread... there are cheap buck converters that can take 12V and outout standard USB 5V... that would seems to do the trick. I'll have to try.

As for HDMI, I suppose it depends on the LCD. Using VGA might be easier but you would be sacrificing resolution. It would still allow external HDMI to play on a bigger display, thoigh.

[retrorepair]

Ultimately, if I were to invest in a MiSTer handheld, I would want it to be in the dream resolution of 1600x1440 resolution like the analogue pocket. That is only a 3.5" display, but I personally think that's big enough for a handheld and more space could be dedicated to front-facing stereo speakers.

This display is available on AliExpress here: [https://www.aliexpress.com/item/4000505 ... web201603_] and costs €69/$80. It has two break out boards though, which would make integration into a handheld difficult.

I like both the DMG and horizontal form factor but a little more partial to the horizontal style.

Can MiSTer output 1600x1440?

[chanunnaki]

Ultimately, if I were to invest in a MiSTer handheld, I would want it to be in the dream resolution of 1600x1440 resolution like the analogue pocket. That is only a 3.5" display, but I personally think that's big enough for a handheld and more space could be dedicated to front-facing stereo speakers.

This display is available on AliExpress here: [https://www.aliexpress.com/item/4000505 ... web201603_] and costs €69/$80. It has two break out boards though, which would make integration into a handheld difficult.

I like both the DMG and horizontal form factor but a little more partial to the horizontal style.

Can MiSTer output 1600x1440?

Yes.

It's capable of 2048x1536, so 1600x1440 should be possible. I haven't tested it myself, mind.

[Newsdee]

Can MiSTer output 1600x1440?

I use 1720x1440 on one of my monitors, so, yes.

[dot-bob]

A vendor stopped by work and dropped off a few displays for me to try out... It's a bit overkill and I haven't measured the display lag of the provided hdmi to mipi board but here are some pics of MiSTer with the 1440x1600 display.

1440x1600 Display.jpg (1.97 MiB) Viewed 3646 times

1440x1600 Mario.jpg (2.02 MiB) Viewed 3646 times

[retrorepair]

I think this is the exact LCD I was looking at The MIPI board should have very low latency as the driver IC is used widely in VR headsets.

Shame you didn't test the Gameboy core, I'd have been interested to see that but I believe this is the exact same panel Analog are using for their pocket.

Either way I'll be acquiring one of these for testing

[jandrogo]

How many inches is that screen?

[elJonnyRage]

I think this is an awesome idea and I would love to see it come to life. I bet you could even get crowd funding for it. However, I think that 3.5 inch would be a great form factor for all of the handheld games, but thinking about the bigger picture I think that something like a 5.5 or 6 inch display would be much better for an all around portable MiSTer. Having built in controls with an available usb port or two for peripherals and the HDMI out exposed for docking/connecting to a larger screen. So if you could only go for one I would say the larger screen is the way to go, but it might be cool to have two models (similar to another company) except for both could connect to a larger Monitor using HDMI out. This would be the ultimate Retro Handheld. So exciting to think about!

[BlackSpy]

Handheld is nice, I'd be interested to see a Mister built into a fight stick too. let it daisy chain a second controller.

[reminon]

I love this! Even if it were to be built into a wiiu gamepad, a handheld would be amazing. I would throw a few hundred into it