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Forum Index : Microcontroller and PC projects : PicoMite: PicoGAME VGA development
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| Volhout Guru  Joined: 05/03/2018 Location: NetherlandsPosts: 4262 |
Is this the home brew game paddle with the 4021 chip? I did some test with it, you can SPI it at 1Mhz. Look at the old thread. I remember Tom sayong he was happy with his mmbasic read routine.But SPI was faster. Edited 2022-06-20 01:58 by Volhout PicomiteVGA PETSCII ROBOTS |
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Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6821 |
Yep, that's the one. I bet the GP pins I've used don't work out anything like for SPI. lol Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4262 |
Connector K8 has the exact pinning for the NES controller that Tom specified in his earliest post in this thread. Not sure however if the gender of this connector is the correct one. So you can use SPI to read the NES controller. I will try to breadboard one, and see if it works later this week Volhout Edited 2022-06-20 06:02 by Volhout PicomiteVGA PETSCII ROBOTS |
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thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4047 |
You are late to the party @Volhout, the A & B controller ports are pinned and gendered (assuming I sent you the correct parts, should be male on the PCB and female on the controller) for NES/Famicom clone controllers. @Mixtel90 humoured me in this eccentric controller choice (rather than using I2C nunchuck ports) and it is tested and working. Here's a message I was penning at the same time as you: Hi Volhout, You are referring to this thread: https://www.thebackshed.com/forum/ViewTopic.php?TID=13907 1. The PicoGAME can take two NES/Famicom style controllers with 9-pin D-subs. - it can alternatively take Atari style digital joysticks (only 1 on the v1.4 board but 2 on Mick's current experimental boards) - there are also analogue control options, but there is no off the shelf new controller that is compatible with those you have to home-brew and I am largely ignoring them. 2. The NES/Famicom controller is a standard design based around a 4021 shift-register and some resistors - commercial ones have an epoxy blob rather than discrete components. - the official NES controllers use a non-standard 7-pin (?) connector but clone devices use 9-pin D-subs, I think the original Japanese Famicom actually hardwires the controllers to the base unit. 3. I built my own compatible controller on perfboard using discrete components and discussed it in that earlier thread. 4. You can buy compatible controllers for peanuts off AliExpress, e.g. https://www.aliexpress.com/item/32919127872.html - make sure they have a 9-pin D-sub not the 7-pin connector (though these can easily be hacked) or USB (more expensive and not so easy to hack I imagine). - you can likewise buy Atari joysticks, e.g. https://www.aliexpress.com/item/1005003590552924.html 5. My understanding is that the protocol with these controllers is close to, but not identical to SPI (I suspect it may predate standardisation of SPI). - some of the signals are inverted c.f. SPI so I don't know if the 'mite firmware SPI commands can handle them, I have been assuming they will need bit-banging, and have previously posted code to do so. 6. I have recently discovered that it may be possible to get SNES style gamepads working on the PicoGAME too, these have an extra 4 independent fire buttons and as I understand it basically just use two shift registers hooked together to give 16-bits but otherwise use the same protocol as the NES controllers. @Mixtel90 how would you feel about me starting a FAQ on the PicoGAME (and controllers) on my github pages, I think this about the 3rd time I've described them in one way or another. Best wishes, Tom Edited 2022-06-20 07:03 by thwill Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4262 |
Tom, Thank you for the update. Nothing new afaik. I brought this up because I did prototype the 4021 before, and used SPI to read it. You mentioned th bit bang of the controller took more time than you had available. So I wanted to see if SPI would give you the performance gain. But spi can only work on k8, not k7 PicomiteVGA PETSCII ROBOTS |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6821 |
Yeah, no problem. :) TBH I don't think there'll be any possibility of making the controller ports hardware SPI. One has to share with the SD card, some pins for the other are already used for the VGA. It would - even if pins are available - probably be a complete re-hash. The only other possibility would be to bit-bang the existing pins as software SPI. As there is no CS signal, I don't see a way of putting both controllers on the same SPI without additional gating (no board space) - and all the GP pins on the Pico are currently used (except the LED output!). I've not had time to look into this deeply yet, so things *may* change - but don't hold your breath. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4047 |
I would leave it be. Judging the MMBasic Challenge 2022 not withstanding I should get the first 2-player (but not serial link) PicoGAME game with support for NES-style and Atari controllers running within the month and then I'll know one way or another if the controllers can be bit-banged fast enough (whilst doing all the other things that a game needs to do) in MMBasic, I suspect they can, I was just confusing my milliseconds with my microseconds. Best wishes, Tom Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4262 |
Tom, If I get my own NES controllers working (I got the parts, but need to put them on perf board) I will try to make the PIO block read then and present the data in the PIO FIFO's. In the game you just need to read an unsigned char (byte) PIO READ 1,0,a%() I am thinking about having one PIO1 sequencer read both controllers -or alternatively- use 2 identical PIO1 sequencers, one for each controller. The latter has the advantage you ca start stop each controller independently, allowing a mix of controllers, but might fill almost whole PIO1 memory. So nothing can be added anymore. Regards, Volhout Edited 2022-06-20 16:25 by Volhout PicomiteVGA PETSCII ROBOTS |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4047 |
That would be great, but no obligation. If necessary, and in time I will figure it out for myself. I think you do need to read the controllers independently because one of the ports may have an Atari joystick or null modem cable plugged into it instead of a controller. I'm of the opinion that doesn't matter for the intended purpose of the PicoGAME, if you've got two NES style controllers attached then there are no pins/ports remaining on which you might want to do I/O. Best wishes, Tom Edited 2022-06-20 19:36 by thwill Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6821 |
I couldn't resist - and started playing again. :) The PicoGAME Mini In Chinese plastic box 90x70x28 (black and white are available on ebay for around 3 UKP) Only Port A is used (uses the same GP pins as the PicoGame and has same capabilities) Micro SD surface mount socket (uses the same GP pins as the PicoGame) Simplified VGA circuit No fancy stuff like wireless, COM port or RTC (at the moment anyway) Not decided on power - may just use the USB on the PicoMite. Audio will depend on what I can fit in when I get to it. :) At the moment it uses the larger VGA socket as it's easier to get in the UK, but this may change if I need the board space. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3154 |
I'd be interested in this one when you have the gerbers ready. Can you provide a link to the box? I'm trying several non-VGA designs, and would try to standardize on an inexpensive box if suitable. PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6821 |
There seem to be several suppliers on ebay (example) and possibly from other sources too. Oh, it was about 3 UKP for 2 boxes, not one. :) Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3154 |
Nice box. I like that the ends are removeable and could be replaced with PCB panels. I've spent a lot of time the past week looking at boxes. I've just now decided to go with this one: 140x82x38mm (Admittedly not best suited for your mini PicoMiteVGA PCB.) ~ Edited 2022-06-20 22:33 by lizby PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4262 |
Hi Mick, Can you please share the schematics for the 1.4 board. I first started my NES controller, and could not map the pins to the pico. Honestly, I have no idea how the wiring on the board is. I am not even sure if the Famicon wiring Tom presented is correct. Totally confused.... No 3.3V at K8, no transistor to switch voltage at 3.3V. No 68 ohm and e-cap. Is it directly powered from an IO pin ? Volhout PicomiteVGA PETSCII ROBOTS |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6821 |
Is it a blue 1.4 or one of the red prototype boards? That would be confusing. :) The 1.4 info is in the constructors pack here. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4047 |
Hey, I may know nothing, but I do know how to wire an NES/Famicom controller, I've done it often enough  .I believe these are the two diagrams I based my work on: - https://i.imgur.com/WJWXULt.png - https://www.allaboutcircuits.com/uploads/articles/nes-controller-arduino.png?v=1469416980041; though I may have used 10K pull-ups and driven them at 3.3V as well as 5V - but never both at the same time  .And I have tested and compared both breadboard, perfboard and real hardware versions (2 different manufacturers). This of course may all be "famous last words", Tom Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4262 |
I was confused. I had my controller wired up like Tom example at the start of this thread. Looked at the schematics that where published as graphics on page 2 of this thread, and could not get it to work. Started measuring the board, and discovered GP0 was at pin 1 of K8, not pin 4. So my wiring was all mixed up. I think the original wiring on page 2 of the thread allowed SPI of the 4021. I rewired the DB9 cable, and now it works (bitbanging, and potentially SPI), but the connections are not anymore compatible with Tom's. So now I have to go back and rewire again to Tom's pinout. And find the new pin numbers from Mick schematics. And not use SPI, since that does not match anymore. The early schematics took SPI into account I realize, but the newer ones (1.4) do not. Volhout PicomiteVGA PETSCII ROBOTS |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4262 |
Hi Mick, Tom, Now I look at the 1.4 schematics, I am not sure I will be able to write PIO code for K7. The PIO IO ranges should be consecutive. For K8 the range for NES (clock, latch, data) is GP1...GP3. For K7 that range is GP4,5,22. Not sure if I can fit the GP22 in the same sequencer as GP4 and 5. Have to study. Maybe it will, since the IN range (shift IN) is needed for the DATA pin (GP22) can be different from the SET range (GP4, GP5) and the SIDE SET range. Volhout Edited 2022-06-21 06:09 by Volhout PicomiteVGA PETSCII ROBOTS |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6821 |
The prototype didn't take SPI into account - it was just the way the connections worked out. :) Version 1.4 swapped over the ports (among other things), leading to changes in the GP pins used. ------------------- PicoGAME VGA Mini I decided not to surface mount the PicoMite as I can use the space underneath it. Unfortunately that means that if you use the recommended box you can't connect to the USB socket without opening the box, so it's back to the barrel jack for power. I don't mind removing the lid for firmware updates, that's fair enough. The micro SDcard socket is surface-mounted, so a bit of fiddly soldering there. The audio socket is also surface mounted, but that's easy to solder. I think I've got the layout sorted out now, but I still need to finish the virtual testing. Still doing a bit of tidying up. Not sure about whether to put a linear reg in - space is tight. If I do i will probably have to be compulsory, not an option. I've squeezed your inductive filter in, Volhout, providing that the Farnell inductors are used. I need to sort out the case end panels, which will come as part of the PCB. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4047 |
Hi Volhout, Any SPI you might see is purely a figment of your own imagination and/or coincidence. I think you are ironically being hampered by your own expertise and expectations. This controller design is 40 years old and I do not believe was ever intended to be SPI compatible; I've read about a fair number of homebrew projects using this controller none of which have talked about using SPI. If Wikipedia is to believed the Famicom was released by Nintendo (1983) at about the same time that Motorola was creating the SPI standard (1979 or mid-80s are both quoted). If it can't be done then it can't be done ... or Mick will fiddle the PCB again, but I suggest we wait to see what I can achieve by bit-banging in BASIC or failing that a CSUB. Best wishes, Tom Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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