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Forum Index : Microcontroller and PC projects : PicoMite: Another option for VGA
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| matherp Guru  Joined: 11/12/2012 Location: United KingdomPosts: 10582 |
PicoMite.zip Attached is a PicoMite version for the RP2350 - note this is standard Picomite NOT vga. It now supports two new drivers: VGA222 and VGA222_320. These are enabled with: OPTION LCDPANEL VGA222/VGA222_320, hsyncpin, bluelpin This checks for availability of hysyncpin and hysyncpin+1 (vsync) bluelpin - bluelpin+5 (blue_l, blue_h, green_l, green_h, red_l, red_h assuming these are all free it sets up to run VGA222 output on the pins specified in either 640x480 (VGA222) or 320x240 (VGA222_320) To connect the data pins to the VGA connector use 390 and 820 ohm resistors from the outputs as per the green channel in the manual ( page 29) RGB222 gives a much nicer colour rendition than the RGB121 available on the VGA version. Note, there are no modes. The 640x480 and 320x240 are different drivers and use different amounts of memory (much more in the case of 640x480). To generate the VGA output I use PIO0 and PIO1 leaving PIO2 available (unless you also use the I2S audio driver. The implementation of the drivers is pretty complete other than having specific RGB222 dithering available (tomorrow) I've tested running Petscii robots on the 320x240 driver and it runs superbly Do have a play and report any issues. Edited 2025-11-11 08:45 by matherp |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 5464 |
Hi Peter, Loaded this firmware onto the Game*Mite, and used the same wiring harness from keyboard pins to VGA connectors that worked before. OPTION LCDPANEL VGA222,GP8,GP10 and also tested OPTION LCDPANEL VGA222_320,GP8,GP10 I noticed the CPU speed is 352MHz (not 252MHz). But there is nothing. If I look with a scope at the HSYNC and VSYNC pins, there is no signal. Neither the RGB pins. This worked with the basic version. Using a genuine pico2 (RP2350A), not a pico2_plus (that uses RP2350B). Regards, Volhout Edited 2025-11-11 17:19 by Volhout PicomiteVGA PETSCII ROBOTS |
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| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 10582 |
Try OPTION RESET and then OPTION PICO OFF, then OPTION LCDPANEL VGA222, GP8,GP10, nothing else. Just tried this with a virgin RP2350 on a VGA DESIGN 2 using GP16,GP18 and it works perfectly with the uf2 from the ZIP |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 5464 |
Yes, that did it. But it is kind of strange since I nuked flash before I installed. VGA222 on 640x480 is great, but leaves only 134k RAM. So framebuffers cannot exists in RP2350. Nice for a photo frame, or as a "static" display. VGA222_320 (320x240) indeed offer far better presentation as the RGB121. Tested by loading JPG's on it. With a framebuffer size < 60kbyte, on a 2350 you could have framebuffers in 222 format, and still have a decent amount of memory to write programs in. Without framebuffers there is 314k RAM free in 320 mode. VGA222 is a nice addition. Too bad it is 2350 only. But when you can make it backward compatible with 121, we could still run the old programs. And the logic analyzer/chess client would not have to use tiles to produce color. But most for this already existed in HDMI right ? Volhout P.S. in 2350 you should also be able to use the HSTX block for VGA222, in stead of PIO's. There is code available for that. Not sure how mature though. Edited 2025-11-11 19:37 by Volhout PicomiteVGA PETSCII ROBOTS |
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javavi Guru Joined: 01/10/2023 Location: UkrainePosts: 521 |
 https://www.breatharian.eu/hw/disphstx/index_en.html |
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