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Forum Index : Microcontroller and PC projects : DuinoMite and Colour?
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donmck Guru  Joined: 09/06/2011 Location: AustraliaPosts: 1313 |
DuinoMite and Colour? I believe that the hardware modifications that need to be done on a DuinoMite board may be easily achievable, because of what Olimex have done with VGA connector on their boards at pins 1, 2, and 3. This is applicable to all versions of DuinoMite. See the picture at: http://priuschat.com/attachments/duinomite-mega-pcb-vga-sign al-mod-png.41246/ for closer detail. A couple of reference links: http://www.quantenbit.de/#/teach/Technical/electronics http://www.thebackshed.com/forum/forum_posts.asp?TID=4964&PN =0&TPN=3 Please note that two normally unused pins on the programming header (pins 4 and 5) can be swapped for other I/O signals if need be. This message is to promote a thread, and draw a conclusion on the subject of "DuinoMite and Colour". Don... https://www.dontronics.com |
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jebz Regular Member  Joined: 13/06/2011 Location: AustraliaPosts: 79 |
http://www.quantenbit.de/#/teach/Technical/electronics Pin32 on this schematic is used for RED VGA video and the SD card data. |
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| donmck Guru Joined: 09/06/2011 Location: AustraliaPosts: 1313 |
Yes I knew there was a conflict with the SD card. That is why I suggested the two unused pins. I hope Geoff is in a position to say if a simple alternative is workable or not. Don... https://www.dontronics.com |
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bigmik Guru Joined: 20/06/2011 Location: AustraliaPosts: 2914 |
I think Jebz was mentioning that the circuit at Quantenbit is WRONG it puports to be a modified Maximite (built from a futurelec adapter) but the schematic changes are not correct as it shows Pin 32 in 2 places.. You are talking about a DM modification... along the lines of what Quantenbit has done for the MM regards, Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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| donmck Guru Joined: 09/06/2011 Location: AustraliaPosts: 1313 |
After reading a little more, I think the real conflict with doing a colour mod on a 64 pin chip is the shortage of SPI channels. The 100 pinner makes it workable and without the VGA problems. Would this mean the DuinoMite-eMEGA 100 pin (ethernet), would be a better match? http://www.dontronics-shop.com/olimex-duinomite-emega-ethern et.html Also it has no shared pins. Don... https://www.dontronics.com |
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Geoffg Guru Joined: 06/06/2011 Location: AustraliaPosts: 3194 |
The issue with modifying the MM was that the copper track joining the red/green/blue pins on the VGA connector was under the connector. Removing the connector (to cut the tracks) would probably damage the board because it uses plated through holes which makes it VERY hard to remove anything after it has been soldered in. I never realised that the DM is much easier to mod (the tracks are easy to get to). The other issue with modifying the old design is that there are only 3 SPI channels (as noted by Don). Kilian Singer got around this by paralleling the red signal with the SD card signals and this required the red video to be disabled when data was written/read from the SD card. The result was a flickering on the screen whenever the SD card was accessed. This was was annoying but you could get used to it. When I started on the Colour Maximite I had two choices; base it on a modified monochrome Maximite or design a new one without any compromises and, as you can see, I chose the second route. Now that I have finished the Colour Maximite I might have a look at modifying the DM to give it colour. The big issue is with the firmware - it would not be a simple mod to MMBasic, it would require a reasonable amount of work and I have to say that I need a break before starting on something like that. Geoff Geoff Graham - http://geoffg.net |
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| donmck Guru Joined: 09/06/2011 Location: AustraliaPosts: 1313 |
Thank for the feed back Geoff. That was the sort of conclusion I was looking for. First take a break. Go to Europe for a month and recharge. Yes I know you are taking off soon. Have a good trip. 
Don... https://www.dontronics.com |
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| bigmik Guru Joined: 20/06/2011 Location: AustraliaPosts: 2914 |
Geoff, The extra colors can be put onto pins 11 and 12 of the VGA connector (currently not used) There are two work arounds that I can see to make the mod easier. 1. The VGA cable that plugs into the `mite can be modded to reflect the change or 2. A male to female adapter cable (or smple PCB) to convert the `modded' output back to `standard' output. This would be a Male-Female and plug into the VGA socket and then the VGA cable plugs into this. Regards, Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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