Considering the Propeller
PatM
Posts: 72
I have a project in mind that the propeller might be the answer to (or at least half the answer).
I have a need to display data on a small display - in color! Nothing fancy, simply line graphing two series. I've been looking for a solution that was affordable, hand-solderable, and (the other part of the problem) displayable on a small VGA style LCD of around 5-8". The minimum res required would be 240x128 at 4 colours, bigger and more colours is not necessary but would be nice.
I did a search on VGA in the Propeller manual PDF and learned very little besides how to set the register to activate the 8 pin VGA mode and something odd about 2 or 4 colour modes and tiles. Saw no mention of resolution capabilities etc.
So, a simple VGA question: Can I output a 4 colour VGA display at 240x128 (320x240 QVGA would be more than awesome) with four colours without having to resort to external memory and fancy workarounds? Something like DrawLine(x1,y1,x2,y2,colour) and WriteText(x,y,string)?
The app that I'm wanting to do fits well in an Atmel Mega32 but not quite into the Mega16.·The display currently used·is a 240x128 b/w graphic LCD (not serial, routines are on the Mega32). Does that sound like it would fit into a propeller (or two?).
I'll probably order up the protoboard for a lark anyway and, who knows, maybe I'll get the Hydra for fun too!
Oh, and Parallax, damned nice pricing on this new line! I learned on the BS2 but switched to Atmels due to both power and price. While lacking peripherals (adc, pwm, serial, etc), the multi-processor design would seem to more than make up for it. The ability to display composite or VGA directly (even if just low res and number of colours) is a HUGE deal.
P.S. Composite is just too messy, I really need that clean VGA look!
·
I have a need to display data on a small display - in color! Nothing fancy, simply line graphing two series. I've been looking for a solution that was affordable, hand-solderable, and (the other part of the problem) displayable on a small VGA style LCD of around 5-8". The minimum res required would be 240x128 at 4 colours, bigger and more colours is not necessary but would be nice.
I did a search on VGA in the Propeller manual PDF and learned very little besides how to set the register to activate the 8 pin VGA mode and something odd about 2 or 4 colour modes and tiles. Saw no mention of resolution capabilities etc.
So, a simple VGA question: Can I output a 4 colour VGA display at 240x128 (320x240 QVGA would be more than awesome) with four colours without having to resort to external memory and fancy workarounds? Something like DrawLine(x1,y1,x2,y2,colour) and WriteText(x,y,string)?
The app that I'm wanting to do fits well in an Atmel Mega32 but not quite into the Mega16.·The display currently used·is a 240x128 b/w graphic LCD (not serial, routines are on the Mega32). Does that sound like it would fit into a propeller (or two?).
I'll probably order up the protoboard for a lark anyway and, who knows, maybe I'll get the Hydra for fun too!
Oh, and Parallax, damned nice pricing on this new line! I learned on the BS2 but switched to Atmels due to both power and price. While lacking peripherals (adc, pwm, serial, etc), the multi-processor design would seem to more than make up for it. The ability to display composite or VGA directly (even if just low res and number of colours) is a HUGE deal.
P.S. Composite is just too messy, I really need that clean VGA look!
·
Comments
All you need is the Protoboard with the Accessory pack to get the VGA connector.· The largest all graphics display you can get (due to memory limitations) is 512 x 384.· The video hardware directly supports 4 colors per tile (a 16 x 16 or 32 x 16 area) chosen from as many as 128 different palettes, each with 4 possible colors.· There are also some complex schemes to increase the number of colors possibly, but, if you don't need that, I'd avoid it for now.
There are several different VGA drivers with the higher resolutions limited to text-only because of memory limitations.· The largest text display is 1600 x 1200 pixels and uses up most of the cogs and most of the available memory to produce it (mostly as a demonstration that it's possible).
At the beginning of the list of discussion threads for this (Propeller) forum, there's a "sticky thread" called "Good thread index".· If you look at that, there's a section labelled "Visual" containing various links to threads about video output including some VGA demos and discussions of how video works on the propeller.· There's also a link to the 1600 x 1200 pixel driver and demo program.
Post Edited (Mike Green) : 6/26/2007 12:47:09 AM GMT