Could the newly released Raspberry PI be something we could build upon? A quick way for an overpowered HP-41, perhaps?
Raspberry PI - something for us?
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03-04-2012, 07:06 PM
03-04-2012, 10:05 PM
It's cheaper than just about any other platform right now. I got one on the first order group last week, so hopefully it will pan out to be worthwhile! The last thing I did is an RPN calculator for my TV, but it might be fun! :-)
03-05-2012, 02:01 AM
Well - how about hooking it up to a small LCD screen, add a keyboard, battery...
03-05-2012, 03:04 AM
The Raspberry Pi is an interesting device and I'll probably use one for other things, but not for a calculator. It uses too much power to have decent battery life from disposable cells. Even with a rechargeable lithium polymer battery, the battery life will be quite limited. The DIY4X design that Richard and I have been working on uses electronics that should cost less than the Raspberry Pi, except for the display and keyboard (which obviously the Raspberry Pi does not include). The DIY4X display is by far the most expensive part. The DIY4X processor is an ARM Cortex-M3 running at up to 48 MHz, but typically 14 MHz. The latest version, which is just being installed on a board today, has 1MB of flash and 128KB of RAM. That's nowhere near as powerful as the Raspberry Pi, which has a 700 MHz ARM11JZFS and 256MB of RAM. However, the DIY4X uses about 30mW vs. the Raspberry Pi uses 3.5W for the currently shipping Model B, and 2.5W for the not-yet-available Model A. The main disadvantage of the DIY4X compare to Raspberry Pi is that there are exactly 3 DIY4X units in existence today, vs. thousands of Raspberry Pi units, with more on the way soon. However, if anyone is serious about wanting to do calculator development using a DIY4X or DIY5 platform, they should contact us, as we can make more. The cost will be more than $35, but it is (IMNSHO) a much more suitable calculator platform.
03-05-2012, 04:55 AM
I'm tempted :-)
03-05-2012, 05:51 AM
WP (or whatever) 43S? Maybe even 43G?
03-05-2012, 06:06 AM
So we've got to decide between the WP 13S based on the 15cc hardware and the 43S or 43G based on the DIY RPN hardware :-)
03-05-2012, 08:00 AM
Perhaps the x48 emulator could be ported to the Raspberry Pi as it is already available for the Linux operating system. Nick
03-05-2012, 08:36 AM
There's no doubt in my mind: use the DIY-based design!! Please?
03-05-2012, 09:03 AM
43S, 43S, 43S!!! :-)
03-05-2012, 10:16 AM
Quote: I presume that the smiley at the end of the sentence means that you are not actually considering development of a "WP 13S", correct? My impression has been that you did not consider the 15c LE (or 12c+) platform to be a viable development platform due to its display limitations. edit - per Marcus' message, WP 13S would be for the the DM-15cc, not the 15c LE or 12c+.
Edited: 7 Mar 2012, 1:22 p.m. after one or more responses were posted
03-05-2012, 10:24 AM
Jeff, the 15cc mentioned in the previous post is not the LE. Its main advantage: It has a dot matrix display which would allow the 34s menu/catalogue system to be ported over. Programming with key codes is out of question.
03-05-2012, 11:54 AM
It has already been done. I ported a number of emulators to ARM Linux a long time ago. Port is overstating it a bit, more like "make" with a few patches.
Links:
03-05-2012, 04:05 PM
I already intend to make some "early access" DIY4X or DIY5 units available to the WP-34s team. I brought it up in this thread in case any other calculator developers want to work on firmware on this platform. These "early access" units are NOT going to be a general-availability calculator. They are hand-made prototypes. It is our intent to offer an actual product in the not-too-distant future, but we still have a lot of work to do to make that happen.
03-05-2012, 04:27 PM
You can count on me. :-)
03-05-2012, 06:09 PM
Quote:
I don't think a BCM2835 is a serious design-in contender for any
IMHO the real challenge of producing a generic pocket calculator
I'd be delighted to find I've overlooked a viable source. But
One possibility here may be to pool overall interest and leverage
03-05-2012, 07:50 PM
What vendor makes the display you use in your calculator?
03-06-2012, 12:31 AM
Quote:
It is just a proof of concept grafting of a graphic module into
But to answer your question, the module shown in the graphic
I believe for an LCD display COG is about the only economical
03-06-2012, 05:46 AM
That looks like a good beginning for calculators to run on this device. Nick
03-06-2012, 06:14 AM
One can write calculator software for the Kindle and leverage unbeatable HW at <$100: 256 MB RAM, 1-3 GB flash, 6" 800x600 Eink display. Versions with and without keyboard exist, latter with or without touch screen. The display may be a little large for a RPN-style machine but is great for an RPL-style machine (or any grapher). If the Kindle touch would be used and half the screen went away for keys, the 6" screen becomes a 3" screen, which isn't too large for RPN-style either. I'm not sure about the legality of it, but repurposing a Kindle would be another possible option: the device can be jailbroken/unlocked and used as an ARM Linux machine with a good stack of technologies included. The outer housing and fiddly keyboard could be replaced with something else (or, maybe the keyboard area only could be reworked). All of this goes also for the nook, I suppose.
03-06-2012, 08:28 AM
COG = Chip On Glass COB = Chip On Board (just a little help for those who are not faliliar with these acronymns, and don't want to spend five minutes looking for an explanation elsewhere)
03-06-2012, 11:05 AM
Quote:
It is quite tempting to leverage a commercial product which has
So in part developing a new platform is about half getting
That aside, a silver lining of sorts is the technology
03-07-2012, 07:26 PM
This is a problem to the point of being ridiculous. Every design I've worked on thus far has ended up requiring a custom display. I toyed with building designs around available glass, but everything I've found has been a mediocre compromise at best. It would be great to see this community pool its resources and talent in order to produce some great hardware... But I'm not holding my breath. Considering the success demonstrated by WP-34S, I have no question that great hardware will spur fantastic software development. Regarding Raspberry Pi: as stated before in this thread it's far too power hungry. A similar product better suited to calculators could be produced at a similar price point with little difficulty. My current plans for OpenRPN call for a SoM most likely built on a SODIMM board. Not only does this mean a singe module type could be used for multiple calculator form factors, but the module should be able to sell as a stand alone product too.
03-08-2012, 01:36 AM
Quote:
Regrettably the fundamental limitation of the LPC1114 is
I'd considered pushing non-executable data to a secondary SPI
Quote:
Yea. Aside from some sort of historical reverence for a
03-08-2012, 01:40 AM
Custom LCDs aren't all that expensive to have made, both in terms of NRE and per-unit production cost, if you can use a segmented display. A dot matrix display (glass only, without a controller embedded in the display) is also not too expensive, but not practical for a matrix much larger than 96x32 due to the large number of interconnects needed.
03-08-2012, 02:06 AM
I'm sure, WP 34S will not fit into 32KB of ROM. 8KB of RAM is better than what we have now but the base routines alone easily make up 3/4 of the firmware image. The rest is keystroke programs which might be fetched from an external device without performance issues.
03-08-2012, 02:43 AM
The 15cc is supposed to have pads for a large serial flash device. It should be possible to do the 34S core in 32kb and have lots of keystroke programs for the remaining functionality in the serial flash. We'd have to move the keyboard decoder and the display code into the serial flash which would be a large undertaking -- these two are a large portion of the firmware. Then the remaining higher maths functions and we might fit.
03-08-2012, 12:20 PM
Quote:
The concurrent read rate out of SPI flash relative to the
Yet another concern I had was of holding the SPI device in a
Quote:
I'd been expecting NXP to drop a more suitable SoC into the
03-09-2012, 12:58 PM
Quote:
Contemporary controllers aren't available for even modest
Older controllers can be found in SMD packages but their power
03-09-2012, 04:15 PM
Die bonding is not viable for very-low-volume hand-made products, but even in modest production volumes (250 and up), it is not too expensive. |
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