 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Microcontroller and PC projects : PIC32 28/40 pin device
| Author | Message | ||||
elproducts Senior Member  Joined: 19/06/2011 Location: United StatesPosts: 282 |
Microchip officially announced a low pin count PIC32 which will be available in DIP package. The data sheet for these new parts shows an upgrade path to 128k flash in the future. Is 128K too small for the Maximite code? A 28/40 pin DIP version would make an easy to assemble Maximite kit for students who can't solder a 100 pin TQFP. http://finance.yahoo.com/news/Microchip-Introduces-Smallest- bw-2196451699.html?x=0&.v=1 www.elproducts.com |
||||
Geoffg Guru  Joined: 06/06/2011 Location: AustraliaPosts: 3194 |
Wow, this is great. As far as I can see the largest version has 32KB flash and 8K RAM which will not support MMBasic. MMBasic would fit into 128K flash but the amount of RAM could be the limiting issue. Programming the PIC32 is a wonderful experience as it uses 32 bit integers and there are no strange architectural issues that you need to work around. It is just like writing programs for a mini computer. The PDIP package makes it easy to use the chip as an everyday controller. The only issue is that the MIPS instruction set does use up memory so it could be easy to run short. Geoff Geoff Graham - http://geoffg.net |
||||
| elproducts Senior Member Joined: 19/06/2011 Location: United StatesPosts: 282 |
The 128k parts shown in the data sheet have 32k RAM. The chip also runs slower at 40Mhz instead of 80Mhz. And only the 28 pin is PDIP. Maybe this can be the Maximite-Tiny in the future. 
www.elproducts.com |
||||
| mookster1 Regular Member  Joined: 10/06/2011 Location: New ZealandPosts: 81 |
A PIC32 in a DIP package? That is pretty awesome  Maybe it'll be possible to whack up a Maximite on a piece of Veroboard in future...  Capacitance is futile - roll on 2012! |
||||
sparkey Senior Member Joined: 15/06/2011 Location: AustraliaPosts: 819 |
i think this will be of great advantage too all especially students who cant solder smd and if i had one in my hands it would prolly be running my inverter ...does anybody have a stockist other than microchip them selves ...///.../// technicians do it with least resistance |
||||
VK6MRG Guru Joined: 08/06/2011 Location: AustraliaPosts: 347 |
If MMbasic was stripped down IE no VGA, keyboard, sound, etc. would that fit onto the DIP PIC32? The Maximite Micro! Its easier to ask forgiveness than to seek permission! ............VK6MRG.............VK3MGR............ |
||||
| Geoffg Guru Joined: 06/06/2011 Location: AustraliaPosts: 3194 |
Maybe, but 32K of RAM is very tight. Geoff Geoff Graham - http://geoffg.net |
||||
vasi Guru Joined: 23/03/2007 Location: RomaniaPosts: 1697 |
Then maybe DK-Basic... Hobbit name: Togo Toadfoot of Frogmorton Elvish name: Mablung Miriel Beyound Arduino Lang |
||||
| VK6MRG Guru Joined: 08/06/2011 Location: AustraliaPosts: 347 |
I still think it can be and should be done. All I need for one of my projects is 10 I/O's and if needed I can get away with 8. My code is only a few k, and no logging is required. So if a stripped down version of MMbasic with the on board A: flash drive to store the code was able to be shoe horned into this new PIC32 it would be another Maximite option. Maybe the internal flash drive is undoable! 
Anyone agree? Its easier to ask forgiveness than to seek permission! ............VK6MRG.............VK3MGR............ |
||||
| VK6MRG Guru Joined: 08/06/2011 Location: AustraliaPosts: 347 |
Can someone tell me what the minimum size MMbasic could go down to? Its easier to ask forgiveness than to seek permission! ............VK6MRG.............VK3MGR............ |
||||
donmck Guru Joined: 09/06/2011 Location: AustraliaPosts: 1313 |
I sense from what Geoff has said, that it would be a very tight squeeze with possibly a much crippled version. Doesn't mean it can't be done, but if the chip price is right, I see Picaxe type devices growing from it. Sure it is a very big advantage having a standard DIP device for small users, hobbyists etc. Cheers Don... https://www.dontronics.com |
||||
| mookster1 Regular Member Joined: 10/06/2011 Location: New ZealandPosts: 81 |
Well as one of those aforemented students who can't solder, having a Maximite with a PIC32 in a DIP package, I would have just bought the board and the PIC32 and saved myself a bit of dosh by sourcing the components myself, instead of buying an overpriced kit! As for 32K of RAM in the PIC32 DIP, is it possible to use bitbanging to extend that a bit (as there is no native addressing for external RAM?) i.e. have a bank of SRAM that not only talks to the Maximite but can also be accessed directly by other devices via a serial bus? May be a bit slower but would solve the RAM issue. If MMBasic can't be squeezed down to fit the PIC32 DIP, then would writing software in assembler be an option? The reason I say this is that you won't have the overhead of an interpreter. While it kind of takes away the ability for beginners to learn programming as easily, assembler is still quite powerful. However having routines stored on an SD card (e.g. draw characters in a standard font at (x,y)) would be a necessity because having to remember big routines such as that every time you write a program is awfully inefficient. What do you guys think? Capacitance is futile - roll on 2012! |
||||
| pito Newbie  Joined: 09/06/2011 Location: Posts: 25 |
..these smaller gadgets would be ideal for a 32bit forth implementation.. ..like the 16bit flashforth for pic24 or dspic33, for example.. http://flashforth.sourceforge.net/ p. |
||||
| Geoffg Guru Joined: 06/06/2011 Location: AustraliaPosts: 3194 |
I have not tried it but you could probably get it to run with 128KB flash and 64KB of RAM. Shrinking software like this is not easy as there were many decisions made in the early days of the design that assumed that 128K RAM was available. Probably the best approach would be to develop a new interpreter with a new structure but reuse parts of MMBasic that fitted the smaller memory space requirement. The people who are in the best position to exploit this are the developers of the PICAXE as their interpreter is already optimised for small memory. PICAXE BASIC running on this chip would be awesome. On another post. Rather than use assembler you should consider C. The MIPS CPU in the PIC32 assumes that the code is being generated by an optimising compiler and therefore it is not easy writing in assembler. C is much easier and if you are going to learn anything C is the better choice. Geoff Geoff Graham - http://geoffg.net |
||||
| elproducts Senior Member Joined: 19/06/2011 Location: United StatesPosts: 282 |
Geoff, I tried to build the V2.7 project to see how much space it took up but kept getting errors finding files. I'm sure its something I'm doing wrong as when I loaded the project MPLAB couldn't find the many of the files. I had to locate them individually. I'll figure it out. Your post brings up a good question though. Did you use the pro version of the C32 with full optimization or the free version? Did you optimize at all? Doubt if this will shrink RAM much but I was just curious. I've been looking over the code and you are amazing. That is a lot of code work done for an open source project. I am even more impressed with Maximite and your skills. If people really look at how much code is there they would think twice about asking for more features. Altronics should charge $300 and give all the extra to Geoff. www.elproducts.com |
||||
| Geoffg Guru Joined: 06/06/2011 Location: AustraliaPosts: 3194 |
Thanks for the compliments. I develop using the Lite version with optimisation level 1 and when I am ready to produce the final version I load the time limited evaluation compiler which gives me level 2 optimisation. Moving from level 1 to 2 makes the code about 10% faster but going to S makes it a bit slower than level 2. I cannot go to level 3 as the compiler is so enthusiastic that it removes some of my code. I don't know about the space reduction but it is probably similar to the speed improvement, RAM usage will not change at all. Geoff Geoff Graham - http://geoffg.net |
||||
 Print this page |
