A multi processor PIC computer :-)
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From: Jan Panteltje on 9 Jun 2010 10:18 A multi processor PIC computer :-) ftp://panteltje.com/pub/multi_processor_PIC_LED_color_controller_hardware_img_2002.jpg I modified my LED color controller a bit so it has 3 independent hardware PWM channels. One PIC is the master, is controlled via ethernet, and its PWM unit drives blue. It forwards the other color levels via very fast RS232 to 2 other PICs, one does the red pwm, and the other one does the green PM thing. There are 4 clocks in this system, 25 MHz for the ethernet controller, and 3 x 64 MHz internal clocks for the PICs. I was watching the LED strips for interference, you can see it on the scope, but not in the light output.... PWM is about 15 kHz, 8 bits resolution, probably with harmonics up to...... Anyways, multi-processor PIC is here :-)
From: Grant on 9 Jun 2010 10:29 On Wed, 09 Jun 2010 14:18:42 GMT, Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote: >A multi processor PIC computer :-) > ftp://panteltje.com/pub/multi_processor_PIC_LED_color_controller_hardware_img_2002.jpg > >I modified my LED color controller a bit so it has 3 independent hardware PWM channels. >One PIC is the master, is controlled via ethernet, and its PWM unit drives blue. >It forwards the other color levels via very fast RS232 to 2 other PICs, >one does the red pwm, and the other one does the green PM thing. > >There are 4 clocks in this system, 25 MHz for the ethernet controller, >and 3 x 64 MHz internal clocks for the PICs. > >I was watching the LED strips for interference, you can see it on the scope, >but not in the light output.... >PWM is about 15 kHz, 8 bits resolution, probably with harmonics up to...... Don't need use so high a frequency for LEDs? >Anyways, multi-processor PIC is here :-) > I repaired a cricket ball tosser recently, the controller box had two PIC chips in it, there was no manual so I have no idea how they split the work between them. Perhaps it's easier than running multitasking OS in the PICs? Grant. -- http://bugs.id.au/
From: Jan Panteltje on 9 Jun 2010 13:58 On a sunny day (Thu, 10 Jun 2010 00:29:54 +1000) it happened Grant <omg(a)grrr.id.au> wrote in <109v06tne7fgocc4d117ttgsusap3ofagm(a)4ax.com>: >On Wed, 09 Jun 2010 14:18:42 GMT, Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote: > >>A multi processor PIC computer :-) >> ftp://panteltje.com/pub/multi_processor_PIC_LED_color_controller_hardware_img_2002.jpg >> >>I modified my LED color controller a bit so it has 3 independent hardware PWM channels. >>One PIC is the master, is controlled via ethernet, and its PWM unit drives blue. >>It forwards the other color levels via very fast RS232 to 2 other PICs, >>one does the red pwm, and the other one does the green PM thing. >> >>There are 4 clocks in this system, 25 MHz for the ethernet controller, >>and 3 x 64 MHz internal clocks for the PICs. >> >>I was watching the LED strips for interference, you can see it on the scope, >>but not in the light output.... >>PWM is about 15 kHz, 8 bits resolution, probably with harmonics up to...... > >Don't need use so high a frequency for LEDs? True, but it runs 64 MHz clock, I think I selected the biggest divider :-) (Not sure, actually). > >>Anyways, multi-processor PIC is here :-) >> >I repaired a cricket ball tosser recently, the controller box had two PIC >chips in it, there was no manual so I have no idea how they split the work >between them. Perhaps it's easier than running multitasking OS in the PICs? > >Grant. You need a bit of a stack space for that. In this case I need 3 hardware PWM generators. The Microchip site lists a few PICs that have 3, but those are not DIL. I like the DIL packages, as it allows me to make proto types without having to make boards or have boards made. Easier to change things. And at less then 2 $ who cares 1 PIC for 5$, or 3 of 2 $, in small quantities. If somebody needs a million controllers then I will look again :-) The idea of assigning processors to different tasks, as processors are so cheap, makes a lot of sense to me. In our nervous system many things are autonomous too, think reflexes. I use a very simple system, the master sends serial data on the TX output, all the slaves listen on that wire, direct connection. Commands have the form of GnnnLF for nnn is 0-255 to set green, RnnnLF to set red. You can at least address 26 x 2 (upper and lower case) controllers that way. Software is largely the same too, just change a few characters.
From: Jan Panteltje on 9 Jun 2010 14:11 On a sunny day (Wed, 09 Jun 2010 12:30:46 -0500) it happened Vladimir Vassilevsky <nospam(a)nowhere.com> wrote in <_s-dnV1ZfboAUpLRnZ2dnUVZ_uidnZ2d(a)giganews.com>: >Every other programmable core on the PCB is a headache for the >development, manufacturing and support. There will be additional >programming operations. There will be inevitable version conflicts. Well, I have more then 1000 soft version out in the public domain ONLY. I think I have a good system, never a problem. >There will be a lot of overhead on defining and maintaining the >communication protocol between the cores. Strange I never noticed that :-) You are a bit weak on networking right?
From: Grant on 9 Jun 2010 17:39
On Wed, 09 Jun 2010 17:58:17 GMT, Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote: >On a sunny day (Thu, 10 Jun 2010 00:29:54 +1000) it happened Grant ><omg(a)grrr.id.au> wrote in <109v06tne7fgocc4d117ttgsusap3ofagm(a)4ax.com>: > >>On Wed, 09 Jun 2010 14:18:42 GMT, Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote: >> >>>A multi processor PIC computer :-) >>> ftp://panteltje.com/pub/multi_processor_PIC_LED_color_controller_hardware_img_2002.jpg >>> >>>I modified my LED color controller a bit so it has 3 independent hardware PWM channels. >>>One PIC is the master, is controlled via ethernet, and its PWM unit drives blue. >>>It forwards the other color levels via very fast RS232 to 2 other PICs, >>>one does the red pwm, and the other one does the green PM thing. >>> >>>There are 4 clocks in this system, 25 MHz for the ethernet controller, >>>and 3 x 64 MHz internal clocks for the PICs. >>> >>>I was watching the LED strips for interference, you can see it on the scope, >>>but not in the light output.... >>>PWM is about 15 kHz, 8 bits resolution, probably with harmonics up to...... >> >>Don't need use so high a frequency for LEDs? > >True, but it runs 64 MHz clock, I think I selected the biggest divider :-) >(Not sure, actually). > >> >>>Anyways, multi-processor PIC is here :-) >>> >>I repaired a cricket ball tosser recently, the controller box had two PIC >>chips in it, there was no manual so I have no idea how they split the work >>between them. Perhaps it's easier than running multitasking OS in the PICs? >> >>Grant. > >You need a bit of a stack space for that. >In this case I need 3 hardware PWM generators. >The Microchip site lists a few PICs that have 3, but those are not DIL. >I like the DIL packages, as it allows me to make proto types without having to make boards or have boards made. >Easier to change things. >And at less then 2 $ who cares 1 PIC for 5$, or 3 of 2 $, in small quantities. >If somebody needs a million controllers then I will look again :-) > >The idea of assigning processors to different tasks, as processors are so cheap, makes a lot of sense to me. >In our nervous system many things are autonomous too, think reflexes. >I use a very simple system, the master sends serial data on the TX output, >all the slaves listen on that wire, direct connection. >Commands have the form of >GnnnLF for nnn is 0-255 to set green, >RnnnLF to set red. > >You can at least address 26 x 2 (upper and lower case) controllers that way. >Software is largely the same too, just change a few characters. I've just started using PICs, programmed enough (RTC, HD44780 LCD module controller, multitasking timebase) to know they're okay for what I want. I return to microcontrollers for first time since '93 when PICs were becoming popular but I was using 'HC05 series controllers (C8, J2, K1). So I've seen the RISC and can get the assembler to put multi-module code where I expect it now. Yet to do user input, I'm more interested in standalone operation than serial interface, so not done rs232 or inter-chip comms yet. So many things I'd like to try :) Even bought a 192x128 LCD graphics display to try driving one day -- the sort without a char gen, so I'd have to work in a char pattern memory for text on that too. Done that back in '80s with little 8085 box, in assembler. Grant. -- http://bugs.id.au/ |