Reprap Electronics Devolpment

Larry_Pfeffer Wrote:
-------------------------------------------------------

> I just found out about a low-cost board with an
> LPC1768 chip, with the I/O lines broken out to
> header pins.
> [shop.ngxtechnologies.com]
> roducts_id=65
>
> The price is right, a bit under $33 US. I ordered
> a couple, along with a USB/JTAG interface (that
> supports open OCD.)

Of course, shortly after ordering these new techno-toys, I see they'll soon be obsolete. Arm has announced a new Cortex M processor, the M4 **:

[www.arm.com]

And NXP is among the licensees: [www.nxp.com]


** I hope they know to skip using the moniker M5, for the version after M4 -- any Star Trek fan knows that M5 is a *bad* name for a computer!

---

Larry Pfeffer,

My blog about building repstrap Cerberus:
[repstrap-cerberus.blogspot.com]

casainho

Those look like very nice boards to start working with. However, every time I try looking for products with the numbers you gave, all I find are processor ships (at surprisingly low prices! But I would like to work with one of the breakout boards, especially the one that communicates with both USB and ethernet. But who builds them? And what part numbers do I look for?

Mike

rocket_scientist Wrote:
-------------------------------------------------------
> casainho
>
> Those look like very nice boards to start working
> with. However, every time I try looking for
> products with the numbers you gave, all I find are
> processor ships (at surprisingly low prices! But I
> would like to work with one of the breakout
> boards, especially the one that communicates with
> both USB and ethernet. But who builds them? And
> what part numbers do I look for?

Unfortunately, I think Opendous will not assembly and sell that boards. However he provides all the source files for KiCad! Even he provides FreeRTOS working demo with Ethernet and USB working!

Or we go with the source files and buy the boards on some shop and after we assembly them... I wish Opendous could sell them...

Another option is to go with XDuino, and Arduino with a ARM Cortex: [www.xduino.com]

There are many boards on Market... and USB and Ethernet make them expensive! Are you sure USB and Ethernet are need?

23€ -> ARM Cortex with 128K Bytes Program Flash (BETTER than Arduino Mega but at half of the price!);


13€ -> ARM Cortex 32 kB Flash and USB (Good for extruder board and is very cheap!).


Look here also for other cheap ARM boards: [www.olimex.com]
And the price list: [www.olimex.com]

Edited 2 time(s). Last edit at 03/19/2010 12:31PM by casainho.

---

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]

Ethernet is least needed, until the machines work so well that you can run them from a computer in another room. But USB is becoming much more common, and serial ports are disappearing from laptops, so switching from RS232 (which requires a level shifter like the MAX232) to USB which uses the same logic levels as 5 volt electronics, and even provides some power for small devices should make it much easier to program and control from a wide range of new computers.

Maybe I will have to practice my laser-printer, dual side boards and surface mount devices techniques and make one.

Mike

Larry_Pfeffer Wrote:
-------------------------------------------------------
> Larry_Pfeffer Wrote:
> --------------------------------------------------
> -----
>
> > I just found out about a low-cost board with an
> > LPC1768 chip, with the I/O lines broken out to
> > header pins.
> >
> [shop.ngxtechnologies.com]
>
> > roducts_id=65
> >
> > The price is right, a bit under $33 US. I
> ordered
> > a couple, along with a USB/JTAG interface (that
> > supports open OCD.)
>
> Of course, shortly after ordering these new
> techno-toys, I see they'll soon be obsolete. Arm
> has announced a new Cortex M processor, the M4 **:
>
>
> [www.arm.com]
> rtex-m4-processor.php
>
> And NXP is among the licensees:
> [www.nxp.com]
>
>
> ** I hope they know to skip using the moniker M5,
> for the version after M4 -- any Star Trek fan
> knows that M5 is a *bad* name for a computer!


The M4 is designed for different tasks, the M3 has only been out a couple of years, they also just brought out the lesser M0 for simpler tasks.

The main difference between the M3 and M4 is a FPU.

Most embedded control systems don't need an FPU, Inputs are fixed point, Outputs are fixed point, just lazy on the part of the coder if they switch to Floating point inside the micro.

In general, any ARM Cortex microcontroller is pretty compelling with many vendors and many product to choose from. In my opinion, the LPC17xx family is the best of the lot however.

[ics.nxp.com]

The MBED approach is great for people that are new to developing code for microcontrollers or those that don't want to get bogged down installing development tools, etc. MBED simply takes the pain out of it.

[mbed.org]

You might find the Hitex LPC sticks to be of interest.

[www.hitex.com]
[www.hitex.com]

Another one is the LPCxpresso boards from Embedded Artists. The LPC13xx family is a little brother to the LPC17xx.

[www.embeddedartists.com]
[www.embeddedartists.com]

[ics.nxp.com]

And if you need really low cost there is the baby brother, the LPC11xx family.

[ics.nxp.com]

The LCPxpresso is the next logical step from a software development point of view. LPCxpresso uses Eclipse IDE and GNU tools for development (all open source).

[ics.nxp.com]

Even if you weren't going to use LPCxpresso boards it is likely that you would the Eclipse IDE and GNU tools for ARM software development.

There are many good development boards out there and I don't intend to promote any particular one. The MBED, Olimex, Hitex LPC sticks, and Embedded Artists LPCxpresso boards are the least expensive of the ones I have looked at. There are more full featured development boards from many vendors including Embedded Artists, CodeRed Technologies, Kiel, IAR Systems, Future Designs, etc.

The point is... the ecosystem for LPC17xx is robust even though it is a relatively new device. It is a great microcontroller and I am personally very tempted to develop Mendel electronics based on the LPC17xx.

Note that without hesitation I would highly recommend looking into FreeRTOS if you are considering developing with a microcontroller of any type. There are example ports to a wide array of microcontrollers and boards. I've been using it for several years now and it just keeps getting better and better.

[www.freertos.org]
[www.freertos.org]

TC

P.S. I don't have any affiliation with any product or company mentioned here. I just happen to be working with these devices and wanted to share information with people that might be interested.

You forgot to include that the LPCxpresso comes complete with a JTAG.

For £20 I bought one!

Indeed. Some of the development boards have started to integrate USB to JTAG intefaces. From what I have seen these are all based on the FTDI FT2232 chip.

[www.ftdichip.com]

This approach eliminates the need for an external JTAG probe for debugging.

If you are doing "bare metal ARM development" (installing your own tools - Eclipse, GNU tools, etc.) then you will also be interested in OpenOCD for connecting the GNU debugger to the JTAG interface (FTDI chip).

[openocd.berlios.de]

TC

TC Wrote:
-------------------------------------------------------
> Indeed. Some of the development boards have
> started to integrate USB to JTAG intefaces. From
> what I have seen these are all based on the FTDI
> FT2232 chip.
>
> [www.ftdichip.com]
>
> This approach eliminates the need for an external
> JTAG probe for debugging.
>
> If you are doing "bare metal ARM development"
> (installing your own tools - Eclipse, GNU tools,
> etc.) then you will also be interested in OpenOCD
> for connecting the GNU debugger to the JTAG
> interface (FTDI chip).
>
> [openocd.berlios.de]
>
> TC

The LPCxpresso one is based on an LPC3154 ARM9, the device has a USB interface and DFU capability, basically the system has no flash, firmware is loaded onto the device at boot into RAM by the device driver.

It supports the conventional ARM JTAG interface and the new SWD interface.

But is not OpenOCD based, however due to the above interface if someone was to write firmware for it then you could in theory implement this.

Note to casainho, the LPC1114 only supports the SWD interface which is not OpenOCD compatible at the time of writing.

I love the LPC17xx series the ethernet interface capabilty on the larger devices could be useful. And for their capability they are very cheap!

The LPC1114 is perfectly capable of running the whole system, the only additional part required is something to generate PWM for the heater as this series does not support PWM directly. It runs at three times the Mhz of the Arduino and the core is 32bit so fewer operations are typically required.

Would suggest either the LPC1343, which has integrated USB and can be programmed easily via this interface (appears as a USB flash drive, this is programmed from the factory). But this still requires a PWM generator.

Or an LPC1764 this is the cheapest of the larger devices with Ethernet.

This can generate PWM directly and provide the ethernet interfaces and a multitude of other interfaces if they are required, including USB.

It doesn't have the USB bootloader, its serial, but you don't need an ICSP programmer as with the AVR parts.

Secondly they are cheaper than the ATMega128 in single unit quantities, everyone on here is so keen to promote.

annodomini2 Wrote:
> The LPCxpresso one is based on an LPC3154 ARM9,
> the device has a USB interface and DFU capability,
> basically the system has no flash, firmware is
> loaded onto the device at boot into RAM by the
> device driver.
>
> It supports the conventional ARM JTAG interface
> and the new SWD interface.
>
> But is not OpenOCD based, however due to the above
> interface if someone was to write firmware for it
> then you could in theory implement this.

That LPCxpresso seems to be expensive and with some problems with Free Software tools.


> Note to casainho, the LPC1114 only supports the
> SWD interface which is not OpenOCD compatible at
> the time of writing.

Yes :-( -- but OpenOCD have already some dev code for SWD, no? I think soon it may work with SWD, what do you think?


> I love the LPC17xx series the ethernet interface
> capabilty on the larger devices could be useful.
> And for their capability they are very cheap!

Yes, LPC17xx have big flash size, which is important I guess.


> The LPC1114 is perfectly capable of running the
> whole system, the only additional part required is
> something to generate PWM for the heater as this
> series does not support PWM directly. It runs at
> three times the Mhz of the Arduino and the core is
> 32bit so fewer operations are typically required.
>
> Would suggest either the LPC1343, which has
> integrated USB and can be programmed easily via
> this interface (appears as a USB flash drive, this
> is programmed from the factory). But this still
> requires a PWM generator.

Olimex have cheap LPC1114 and LPC1343 boards but if ATmega328 have small memory, then that both LPCs may also have small memory. LPC17xx is the best option I think. Maybe LPC1xxx just for extruder??


> Or an LPC1764 this is the cheapest of the larger
> devices with Ethernet.

Something I do not understand. Is Ethernet important for RepRap?


> This can generate PWM directly and provide the
> ethernet interfaces and a multitude of other
> interfaces if they are required, including USB.
>
> It doesn't have the USB bootloader, its serial,
> but you don't need an ICSP programmer as with the
> AVR parts.

While I think JTAG cable is really cheap and are many options on market which is good, it is a must for a developer to be able to do debug. BUT users should not need to buy JTAG and configure software to flash firmware, so a USB bootloader is a must, IMO.


> Secondly they are cheaper than the ATMega128 in
> single unit quantities, everyone on here is so
> keen to promote.

AVR don't have Free/Open tools for debug :-(

---

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]

Quote
casainho

AVR don't have Free/Open tools for debug :-(

??? ??? ??? ???

While AVR Studio is not open, It is most defiantly free. Sometimes they want some registration info. Usually I get the latest build from atmel.no/beta_ware/.

Studio uses the WINAVR gcc suite, which is free and open, although this does require a Window$ machine.

I patched the older JTAG ICE code to run on the butterfly processor. [1]

Most of the AVR JTAG protocol is open and well documented. I think there are about 4 debug/trace operators which are proprietary and undocumented. All the protocols for reading/writing any part of the chip are documented. Also documented is the serial protocol to communicate with the JTAG clone. I think there is a version of GDB which can use the documented side of the JTAG to do JTAG debugging. [I use the free AVR Studio myself]

I seem to recall that the mega128 is one of the processors which does work with the older atmel JTAG clones. Why the m128 is so popular.

So I am quite interested why you do not feel there is no Free/Open tools for debug. Do you mean no Linux tools? Or are you wanting free hardware too?


-julie

sheep Wrote:
-------------------------------------------------------
> So I am quite interested why you do not feel there
> is no Free/Open tools for debug. Do you mean no
> Linux tools? Or are you wanting free hardware
> too?

Come on, you know that anyone is doing debug on Arduino because of lack of cheap and Free/Open hardware debug tools!

Another ARM Arduino: [leaflabs.com]



Edited 2 time(s). Last edit at 03/29/2010 02:20PM by casainho.

---

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]

I think he is talking a full IDE debug enviorment, with the ability to set break points, interrupt a running program and examine variables in context etc.

With the primative IDE for the Ardunio you end up with verbose output statements to prove chunks of code are running, etc.

casainho Wrote:
-------------------------------------------------------
> annodomini2 Wrote:
>
> That LPCxpresso seems to be expensive and with
> some problems with Free Software tools.
>

£20 for a dev board with Full JTAG and dev tools is ridiculously cheap

>
> Yes :-( -- but OpenOCD have already some dev code
> for SWD, no? I think soon it may work with SWD,
> what do you think?
>
>

Its in development, but not finished

> > I love the LPC17xx series the ethernet
> interface
> > capabilty on the larger devices could be
> useful.
> > And for their capability they are very cheap!
>
> Yes, LPC17xx have big flash size, which is
> important I guess.
>

Big flash isn't important, enough flash space is.

>
> > The LPC1114 is perfectly capable of running the
> > whole system, the only additional part required
> is
> > something to generate PWM for the heater as
> this
> > series does not support PWM directly. It runs
> at
> > three times the Mhz of the Arduino and the core
> is
> > 32bit so fewer operations are typically
> required.
> >
> > Would suggest either the LPC1343, which has
> > integrated USB and can be programmed easily via
> > this interface (appears as a USB flash drive,
> this
> > is programmed from the factory). But this still
> > requires a PWM generator.
>
> Olimex have cheap LPC1114 and LPC1343 boards but
> if ATmega328 have small memory, then that both
> LPCs may also have small memory. LPC17xx is the
> best option I think. Maybe LPC1xxx just for
> extruder??
>

See above, the problem would be the added cost for the PWM driver interface, not flash space.

You wouldn't need an extruder board the chip is quite capable of running the whole system.

The benefit for the extruder board comes with interchangable heads, using at hot swap capable bus interface.

>
> > Or an LPC1764 this is the cheapest of the
> larger
> > devices with Ethernet.
>
> Something I do not understand. Is Ethernet
> important for RepRap?
>

Ethernet has a number of benefits, mainly when running multiple machines.

And when you want to access the machine from multiple computers.

>
> > This can generate PWM directly and provide the
> > ethernet interfaces and a multitude of other
> > interfaces if they are required, including USB.
> >
> > It doesn't have the USB bootloader, its serial,
> > but you don't need an ICSP programmer as with
> the
> > AVR parts.
>
> While I think JTAG cable is really cheap and are
> many options on market which is good, it is a must
> for a developer to be able to do debug. BUT users
> should not need to buy JTAG and configure software
> to flash firmware, so a USB bootloader is a must,
> IMO.

Currently the AVR chips require a bootloader to be programmed with an ICSP programmer, this is not required with the NXP parts listed.

The USB->SerialTTL, is not a JTAG, its just a Serial interface, a second level bootloader can be programmed on the LPC17xx series to provide a programming interface on one of the other connections.

>
>
> > Secondly they are cheaper than the ATMega128 in
> > single unit quantities, everyone on here is so
> > keen to promote.
>
> AVR don't have Free/Open tools for debug :-(

You completely misunderstood my statement.

(to delete)

Edited 1 time(s). Last edit at 03/29/2010 05:52PM by casainho.

---

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]

annodomini2 Wrote:
-------------------------------------------------------
> casainho Wrote:
> --------------------------------------------------
> -----
> > annodomini2 Wrote:
> >
> > That LPCxpresso seems to be expensive and with
> > some problems with Free Software tools.
> >
>
> £20 for a dev board with Full JTAG and dev tools
> is ridiculously cheap

Yeah, but if you need say 4 boards, there is no reason to buy 4 times the JTAG. I already have my JTAG since a few years, no need to pay more for other(s).

Olimex solution equal to LPCxpresso (the same LPC1343) costs £11.7, so it's less £8 (probably because it do not have JTAG).


> > Yes :-( -- but OpenOCD have already some dev
> code
> > for SWD, no? I think soon it may work with SWD,
> > what do you think?
> >
> >
>
> Its in development, but not finished

On that case I would go with LPC17xx because have JTAG, Ethernet, USB, more flash and more IO pins.


> You completely misunderstood my statement.

Yeah, sorry. We know the same thinks I see.

Edited 1 time(s). Last edit at 03/29/2010 05:53PM by casainho.

---

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]

Quote
freds Wrote:

-------------------------------------------------------
> I think he is talking a full IDE debug enviorment,
> with the ability to set break points, interrupt a
> running program and examine variables in context
> etc.
>
> With the primative IDE for the Ardunio you end up
> with verbose output statements to prove chunks of
> code are running, etc.

The processor is still and AVR, and as noted the JTAG hardware is 50USD or about 20UKP. This is a one time expense. The plans for the JTAG got leaked out some 10 years of so back for the older AVR chips like the mega128. There are dozens of capable JTAG clones out there that can be had for a few groats, florens, ducats or what ever form of sheepskins used for barter.

I have spent the day working with such a device. No this is not Arduino, but it is the same hardware. The code has to be ported to gcc, but most of the Arduino package is a gcc wrapper. So if one can dirty the hands and use a windows IDE, Then one can have all the breakpoints and watches desired. There is also some support in GDB for the protocol used by the JTAG clones based on the leaked schematics.

Probably what we have here are some language differences. On the other hand I do not want to see lurkers of these forums to be misinformed.

The AVR family is in my opinion the best choice at the moment for the maximum return on time and effort spent. There is always something better around the corner. To get there, it takes time to look at what one has now, otherwise it is just a dream and illusion.

-julie

sheep Wrote:
-------------------------------------------------------
> The AVR family is in my opinion the best choice at
> the moment for the maximum return on time and
> effort spent. There is always something better
> around the corner. To get there, it takes time
> to look at what one has now, otherwise it is just
> a dream and illusion.

You have Olimex selling ARM Cortex M3 boards with USB for $13. This ARM Cortex is much more powerfull than AVR and much more cheap. (And this cheap ARMs comes from even Atmel, Philips NXP, Texas Instruments, and so on...)

13€ -> ARM Cortex 32 kB Flash and USB (Good for extruder board and is very cheap!) (same board for the LPC1343).


And the solutions for debug Arduino boards (ATmega8/168/328) come from ONLY a source: Atmel, and ARE CLOSED, not as you are saying.

I had being working professionaly with AVR and doing workshops of Arduino. But it is clear that ARM has advantage now.

Edited 3 time(s). Last edit at 03/30/2010 06:46AM by casainho.

---

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]

I must admit the Arm is a more logical choice than the AVR. If only because you get more power and it is multi sourced. Providing a degree of insurance and competition to reduce costs.

I don't feel that these were the reasons for ending up with the AVR though. Most folk who are not coders break out into a cold sweat as soon as you ask them to write some (However trivial). They won't attempt it because they think that they can't.

The arduino and environment lowered this bar to entry and a lot of folk who would otherwise not have attempted anything do.

Artists for example will not have a go with anything that they feel is not specifically promoting their art and its expresion. They would not learn an OS, learn the skills to set up a tool chain, set up an OS and tool chain and then eventually have ago at developing something. The perceived returns require too much perceived (and actual) investment.

Similarly if you actually explained in real terms to a potential application maker the hoops they have to jump through to get anywhere near trying their application (the bit they are really interested in the rest is strife) they would never start. A not insignificant number of makers start not knowing and by the time they have worked out how much they have to do to get started, have invested too much effort to back out without something to show for their investment.

The Arduino project (perhaps not entirely by intent, but it must have been a factor) addressed a bunch of this and savagely reduced the number of hoops that a would be maker needed to jump through to have a go.

This is evidenced by the Arduino's take up by those who are artistically inclined. These makers having learned just the one environment and language will not use anything else. Specifically because it is A what they know and gets them from A to B and because it is all that they know and their is too much learning of something that is'nt noticeably relevant to them to do do use something else.

We as technicians and embeded systems developers do not and perhaps can not easily appreciate this. Specificaly as most of us are conversant in a number of processors, toolchains and languages so one more makes no difference.


More to the point, If there existed an arduino like ARM (does'nt have to be the same or even pin compatible) and a development environmnet that supports this ARM which is similar to the arduino environment. Their would be an opening to move to the ARM.

Until such is found the general resistance to moving the projects principle processor from AVR to ARM (or any other processor) will be a touch like pushing water up hill.

Power, memory, pins, multi sourcing and even perhaps a marginal pricing difference are not actually why the AVR and specifically the Arduino is popular in this context.


If you can get something like this:-

Antipasto Arduino IDE for ARMDUINO

[www.liquidware.com]

And ARM board of your choice to play together nicely as well as port a sensible branch of the firmware, then demonstrate machine working.

Only then you may get folk to move in that direction.

Show the potential as a better, cheaper, done deal, that has a high degree of backwards compatibility plus no more obstacles to entry than the Arduino AVR boards and you have a chance.

Until then you are ploughing your own furrow. Albeit a better one.

---

Necessity hopefully becomes the absentee parent of successfully invented children.

aka47 Wrote:
-------------------------------------------------------

But I see people using Arduino Mega that costs $65. I think that is because people is looking for more flash/ram for more complex applications.

If instead we go to ARM, we get the same for less money PLUS a debugger, which is a must for the complex applications. This is my opinion.

And at RepRap project, many users don't touch on the firmware (users <> hackers). And RepRap is growing, I think more will be users and no hackers, so no need to worry to much with "friendly IDE and libs", instead a debuger is more important for the complex apps.

---

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]

... i bought the Arduino Mega for interest and some compatibility.

From older projects i have eval-boards, IDE's and some usefull stuff for PIC, C51 and other processors, but with the Arduino it's more fun than with the 'serious' hardware and IDE's

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Yup more arguments in favour of an ARMDUINO

---

Necessity hopefully becomes the absentee parent of successfully invented children.

So why don't we go with ARMDuino Leaflabs solution?

---

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]

so has much as i hate to say it, sounds kinda like the arduino team would benefit from trying to support the armduino in some way.

i can see your argument for the debuger, but at the same time has a fairly new person to embedded electronics i do like it for what it is right now, easy for me to learn, and if it dose not stay that way to some degree, that will just turn allot of people off the project.

there are allot of sides to this argument, and i can see many of them, but so far to me the arduino mega is has close to a middle ground has i can find. for price, ease of use, and memery/speed.


though faster would be kinda nice

---

[mike-mack.blogspot.com]

> there are allot of sides to this argument, and i
> can see many of them, but so far to me the arduino
> mega is has close to a middle ground has i can
> find. for price, ease of use, and memery/speed.

Arduino Mega is to much expensive. If money was not a problem, then we could use many of it, but we know that electronics of RepRap is an expensive part of the total.

And do you need to hack the RepRap firmware? -- I think almost everyone just flash the bin file, or I am wrong?

Edited 1 time(s). Last edit at 03/31/2010 01:53PM by casainho.

---

---
New cutting edge RepRap electronics, ARM 32 bits @ 100MHz runs RepRap @ 725mm/s:

[www.3dprinting-r2c2.com]

A interesting spin on this is a blog entry that I stumbled across "Why I hate Arduino" who articulates more why Arduino is a good home for reprap with his reasoning why it is popular.

[fourwalledcubicle.com]

How ever given all this discussion I think it is time for a new base design.

Given that chips come and go from production. The new XMega chips have a larger series of chips that can do intrinsic USB.

[www.evilmadscientist.com]

So lets define what should be in a base design with the emphase on modular?

My suggestion would be the following:

1. Native USB serial
2. SD card channel (more on this later)
4. Serial port buss to communicate to other boards or slave processors.
3. Dual stepper channels (on board stepper chips)
4. Dual themistor read channels
5. Dual heater outputs/DC motor drivers
6. Misc digital I/O for say End Stops or rotation monitoring.

So a typical configuration for mendal would be two boards.

First board handles X&Y axis's and heated bed
Second board handles Z axis and the first extruder

Extra boards as necessary.

SD card is hardwired in, not changable. It's only purpose is a run repository, no firmware overhead for fat or ntfs you just have fixed size storage slots for print jobs.

With a direct USB serial interface you can have a terminal style escape command structure for reading and writing the storage slots, selecting slot x to replay as if it is comming from the host, etc.

GCode is replayed from a SD storage slot and also sent via the serial port buss to all the other boards. Functions that are on board X are acknowleged by that board via the serial port buss to the primary card. I.E. only the board that understands the command responds.

Edited 1 time(s). Last edit at 03/31/2010 04:52PM by freds.

Hahahahahaha

This is funny.

(Been on the rum again, and it is good)

Look, the more you try to pin something for/against a particular processor the greater the likely hood that it will all end in a flame war with no consensus or progress.

There will always be adherents for any given processor that can find something (or more) that says why this particular processor should be the king of the heap.

Get over it.....

Your particular processor is only the best solution if and only if you are prepared to make it so...

I will say again..

If. And only IF you (just in case you missed the point I will emphasize this in upper case YOU, there did I shout this loud enough if not here it is again YOU) make it so.

Do it, I dare you.

Seriously, the world is full of wasters that want others to do it for them.

If you do it and it is the best solution then you are truly a hero.

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Necessity hopefully becomes the absentee parent of successfully invented children.

aka47, too wordy. I just smile and point at the sign:
[reprap.org]

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The other trick is to start pushing the various parties in the argument into creating wiki pages for their developments. Or I go and make a new forum.

You're right that if one party starts actually designing hardware, people start to work on it with him. But processor "beauty contests" never end amiably.

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

Oh I agree with the beauty contest comment.

I guess was what I was more trying to advoke was new processor for a lower chip count that did direct USB communication (screw ethernet) where the communication is bursty (dump to memory card and walk away).

Another thought that came to mind is that you could directly clone from one board to another. I.E. DNA transfer (grin).

Also given hubs and USB you could in a micro shop drive a number of machines from one PC and they could be as verbose about their current state as they wanted back to the host PC. So the USB becomes the chaty user interface since you have to have at least one bloody PC!

i think you can run more than one reprap from a computer now, you just have to assign what port it is on, i remember seeing it in a video from a university

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[mike-mack.blogspot.com]