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Topic: What breakout do you need/want? (Read 105429 times) previous topic - next topic

Re: What breakout do you need/want?

Reply #15
Wow they carry lots of breakoutboards!

Inspiring site ;) i'll take a look there

Re: What breakout do you need/want?

Reply #16
i have an old radio shack usb to serial cable, it was sitting in a box for the last few years because the drivers did not work in vista/windows7 64 bit, i ended cutting the board out of the cable and started looking up parts. after looking up the prolific chip i realized i could remove the eeprom and use the prolific drivers in win7. it kinda upset me cause all the parts on the board are really cheap.
anyway I'd love to see a sub $10 usb > rs232 adapter. ill prototype it if enough people are interested.

Re: What breakout do you need/want?

Reply #17
There is a MCP2200 breakout on its way. The MCP2200 is a low cost usb to serial made by Microchip. As a plus it has also some extra GPIO (can be used to drive a couple of status leds).

Here is the link to the datasheet : http://www.microchip.com/wwwproducts/De ... e=en546923

Re: What breakout do you need/want?

Reply #18
how about adding a rs232 converter chip to the bottom of the board?
populating it could be an option for the end user.

Re: What breakout do you need/want?

Reply #19
[quote author="sqkybeaver"]
how about adding a rs232 converter chip to the bottom of the board?
populating it could be an option for the end user.
[/quote]

I think rs232 is (almost) dead, since every new device has USB and no rs232. Even if a device has serial (like many routers for example) the port is 3V3 or 5V TTL.

Re: What breakout do you need/want?

Reply #20
We can make a USB to full rs232 for a few bucks if you like, no big deal. That's a super easyroject.

@ahri - are there a number or collection of riprap boards that we could provide at great prices?
Got a question? Please ask in the forum for the fastest answers.

Re: What breakout do you need/want?

Reply #21
I was planning to design and build myself an OLED breakout board, something good for breadboarding. I have some reference designs but ddn't had time to do any work on them. I can pass on the results to here for prototyping/manufacturing?

Re: What breakout do you need/want?

Reply #22
It depends on the demand. If it's common parts, and lots of people are interested ( 20) then we can produce it no sweat.
Got a question? Please ask in the forum for the fastest answers.

Re: What breakout do you need/want?

Reply #23
excellent point Sjaak. i guess ill have to keep and old pc around just to use my old kantronics tnc. i guess the only thing keeping it alive are proprietary systems that hide the phy specs. ive seen rs485 used in non standard ways lots of times.

Re: What breakout do you need/want?

Reply #24
[quote author="ian"]
@ahri - are there a number or collection of riprap boards that we could provide at great prices?
[/quote]

well, it is not "that simple" :D

the reprap machine requires
 - g-code processor
 - 4+1 stepper drivers
 - 1+1+1 heater controllers
 - X aux ports

The first boards were around some small pic and those are not used any more, then there is a whole set of boards that have "each board separately" so you had
 - arduino (initially the smallest one, then sanguino (ATMEGA644P) and now arduino mega) for the "brain"
 - one stepper drive on separate board, initially this was L297+L298, then those pololu alegro boards
 - separate board for extruder (1stepper+1heater) with arduino
all boards linked using RS485 to the "brain" and "brain" linked to PC via rs232->ftdi->usb

There are also few versions of "all on same board" that ppl sell.

There's bunch of places one could by these and prices are more/less ok .. the only 2 boards ppl mostly buy today are the
 - stepper driver lot of ppl go for pololu from link I provided but if for similar price one could pack "better board" (one that would for e.g. allow for both decay control as well as current control, and with proper cooling as these chips heat fast and mounting cooler on the 5x5mm chip ain't simple)
 - extension board for the arduino mega that would take 4 stepper drivers + thermistors + relays or fet's to control heating elements

- there are also few closed source solutions that are irrelevant

What is currently in the "process of being developed" are completely open source stand alone electronics. There are 2 being developed in parallel, on guy (I think south america) is making a ARM CortexM3 version of the original set of boards and he has the pcb making process already agreed somewhere and he is working on the software attm - he will have everything on the single pcb, and there's another set being attm worked on by me and some German guy's that is attm based on "break boards" :D that could/should eventually have a "single board" solution too. Attm it works like this
"UBW32 board is the brain of whole operation (original firmware thrown away of course) is connected to the motherboard (attm this is a solder-less breadboard). Motherboard has only SD card directly on board, and it has sockets for
 - 6 stepper drivers (attm pololu)
 - thermal controller (I have not done this but I believe this will be a small pic with 5 ADC for reading thermistors and 5 digital outputs to control relay/fat's with some pid with a i2c+1 line for communicating with pic32mx - attm I control temperatures directly from pic32 with bang/bang method - no pid)
 - Input module (attm I use 7 buttons, but want to replace 4 of them with a jog, and want to be able to have them on "external board+cable" so I can position them for easy access)
 - Outpit module (attm I use OLED on spi controlled directly from pic32 but the idea is to be able to use different modules so 16x2 or 20x4 char display for e.g.)
 - communication module (ethernet, wifi, bt, xbee .. whatever - some standardized port towards comm module - this is not close to be done)

So the idea is for it to be modular .. but I don't believe the design will be done before and of january ... here you could for e.g. make motherboard + some of the modules, and later a single board solution could be made (with one set of parts just placed on single board) ... but, this all need to be design first... the good thing about the board is that the software is not for reprap only, it executes standard g-code and works as a stand alone printer/milling machine so you can use sd card to place files directly on your computer and do not have any comm between printer and computer, or you can send file via usb (again to sd card) and initiate printing (you can of course move stuff from pc too, control heat etc..).. so the same board can be used for any engraving, milling, cutting machine .. I already tested if it can replace electronics of a "very bad laser cutter" and we successfully cut A3 sheet of acrylic that original board cannot cut (the pattern is too complex and must be split into 2-3 passes with the original pcb) ...

Re: What breakout do you need/want?

Reply #25
it should be super easy to build a basic 3 chan stepper driver with heater on board. maby you could post a link to what you have in mind?

Re: What breakout do you need/want?

Reply #26
[quote author="sqkybeaver"]
excellent point Sjaak. i guess ill have to keep and old pc around just to use my old kantronics tnc. i guess the only thing keeping it alive are proprietary systems that hide the phy specs. ive seen rs485 used in non standard ways lots of times.
[/quote]

It wasn't my intention to let you stick with old hardware.. Serial ports aren't that common anymore. In my job I see lots of devices that used to be programmed by serial (rs232) move to ethernet or USB. Back in the days when it was still common it was nearly impossible to get a laptop with native (well PCI based :)) serial port and USB convertors were buggy (about 5 years ago). They also gave problems because they occupy high comport numbers (COM5 and up) and that propriatary software couldn't cope with that either.

Luckily those systems move more and more into the future :) (slowly) :)

Re: What breakout do you need/want?

Reply #27
ideally in 1985 the should have known that usb is the future, but they instead went with a DB25 rs232. it is just a problem for me cause i still use AX.25/packet radio. after 25 years it can still handle current standards. and that is why i still use it!

Re: What breakout do you need/want?

Reply #28
[quote author="sqkybeaver"]
it should be super easy to build a basic 3 chan stepper driver with heater on board. maby you could post a link to what you have in mind?
[/quote]

I already made bunch of them .. I know they are not "complex" to make .. but single channel driver is better as then ppl can use as much as they want (for e.g. mine machines use 5 channels) .. for e.g. A3979 is a nice chip to work with .. not too high pitch but the "Exposed sink pad" is the problem, you must solder the chip to the bottom properly and use vias to move the temp down + you want to add some heat sink on top of the chip ... you want to add small pot for both current and for pfd control...

second very interesting chip is A3985 that require external h-bridge, combining this chip with strong full bridge all properly cooled would be great solution - maybe there are some transistors that are same height as A3985 so a single big heat sink can press them all to make a compact board ...

those are just ideas ... reprap community already have a bunch of boards available... here are some:
- v1.0 v1.1 v1.2 L297+L298
- v2.0 v2.1 A3977 based, no proper cooling
- v2.2 v2.3 [url=http] v2.3 sold by makerbot A3982 based, no proper cooling

there's also integrated board that puts everything on the same pcb, stepper drivers are around hitachi chip iirc ...

but I can't talk for the "community" ... many things I believed I knew about reprap community came to be false when put to test ... it is very diverse bunch, some try to find solutions that are "ultra cheap" and reliability and quality is second to that, while others require quality above all ...

Re: What breakout do you need/want?

Reply #29
My 2c :o)

Maybe a full human interface board :oP , well at least few switches, capacity switch (touch switch), few leds, few potentiometers ...

Maybe a cute CPLD board...
I used few time some xilinx xc9572 with pleasure.
My prototypes problems were packaging and number of io pins packaging ...
It should be better than this :oP