Open Source Ecology Forums

dorkmo

i think we should start designing a breakout board to replace the green reprap version we have been using. the current design underutilizes it so we could fulfil the need with something simpler.

Allen15

Which project are you referring to? Are you referring to the CEB Press & this board?
http://opensourceecology.org/wiki/File:Breakoutboard.jpg

If you can identify which parts of that board are used, and which parts aren't, it would be a good start to designing a replacement, since all of the files for that board are available off of the web. Oops... Looks like the Sourceforge link to download those files has vanished, and searching Sourceforge for all things Arduino doesn't turn it up at all... Guess that's another one that has gone the way of the Dodo bird.

Allen15

I was able to find https://github.com/reprap, which is now the official repository for RepRap files, so hopefully, the information would be in there, if needed.

dorkmo

heres the page http://www.reprap.org/wiki/Arduino_Breakout_1_4

problem is there is only one shop that sells it. and you have to buy all the parts separately. i need to ask william what wires are used for it. i know that 6 wires are for sensors. but i think they share ground, maybe power? the analog signals go into A0 and A1 you can see from the nice picture. also it looks like from the picture there are three resistor on a couple digital inputs or something. and an led or two. so i think thats around 8 plugs used if you merge the grounds into one, could be less if you had the resistors on the board.

heres the one that came from detroit that has mosfets mounted on it. http://opensourceecology.org/wiki/File:Driverboard.jpg

it could be based on that in general.

Allen15

I'm not looking for where to buy the boards - as they are supposedly open source, there is supposed to be a link to download the source files so that I could make my very own boards. Both of those boards don't seem to have links to anywhere to download the source files, like the eagle files or the gerber files for making them, but at least the 1.4 revision breakout board still had the (now dead) link to what I was looking for.

Open source isn't supposed to be about "here's another opportunity for you to go buy something else", but rather "Here's what & how we did this, see if you can use this information to also do, and perhaps do better, then you can return with ways to improve our design"

THAT'S the part that is missing. I could go shopping for parts all day long for closed source stuff - they'll be happy to sell me lots of gadgets 24/7... Telling me how to make my own is supposed to be the open source difference, and as this is/was open source, I'm looking for the original design files for this version, so that I can modify the design to better fit with what you were asking about.

I already have the Eagle design software, and I already know how to design circuit boards, and I already know how to chemically etch my own boards on small scale. I want the data files for THESE boards to alter them..

Allen15

I've found the Sourceforge repository that contains the information for that board (it isn't in the current version zip download, it's in the archives) http://sourceforge.net/projects/reprap/files/

Now, please explain which parts you don't need?

dorkmo

here are the pictures of the current set up http://www.flickr.com/photos/brokensidewalkfarm/sets/72157627652815539/

you can see where whole sections of the green board are not utilized in this application

we dont have any of the design data files as far as i know for the milled board.

just these pictures:

http://opensourceecology.org/wiki/File:Drivertraces.png

http://opensourceecology.org/wiki/File:Driverschematic.png

what do you think the best path forward is with the data we have?

if we need to we could get one of the guys at the farm for more details

Allen15

I'm going to go to FeF this weekend. I will try to collect more information, but because I found the Sourceforge repository for this board, I now have all of the design files needed to recreate it from scratch, or modify it do suit any other purpose.

See the Sourceforge link above; there is an 'other versions/files' section below the most current version download, which will take you to all of the previous revision files of all of the related boards. At this point, I just need to know which functions are deemed to not be needed to remove them from a sample for presentation.

To clarify, I have all of the design files for the 1.4 version breakout
board (upper link), and can change that one at will.

The 5 solenoid driver board (lower 2 links) is the one that I was asking about
where are the design files for originally. That was one that was being made by a
Detroit FabLab, and is no longer stocked by the normal sources, and also is
the board for which I was first trying to find data files for.
Hopefully that information could be obtained from the Detroit FabLab,
but I don't have contact information for them (yet).

dorkmo

as far as i know only marcin has been in contact with detroit, maybe chris too, not sure

from the pictures, this is what i came up with for all the connections to the rep rap board:

A0 - sensor

A1 - sensor

digital 12 - led w/ resistor

digital 13 - led w/ resistor

ground - to 12v? and detroit board?

VIN - to 12 v? and detroit board?

5V - sensor

ground - sensor

what do you think?

have fun at the farm :D

DavidIAm

If I want to add five sensors, 3 of them analog and two of them digital, combined with 2 or 3 other actuators/relays/solenoids on the system, is your 'pared down' board going to be insufficient to the purpose?

Its *okay* to have spare capacity, isn't it? Is this premature optimization, what is harmed by having too many connection points on the breakout board?

dorkmo

oh yeah! i forgot about your pressure sensor idea... what i had in mind definitely wouldnt work :/

my main deal is that the reprap board is harder to make. the detroit board can be a homebrew, supplemented with generic parts.

i think if we get good at designing boards that are easy to make we could have custom boards for each style of machine.

also we're maxed out at 5 mosfet transistors with the detroit board, so a new board would be needed there to add more automated motion.

i think in general the reprap is good for experimentation with new equipment but doesnt make sense in the long run for production. maybe we could have a standard shield design for each different number of I/O devices for the machines. like a small board for 2 sensors counting up to a 8 sensor board or something like that. what do ya think?

DavidIAm

I think those kinds of optimizations matter alot when you're a for-profit enterprise trying to get the cheapest possible parts into the system. This is a standard way for people who do pcb and board design to think - their designs get replicated tens of thousands of times. naturally even a small cost savings is going to be major.

But we aren't trying to make the optimum amount of money on the system. (I think)

We're trying to supply an open source, extensible, experimentable construction people can use.

But we still need to consider our supply chain - 'hard to make'? It *looked* like a board with a bunch of through-holes and soldered-on screw terminals to me - perhaps not the most trivial of operations to fabricate, but still not particularly high up the list - does it actually need transistors, capacitors, resistors, or other surface mount tricky components? Or is it just through-hole soldering?

dorkmo

there this but we'd have to fab it our selves http://www.sparkfun.com/products/10305

or this but we'd have to make two http://store.makerbot.com/pwm-driver-v1-1-kit.html

DavidIAm

I'm confused. Are we talking about the breakout board or the detroid solenoid driver board?

dorkmo

you brought up that you needed three more actuators or solenoids, the detroit board can only do 5 at this point. so we'd have to buy the boards if we dont design a new one, so i though i'd start looking for arduino shields that would work off the shelf.

DavidIAm

I wasn't thinking that the actuators would necessarily require that much current - I'm as likely to hook up secondary relays to activate the main solenoids, this just doesn't seem to be a particularly critical level of worry to me. (but then I have experience with such electronical things)

I'm concerned about the breakout board being reduced in functionality. the niggly detail of being able to step up current for actuation of whatever isn't of particular concern to me. I can make a detroit-like amplification circuit with a few components, a soldering iron and electrical tape. I can't tap into the io lines of the arduino shield bus nearly so easily.

Is it possible to use a design like the detroit to stack - five per layer? I dunno.

But I'm concerned about having easy access to the io pins. their current constraints I can work with.

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