Author Topic: Community Project - Module Housing (Read 9862 times)

Trumpkin · « **on:** April 22, 2009, 06:49:43 PM »

Here are my ideas for housing of modules for the community project:
#1 (see cube.png which is an example of a servo module) Each module is housed inside a cube with four metal plates on each side for power and the i2c bus. problems would be:
hard to keep all plates in contact
plates could be easily bridged
#2 Same as #1 but instead of plates you could use 4 bolts that would supply both a mechanical connection between the cubes and an electrical connection.
I think It would be really cool if we could build the housing for the modules in such a way so that you wouldn't need a chassis. Does any of this make sense or am I going off in the completely wrong direction? Feel free to post your ideas in this thread.

SmAsH · « **Reply #1 on:** April 22, 2009, 06:54:19 PM »

i thought we were just having boards that are stackable via standoffs, i didn't know about the block thing? i don't really think it would be logical as there are too many ways something could go wrong with this, ie. someone places block upside down and boom, gets placed on a piece of metal accidentally, the robot goes over bumpy terrain and they come apart... in general this is an alright idea but i really cant see it happening because of some peoples weird requirements.

Ro-Bot-X · « **Reply #2 on:** April 22, 2009, 10:43:47 PM »

I like the idea of having inteligent cubes that house a microcontroller, a motor, sensors, perhaps even a small LiPo battery. Teoretically we could use them to create more complex robots, eventually something like the Replicators. However, technology is far away from that. Something with limited movement and conectivity can be created, but for now conectivity is an issue. Most of the designs I've seen use a second smaller motor for locking the cubes together.

Get a servo, sandwich on one side a LiPo, on the other side a distance sensor, light sensor or whatever, mount it in a lightweight cube, have the contacts like circles on the sides something like this: center - power for charging, next circle SCL, then SDA, then at the exterior GND. This will leave the corners for locking cubes - need some locking mechanism ideas here. The microcontroller can be a tiny85.

Now these cubes or whatever shape they'll be are appendages. There has to be a brain cube, and perhaps a vision cube, but they can be fuzed together in one. Other cubes can be wheeled cube, gripper cube... Also some cubes may bend and others rotate.

This way a complex robot can be built from this cubes and programmed to re-shape itself when it is appropriate, it can walk, or drive, or both...

madchimp · « **Reply #3 on:** April 23, 2009, 01:22:01 AM »

As neat as the cube idea would be.. I think it would drive cost way up and make it less flexible. I think if you guys want to do the cube idea awsome, you should go for it but it should be a another project based on the modules created from this project. I do like the idea of having some sort of plastic housing though. I can't remember where or which thread but someone brought up the idea of using rj45 connectors or something similar between the modules which I though was a pretty neat idea. I think having plastic boxes that can be connected with some sort of basic plug system would be far less intimidating for new users. I also think the modules should be designed so they can be used without the enclosures as well. If this project were to make a certain style enclosure popular and inexpensive it might also get other people to design their boards to fit in them, creating a standard for board sizes. What I kind of envisioned for the housing would be a three piece unit the top, bottom and the sides as one unit. Then if you wanted to stack say two modules in the same location on your robot you use one bottom two side units stacked and then the top cover. I also think using the axon as a basis for the size of the boards is a good idea, because it's already out there. The axon could be considered a full board then you could have variants on that like a quarter board half board and even boards one and a half times the axon. (also from someone else somewhere in the threads) If we do that then we already have the sized figured out hole placement is already sorted and the dimensions are already posted on this site. I'm sure I left something out but I'm getting tired and I just hope what I wrote is coherent lol.

SmAsH · « **Reply #4 on:** April 23, 2009, 05:41:35 AM »

this is an alright idea but i have to agree with madchimp about the expenses, i think it if were to do this at all we should build the modules first and if they're popular take a look at boxes.

dellagd · « **Reply #5 on:** April 23, 2009, 06:27:01 AM »

Quote from: Trumpkin on April 22, 2009, 06:49:43 PM

Here are my ideas for housing of modules for the community project:
#1 (see cube.png which is an example of a servo module) Each module is housed inside a cube with four metal plates on each side for power and the i2c bus. problems would be:
hard to keep all plates in contact
plates could be easily bridged
#2 Same as #1 but instead of plates you could use 4 bolts that would supply both a mechanical connection between the cubes and an electrical connection.
I think It would be really cool if we could build the housing for the modules in such a way so that you wouldn't need a chassis. Does any of this make sense or am I going off in the completely wrong direction? Feel free to post your ideas in this thread.

magnets?

Asellith · « **Reply #6 on:** April 23, 2009, 06:53:54 AM »

The beauty of this project is just like an open source software project it can be taken in several directions by different people. I think if someone was to find a premade mass manufactured module housing then great let us know it will go in the documentation. If someone wants to design a stackable custom enclosure that clips together and has either space for ribbon connectors to the different boards or as was mentioned earlier something like an RJ12 or RJ45 connection to link them then great. A good enclosure design could help but shouldn't be mandatory.

A good design would be something as modular as the modules (that sounds weird) Anyway. If you design the enclosure to clip to each other in every direction then it could get really cool. So you can have a grid of 4 modules all clip together in a square that then by flipping over and screwing the modules in upside down will let you stack another set of 4 on top to "close" the box. That might be really cool.

HyperNerd · « **Reply #7 on:** April 23, 2009, 10:48:26 AM »

Has anyone seen the Servo Erector Set from Lynxmotion? What if we made some modules that fit the hole pitch on those parts, so the frame of the robot could be made very easily, and changed if necessary.
I agree with the idea of RJ45 connectors on the modules, as that gives 8 wires to use for whatever purposes need be. The Lego Minstorms NXT is a perfect example of a module based system, and I love it so much I bought 2 kits!

-HyperNerd

SmAsH · « **Reply #8 on:** April 23, 2009, 03:45:05 PM »

this is actually starting to seem like a really good idea to me, but if this is for noobs and we have a lipo battery that can easily be connected wrong.... if we are going to do this we need to make then polarized otherwise they could be screwed over in 20 seconds.
with the plate idea, would all four sides be the same, ie. power- power+ i2c i2c?
but what about all the unused ports on the axon? if we encase the axon in a case the user can use any of the axons I/O ports. this may drive hobbyists who are more advanced away from it.
would it be appropriate if the axon was on top of one of the boxes using standoffs and the I2C cable running into the box contacting the plates, that way you can still access the programming pins/usb and all the I/O.

dellagd · « **Reply #9 on:** April 23, 2009, 06:02:51 PM »

my idea was to have the 4 plates and magnets like this
it would hold it on and also because of the 4 plates the battery cant be hooked up wrong.
we would also have lots of diodes for protection

Razor Concepts · « **Reply #10 on:** April 23, 2009, 06:07:08 PM »

Isn't this like sort of like designing the shape of a car before actually figuring out how to fit all the engine and electronics in it?

SmAsH · « **Reply #11 on:** April 23, 2009, 06:20:51 PM »

yep, that's pretty much it. as i said though, i think we should design the modules and get them working on pcbs before thinking about this.

dellagd · « **Reply #12 on:** April 23, 2009, 07:03:58 PM »

think we should start a new post for designing the PCBs and electronics?

SmAsH · « **Reply #13 on:** April 23, 2009, 07:06:40 PM »

yes, but shouldn't some of these topics be in other sections? like this one in mechanics?

dellagd · « **Reply #14 on:** April 23, 2009, 07:11:48 PM »

yes, and the PC board topic in electronics

SmAsH · « **Reply #15 on:** April 24, 2009, 12:34:52 AM »

i was thinking about some ideas for this today and was wondering about the flexibility of these "boxes"... will there be any way to change something on the pcb if something were to go wrong? or if we needed to reprogram the chip? anyway, i was thinking of a hinge system with some kind of catch so the lid wouldn't just fly open any old time, what do you guys think of the idea to be able to open the boxes to change/repair the modules?

Trumpkin · « **Reply #16 on:** April 24, 2009, 07:58:18 AM »

I was planning on the boxes being able to open. Just a hinge on one side and a screw on the other should do it.

SmAsH · « **Reply #17 on:** April 24, 2009, 03:17:08 PM »

yea, that'll be great as it allows people to do mods/put new electronics in their boxes and let them connect up.
and dellagd, to your pic a few posts back, there is power bus down the bottom then there's also the colored dots... do they both carry the bus?

dellagd · « **Reply #18 on:** April 24, 2009, 04:05:30 PM »

the 4 circles with blue and red are magnets
the + and - are positive and ground

SmAsH · « **Reply #19 on:** April 24, 2009, 08:55:42 PM »

ahh i see how it works now! but i think there should be a way that prevents you from physically plugging them in the wrong way, like a socket in each corner with a distinctive shape to it.

dellagd · « **Reply #20 on:** April 25, 2009, 08:49:14 AM »

I see what u mean. give me a sec I'm skteching it up.
like this?

SmAsH · « **Reply #21 on:** April 25, 2009, 03:46:45 PM »

well, not the plates themselves but more a bolt that will sit there. but is removable by just pulling.
attached is a general image of what the boxes will look like.

dellagd · « **Reply #22 on:** April 25, 2009, 05:12:28 PM »

cool!

looks like a good idea to me

Trumpkin · « **Reply #23 on:** April 25, 2009, 06:20:00 PM »

Quote

attached is a general image of what the boxes will look like.

Don't mean to be rude but if you think about it that won't really work since you could only plug male into female, it doesn't look very professional either.

SmAsH · « **Reply #24 on:** April 25, 2009, 06:22:42 PM »

gahh! just an idea... brainstorm people! im generally not too good at designing things

dellagd · « **Reply #25 on:** April 25, 2009, 08:01:22 PM »

this project is still in the designing stage. all we are doind here is ideas. nothing is final.

HyperNerd · « **Reply #26 on:** April 26, 2009, 06:35:58 AM »

I think Trumpkin has got a point...
The connectors could only be plugged in one way round, so some modules would end up being the wrong way round.
(Anyone remember the wooden train set you played with as a kid, and how annoying it was when you ended up with two ends that had the same connector on them)

So, here is my intended (although complicated) solution:
The module is a box on its own. On the side of each module is a ring of 8 spring loaded protrusions, 4 contact rings, and a pivot point dead in the center. A plate / circuit board consisting of the magnets, I²C connection plates, and a matching ring of contacts on the back. 8 holes are drilled in the board, which line up with the 8 protrusions on the module. The board is then mounted to the pivot point.
This maintains the polarised nature of the magnet / plate combo, but allows the module to be rotated and locked at 45^o intervals, so it would not face in the wrong direction.

Confused? I don't blame you. Here are some sketches to clarify.

-HyperNerd

dellagd · « **Reply #27 on:** April 26, 2009, 06:53:53 AM »

I like it
the more flexible the better

hazzer123 · « **Reply #28 on:** April 26, 2009, 07:09:57 AM »

Maybe making these things would be easier if they used simple magnets to connect physically together. If the plastic was transparent to IR light, then a simple asynchronous IR link could be made between neighboring blocks.

I think it would be prettier and simpler. We are electronics guys after all, try to reduce manufacturing complexity for electronics hardware.

No physical problems with connection orientation and male/female connectors either.

HyperNerd · « **Reply #29 on:** April 26, 2009, 12:36:18 PM »

That is a very ingenious idea, but what about power connections?

Anyway, if IR is used, here is my contribution to the hardware/programming aspect of all this (the word 'node' may be used interchangeably with 'module' or 'block'):
Hardware:
Each node has a unique ID consisting of a 8-bit type code plus an 8-bit ID number, resulting in a 16-bit word which is unique to that node only.

Software
Reset
Host controller sends an 'ID' command to the modules connected directly to it, which then repeat this process to all the modules around them. (I am assuming all 6 sides of the cubes can communicate)
Each node builds up a code of all the nodes around them, and sends this to the node who issued them the 'ID' command. This results in the host controller knowing exactly which nodes are connected, and where they are in relation to each other. This map is then forwarded to every node in the network.

Message
When a message needs to be sent to say, the motor controller node (identified by it's unique 16-bit ID), the host uses a wavefront pathfinding algorithm to detect which nodes the message must pass through to get to it's intended target. This is a possible message structure:

[header]
source node ID
destination node ID
[body]*message data*

When the message passes through a node, the node sends back a confirmation byte to the sending node, following the same path as the original message.

Error
If a node is removed from the network (disconnected), when a message is to / through that node, the sending node will not receive a confirmation byte from the removed node (obviously), and will therefore send a command to the host controller, telling it to rescan the network, so a new layout is calculated.

What do you think guys?

-Hypernerd

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Author Topic: Community Project - Module Housing (Read 9862 times)

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