31–40 of 60 posts
Can anyone share any details about one of those laser wood cutters? Costs/Materials/Brands/Issues etc. for a hobbyist?
Otherwise, you're talking $5k and up. However these guys are cheap and fast if you want to farm it out: http://www.pololu.com/catalog/product/749 (I don't work for them, and I'm not an affiliate, just a happy customer)
Can anyone share any details about one of those laser wood cutters? Costs/Materials/Brands/Issues etc. for a hobbyist?
With all these open cell phone stacks: what do people do about IMEI? Isn't modifying IMEIs illegal in many countries? Or is the IMEI already programmed as part of some module from the factory and thus there's no need to change it? EDIT: Whoops. I did mean IMEI and not ESN. I've edited this post.
I'd imagine it works similarly with ESNs, but I have no experience there.
Can anyone share any details about one of those laser wood cutters? Costs/Materials/Brands/Issues etc. for a hobbyist?
Unfortunately, its quality was so terrible, it was little more than a box of parts. I had to build a new stepper driver and run it from MACH3 to get any results out of it. I also had to replace some "greased rail" style bearings with linear ball bearings to get decent accuracy.
The one they've got at MIT probably says "Epilog" on the side and costs somewhere between your car and your house.
Edit: I generally cut "luan" plywood 1/8" or thinner. It seems like about the thickest I can handle. 1/16" veneer gives me the best results.
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Actually what these guys don't mention is that the Raspberry Pi is plugged into a relatively huge USRP, because that kind of blows their whole "Look how tiny it is" PR out of the water.
+5. You can run the whole stack on a router. It's basically doing call control for a couple of channels. The heavy lifting is done in USRP.
OpenBTS is a software defined radio and really does most of the processing in software. The USRP provides the radio interface, up/down conversion between baseband and carrier frequencies and the analog/digital conversion.
The USRP just sends/receives those samples without caring or knowing about GSM. Samples are processed in software on the host, where the GSM stack is implemented.
There's other hacks(http://www.youtube.com/watch?v=xFjVcxMpA6c) where you can just use a couple of phones as the transceiver instead of the USRP.
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Sure, but it would be a cool project to build up a nice phone environment using this module. If anything, this would be more akin to saying "I'm using hardware features on my microprocs to do this neat thing". Not amazing engineering. On a related note, does anyone know if we can get these modules to do data? Or if there's a cheaper version of these modules?
The GSM module supports GPRS and TCP/IP via AT commands[1] so it should be possible to get some data going. [1] https://www.sparkfun.com/datasheets/Cellular%20Modules/CEL-0...
For example device, see http://www.windowsfordevices.com/c/a/News/Opensource-hardwar...
For PPP info, see http://ernstagn.home.xs4all.nl/GPRS-HOWTO/
[EDIT:] It's been a while, but Telit was also pushing their embedded python interpreter pretty hard back when I was into all of this. I had need for an embedded micro for other parts of my application so I never bothered too much with it, but it looked pretty interesting.
Hardware: https://github.com/damellis/cellphone2hw Software: https://github.com/damellis/cellphone2
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Sure, but it would be a cool project to build up a nice phone environment using this module. If anything, this would be more akin to saying "I'm using hardware features on my microprocs to do this neat thing". Not amazing engineering. On a related note, does anyone know if we can get these modules to do data? Or if there's a cheaper version of these modules?
I did a quick peek at their electronics schematics. Well, believe it or not, but it looks like designing a laser-cut custom wooden case for this phone took much more effort than the electronics part. So, returning to my analogy: you are building a DYI PC because you laser-cut a custom case for the off-the-shelf parts you purchased. If this is the level of DYI to be amazed of on this site, I'm completely confused.
More generally, I am a believer in the idea I first read from Clay Shirky that as more people get involved in an area average quality goes down but innovation goes up a lot as you get lots of people trying lots of new things, which in the end is only goodness. Except, perhaps, for those that prefered it remain elite so they could feel special (not saying this is you, but I see this attitude in a lot of pioneers in areas that later become more mainstream).
"Cellular connectivity is provided by the SM5100B GSM Module...". Meh. No way a DYI. It's like you assemble your desktop PC from pieces like motherboard and power supply and say that you built a DYI PC.
Do we say that Apple doesn't build computers themselves because they buy the CPU from Intel? Or because they use Qualcomm transceivers (and lots of other off-the-shelf components) in their phones? On the other hand, we probably wouldn't say someone made a phone if they just put it into a different enclosure.
I can say that I spent a lot of time selecting all the components, putting together the schematic, routing the board, and writing the UI software. (All of that took a lot longer than laser-cutting the case.) Of course, it probably took a lot more work than that to create the GSM module. But that's also true of the microcontroller I'm using, the LCD, even the battery. Just about everything is built on top of the work of others (see the Toaster Project for an example of how hard it is to do otherwise).
Interestingly, this critique hasn't really come up from the people I've worked with to build the phone. I explain the function of the GSM module (and the rest of the components) but after putting it all together, people don't seem to think of the phone as just a box for the module -- in part, I'd argue, because they realize how many other things are in there too.
Again, though, there's a fundamental question here that I'm trying to explore with my research: what does it mean to do it for yourself?