64K is still quite a lot! Embedded Programming Microthread

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > 64K is still quite a lot! Embedded Programming Microthread

Kire: Aug 25, 2006

I'm trying to use my beaglebone, but I'm running in to trouble just trying to install emacs. I've been following this tutorial:
http://www.gigamegablog.com/2012/01/29/beaglebone-linux-101-configuring-angstrom-linux/

and I'm trying to use "wget https://www.angstrom-distribution.org/feeds/2011.03/ipk/glibc/armv7a/base/emacs_22.3-r1.6_armv7a.ipk" but linux keeps telling me "wget: bad address 'www.angstrom-distribution.org'" and since I can't ping any IP addresses from the command line I assume my beaglebone isn't accessing the internet properly? The funny thing is that opkg update and opkg upgrade seemed to work just fine which I believe require accessing the internet. What am I doing wrong?

Edit: Separate question, is there a C/C++ library that would let me do things like "pinMode(usr_LED0, output);" so that I don't have to use Java/Python/Cloud9, but could still control the IO pins really easily?

Edit: vvvvvvvv no luck, quotes didn't help.

Kire fucked around with this message at 04:20 on Jan 31, 2013

# ¿ Jan 31, 2013 04:16

Adbot: ADBOT LOVES YOU

# ¿ Apr 27, 2024 17:15

Kire: Aug 25, 2006

The AVR Dragon is a beautiful board, and those stencils are pretty classy. I use one in my lab and yes it is a pain in the but having to manually wire up all of the JTAG pins every time :-(

# ¿ May 2, 2013 23:52

Kire: Aug 25, 2006

I'm trying to write an img of Ubuntu onto an SD card for my beaglebone, but since I'm doing this on Windows I can't easily just sudo apt-get whatever package everyone recommends. I tried downloading an "Omap4" img, but that just causes my beaglebone to never turn on its heart-beat LED, and my WinXP machine thinks that it has "found new hardware" every 10 seconds with no end. I'm trying to follow this tutorial: http://embeddedprogrammer.blogspot.com/2012/10/beaglebone-installing-ubuntu-1210.html and I'm downloading these 12.04 imgs from https://wiki.ubuntu.com/ARM/OmapDesktopInstall . What am I doing wrong?

I even got the file located at http://rcn-ee.net/deb/rootfs/quantal/ubuntu-12.10-r2-minimal-armhf-2012-11-29.tar.xz as shown in the tutorial, but that doesn't have an img in it! Instead it relies on a shell script to create the img, and I can't do that in windows.

When I get a root file system like at http://eewiki.net/display/linuxonarm/BeagleBone#BeagleBone-Ubuntu13.04%28Raring%29RootFileSystem , what can I do with this on Windows?

Edit: I should mention I had no problem with Angstrom for months, but I want to switch to Ubuntu for security and increased usability.

Kire fucked around with this message at 00:11 on May 9, 2013

# ¿ May 8, 2013 23:21

Kire: Aug 25, 2006

Captain Capacitor posted:

Virtualbox?

I may need to create the img on a linux computer at my office, but I don't understand why the Omap imgs don't work.

Cygwin wasn't any help.

# ¿ May 9, 2013 00:04

Kire: Aug 25, 2006

Delta-Wye posted:

Of course, when they go to do 30-45 analog reads in a row (the multiplexor guide said it would work!!!!!) and find out that it's hellishly slow they lack both the ability to recognize the problem (ADC reads take a long time) or the solution (kick them off and use an ISR to grab the data instead of spinlocking and waiting).

Something I'm confused about with the ISRs on the MSP430 line of chips is if the chip only has one processor, the ISR has to be swapped in and the main program be swapped out for a while for the ISR to run, so it's not truly happening in the background like on a multi-threaded system, correct? So for this example of kicking the analog reads off to an ISR, that requires a multi-core or multi-threaded system to have any effect, right?

Are those terms multi-core and multi-threaded appropriate for talking about microcontrollers?

# ¿ May 11, 2013 16:29

Kire: Aug 25, 2006

evensevenone posted:

Uh you never have multiple cores and rarely have multiple threads (unless you are using some kind of crazy RTOS).

An ISR needs to be a super-fast little thing that just does something like copy the value into a buffer and return. Then your regular code can read the buffer on its own time.

As long as you keep your ISRs fast, it's like they're happening in the background but they really aren't.

That's what I thought. So Delta-Wye is saying that the ISRs should read the ADC output when it's ready at the ADC and then return it, rather than having the main thread poll it? I believe this assumes that the hardware supports activating an interrupt flag when the ADC output is ready?

# ¿ May 11, 2013 17:04

Kire: Aug 25, 2006

SnoPuppy posted:

I thought you had to pay for TI Code Composer unless you were using one of their dev boards.

TI still makes you pay for CCS even if you're using a dev board, I think. But they say the free version is limited to 16k programs, and the binaries I've uploaded to my Launchpad say they're 23k so I must be misunderstanding that. I've heard people say they don't like the ez430 Chronos watch because the free version of CCS doesn't let you upload full sized programs.

# ¿ May 21, 2013 00:22

Kire: Aug 25, 2006

JediTalentAgent posted:

I sort of figure that if/when I ever accidentally get thrown back in time I'll need that sort of edge to survive in a time just after the PS1, but right before the PS3...

I totally get what you're saying, though. I ended up going with that TI MSP430 based on price, but I couldn't figure out how to order it through TI so I ended up going with a reseller they listed. It seemed like the store and the purchase agreement on the TI site made it look like I wasn't actually qualified to buy it because I couldn't seem to find the right selection to put down for the step where it asks about your company/agency and the type of work it does, as well as their terms of sale that came up. I get the feeling that with what shipping was going to cost me, I likely should have just ordered a pair because I know that coming into it out of the cold, I WILL probably break the first one. I also just bought a small electronics kit to work on the meantime to reteach myself soldering over the next several days, hopefully.

Possible final question: Are any of the books on how to develop on the MSP430 that are more or less better than others for something more or less coming in from the cold. I know there are likely good/better online references, but I'm sort of still more attached to print-based material for a lot of things.

TI puts hilarious restrictions on everything and makes you jump through silly hoops to get anything from them.

I like the mental image of TI goons in MIB suits grilling everyone who wants to get an MSP430Gxxxx chip, while next door Massimo Banzi is handing out Arduino Megas and other high-end Atmel chips to anyone who walks by. Yes, TI, if the Iranians or Chinese get their hands on an 8-bit shift register, we'll be speaking Farsi by this time next week... :rolleyes:

I actually got told by them via email that I had been placed on the "US Denied Exports List", it turns out I had used my initial instead of my full last name while filling out their silly forms. I expected the FBI to crash through my windows the way they wrote that email (I was trying to get some 7805 voltage regulators!).

# ¿ May 25, 2013 14:52

Kire: Aug 25, 2006

Captain Capacitor posted:

So I picked up a Beaglebone Black. So far I haven't even figured out how to update it, but if this little board can save me $400 on a USB sniffer I'm so goddamn happy.

They're fun devices!

I wish my Beaglebone hadn't decided to stop talking with my winXP machine's serial port. No matter how many times I uninstall and reinstall the drivers, my computer has stopped recognizing it. :-(

# ¿ May 29, 2013 03:01

Kire: Aug 25, 2006

Martytoof posted:

Hey Dragon users. Mine finally arrived and it is basically pretty awesome. Do you guys use the board itself to power your target or do you typically run external power to your target and just rely on the dragon to run ISP/debugWire? I read that the voltage regulators on the Dragon are fragile as a teenager's self esteem, and people are recommending using them via a powered USB hub instead of a direct connection to a computer's USB port. Is this a real thing I should be worried about?

I have to throw mine in a case anyway, and I have a big-ish project box I'm planning on using, so I'm thinking about just killing two birds with one stone and making one projectbox that holds the AVR, and has a small standalone circuit that steps a separate wall wart down to 5v for powering my target.

Just wondering how you guys are handling your fragile baby dragons.

We've been using one in my lab and it's been getting man-handled by undergrads for a year and is still working, so, apparently we got lucky with a slightly more durable one.

# ¿ Jun 15, 2013 00:47

Kire: Aug 25, 2006

Has anybody ever used gdb for debugging a target from a host machine? I'm just curious, I learned about it in a class and it sounds complicated since gdb's command line interface gets very difficult to use very quickly, since terminals cannot display as much info as a GUI. So cross-debugging on a target seems really confusing, but kind of neat.

# ¿ Jun 18, 2013 03:37

Adbot: ADBOT LOVES YOU

# ¿ Apr 27, 2024 17:15

Kire: Aug 25, 2006

hendersa posted:

I've quite enjoyed my BBB. I have been very happy with the projects that I've managed to do with it over the three months that I've had it. The 3.8.x kernel has started to become far more stable, which is probably the only kernel branch that BBB users are interested in right now (it is where most of the BBB's features are being enabled). USB has come a long way in just the last month or so, HDMI audio/video stabilized about six weeks ago, Android support is catching up slowly, and documentation is continuing to spread via wikis and mailing lists.

Now, that being said, most of the BBB community has a superficial view on the platform. Helpful souls will gladly provide suggestions when you have problems, but those solutions are being cooked up by a much smaller part of the community. The others, while avid users, just parrot many solutions back to people on the mailing lists and whatnot. I've had to solve many of my own problems by digging into the kernel and looking things up for myself, but at least I try to share what I've found with others to hopefully avoid having someone else do the investigation over again because he/she couldn't find the answer to the same questions.

With the BBB, I've entered what I like to call the "dumb looks" phase of experience. When I ask questions, I just get dumb looks. I'm no expert, but I'm in that no-man's land where what I'm doing is just above the waterline of where most of the knowledge exists. That means that I'm down to picking apart the kernel code and digging through TI's 4000 page documents. It can be rewarding, but it can also be pretty tiring. But, it is also the point where neat, non-trivial projects begin to take shape.

It's a good little platform. Give it a try.

I second the "dumb looks" thing. I asked for help with an issue with my beaglebone A6 on a forum, and I made sure to point out that it WASN'T the loving beaglebone black, it was the regular one, and I got people telling me to reflash the eMMC and so forth (which only exists on the BBB). So loving irritating.

# ¿ Jun 20, 2013 03:23

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > 64K is still quite a lot! Embedded Programming Microthread