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by hendrixjl
Fri Mar 08, 2013 3:55 am
Forum: Bare metal, Assembly language
Topic: Linking Problem, Part 2
Replies: 4
Views: 1010

Re: Linking Problem, Part 2

Doh! I knew that!
Thanks a bunch!
by hendrixjl
Thu Mar 07, 2013 11:33 pm
Forum: Bare metal, Assembly language
Topic: Linking Problem, Part 2
Replies: 4
Views: 1010

Re: Linking Problem, Part 2

Frustration.
I tried each option. If the link succeeded, _start, et. al. wasn't there.
If the link failed, it said, "can't find c_irq_handler"

Thanks for the help.
by hendrixjl
Thu Mar 07, 2013 3:59 pm
Forum: Bare metal, Assembly language
Topic: Linking Problem, Part 2
Replies: 4
Views: 1010

Linking Problem, Part 2

jnc100 helped me get my bare metal code at https://github.com/hendrixjl/rPi/blob/master/Makefile linking, but now... I need _start (in .text.boot section) to appear at address 08000, but it is not showing up *anywhere* now when I build. It is at the top of libbare_metal.a, and the linker script has ...
by hendrixjl
Mon Mar 04, 2013 12:28 am
Forum: Bare metal, Assembly language
Topic: Linking Problem
Replies: 7
Views: 1186

Re: Linking Problem

Thanks a bunch!
I see you also fixed my divide issue by including libgcc.
That helps a lot.
John
by hendrixjl
Fri Mar 01, 2013 11:11 pm
Forum: Bare metal, Assembly language
Topic: Linking Problem
Replies: 7
Views: 1186

Re: Linking Problem

That was from the "desperately trying anything" department. Sometimes, I've noticed that libraries that come early in the link list can't get all of their undefined symbols from later in the link list. I've never understood it, mind you.

But that doesn't apply in this situation.
by hendrixjl
Fri Mar 01, 2013 10:07 pm
Forum: Bare metal, Assembly language
Topic: Linking Problem
Replies: 7
Views: 1186

Re: Linking Problem

For what it is worth: $ arm-none-eabi-nm bare_metal/libbare_metal.a kmain.o: U init_bars 00000000 T kmain U _Z16maneuver_programv stdout.o: U uart_put U uart_putc U uart_puts 00000000 T _Z5writec 00000034 T _Z5writePKc 00000060 T _Z5writePKvj timeUtils.o: U busyloop 00000000 T udelay bootstrap.o: 00...
by hendrixjl
Fri Mar 01, 2013 10:06 pm
Forum: Bare metal, Assembly language
Topic: Linking Problem
Replies: 7
Views: 1186

Re: Linking Problem

I gave it a try (declaring the whole function within extern "C"). Same problem.
I'm pretty sure that the pattern I used works to force the C++ compiler to not mangle the function name when it is actually defined. Which is to say, I think mine and your definition syntax do the same thing.
by hendrixjl
Fri Mar 01, 2013 5:40 pm
Forum: Bare metal, Assembly language
Topic: Linking Problem
Replies: 7
Views: 1186

Linking Problem

I've been working a project at https://github.com/hendrixjl/rPi to do some simple stuff with my Pi and a Rock Crawler (TM). I've reached a point where I can compile it for the Pi's linux using: make CC=gcc CPP=g++ AS=g++ LD=g++ and run it just fine. It is meant to compile and run bare metal using: m...
by hendrixjl
Mon Feb 18, 2013 8:06 pm
Forum: Automation, sensing and robotics
Topic: Lightweight 2-DOF turntable?
Replies: 2
Views: 991

Lightweight 2-DOF turntable?

Does someone make a lightweight "turntable-like" thing that you could mount a camera (or other sensor) on and programmatically swivel it around clockwise-counterclockwise in two dimensions?
by hendrixjl
Thu Feb 14, 2013 6:45 pm
Forum: Automation, sensing and robotics
Topic: Help with setting up PIR sensors
Replies: 37
Views: 5851

Re: Help with setting up PIR sensors

Just curious techpaul: what did you use to draw those diagrams?
Thanks,
by hendrixjl
Wed Feb 13, 2013 12:11 am
Forum: C/C++
Topic: Setting alternate function for GPIO pins
Replies: 7
Views: 4263

Re: Setting alternate function for GPIO pins

No, I never got it working.
by hendrixjl
Sat Feb 09, 2013 9:51 pm
Forum: Automation, sensing and robotics
Topic: Battery Power and USB WiFi?
Replies: 26
Views: 3812

Re: Battery Power and USB WiFi?

Thanks for all of the replies and all of the information.

I have another goal of keeping weight down. I guess I need to regroup on this one.

Let me ask, Does anyone think 6 AAs in series would be able to run the Pi + WiFi?

I'm also interested in a lower-power digital rf link for tty.
by hendrixjl
Sat Feb 09, 2013 9:30 pm
Forum: Automation, sensing and robotics
Topic: Battery Power and USB WiFi?
Replies: 26
Views: 3812

Re: Battery Power and USB WiFi?

Thanks for the info. I didn't know anything about the resistor "in front". What does "in front" mean?
by hendrixjl
Sat Feb 09, 2013 8:35 pm
Forum: Automation, sensing and robotics
Topic: Battery Power and USB WiFi?
Replies: 26
Views: 3812

Re: Battery Power and USB WiFi?

Yea, it was 7805A. You were right, of course; I'm not getting 5. My voltmeter is wobbly (analog), but I seem to be around 3.5v. The 7805 is pretty warm.... could I get better voltage if I put two 7805's in parallel so that that they have to support less amperage? As you might have guessed, I'm not e...
by hendrixjl
Sat Feb 09, 2013 7:43 pm
Forum: Automation, sensing and robotics
Topic: Battery Power and USB WiFi?
Replies: 26
Views: 3812

Battery Power and USB WiFi?

I can get my raspberry pi to come up under battery power - for instance, I'm currently using a 6volt "lantern" battery (the big one). One thing I can't get to work is the USB WiFi under battery power. I'm running the 6 volts through a 7508A 5-volt voltage regulator (which should support up to 1Amp)....
by hendrixjl
Fri Feb 08, 2013 1:20 am
Forum: Beginners
Topic: Hard drive *not* saving changes
Replies: 7
Views: 4751

Re: Hard drive *not* saving changes

It started acting up again. I first noticed files in /usr/include/boost with ".dpkg.new" at the end, instead of what was supposed to be there.
I'm setting up a new SD Card for my Pi.
by hendrixjl
Thu Feb 07, 2013 11:51 pm
Forum: Beginners
Topic: Hard drive *not* saving changes
Replies: 7
Views: 4751

Re: Hard drive *not* saving changes

I made the changes again tonight (they were "forgotten" from last night). This time I typed "sync" for good measure. I've rebooted a couple of times and the changes seem to be sticking now.
Oh well.
I'm suspicious of my SD card. Think I'll set up a backup.
John
by hendrixjl
Thu Feb 07, 2013 9:39 pm
Forum: Beginners
Topic: Hard drive *not* saving changes
Replies: 7
Views: 4751

Re: Hard drive *not* saving changes

I used sudo reboot last night. That should not require a sync by me.
I'll play with it some more when I get home from work.
by hendrixjl
Thu Feb 07, 2013 12:25 am
Forum: Beginners
Topic: Hard drive *not* saving changes
Replies: 7
Views: 4751

Hard drive *not* saving changes

Yesterday I posted a problem with apt-get, today..... Between reboots, my raspberry pi (linux) disk goes back to original state. I've been happily using my Pi for a while. Yesterday, apparently, I entered the twilight zone. I install boost program options. When I turn it off and back on, they are no...
by hendrixjl
Wed Feb 06, 2013 1:02 am
Forum: Beginners
Topic: Problem updating wheezy
Replies: 1
Views: 413

Problem updating wheezy

Any ideas? Is it safe to just delete /var/lib/dpkg/status and try again? $ sudo apt-get update Hit http://mirrordirector.raspbian.org wheezy InRelease Hit http://archive.raspberrypi.org wheezy InRelease Hit http://mirrordirector.raspbian.org wheezy/main armhf Packages Hit http://archive.raspberrypi....
by hendrixjl
Sun Feb 03, 2013 1:29 pm
Forum: C/C++
Topic: Setting alternate function for GPIO pins
Replies: 7
Views: 4263

Re: Setting alternate function for GPIO pins

Thanks for the replies, but I'm asking about bus 0 on connector P5 (rev 2 board) pins 2 and 3. I wanted to open up another i2c bus.
by hendrixjl
Sun Feb 03, 2013 2:58 am
Forum: C/C++
Topic: Setting alternate function for GPIO pins
Replies: 7
Views: 4263

Re: Setting alternate function for GPIO pins

To be more clear.... I would like to be able to use the i2c libraries under linux. For instance, I would like to do
i2cdetect -y 0
and detect it.
by hendrixjl
Sun Feb 03, 2013 2:26 am
Forum: C/C++
Topic: Setting alternate function for GPIO pins
Replies: 7
Views: 4263

Setting alternate function for GPIO pins

I understand that GPIO 28 and 29 (on P5) have ALT0 configuration of i2c sda0 and scl0 (rev 2 boards). How - under the raspbian linux with the GPIO configuration - can I select the ALT0 function for these two pins?
by hendrixjl
Sun Feb 03, 2013 2:11 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: GPIO 28,29,30,31 functions
Replies: 4
Views: 1801

GPIO 28,29,30,31 functions

I'm desperately looking for a description of the primary and alternate functions for gpio 28, 29, 30 and 31 which are on the rev 2 board P5 connector. Can someone help? Is this the right forum?
Thanks,
John
by hendrixjl
Fri Feb 01, 2013 5:09 pm
Forum: Automation, sensing and robotics
Topic: PiCrawler
Replies: 0
Views: 456

PiCrawler

I bought a Rock Crawler like this one ( http://www.toysrus.com/product/index.jsp?productId=11892055&CAWELAID=1064647239&pla=plat&cagpspn=pla ) at Dirt Cheap and thought, "I could attach a Pi to that!" So, I've started a project that may lead no where. I've started blogging it, and thought y'all migh...

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