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by lilzz
Tue Nov 18, 2014 6:53 pm
Forum: C/C++
Topic: The following defines and linux codes
Replies: 3
Views: 863

Re: The following defines and linux codes

Not sure what the third define is - have you copied it correctly? But the other two simple define A to be (1) and B to be (2) - remember the preprocessor is a direct text substitution. The second question ,sysconf returns a long int, that's probably a 64 bit value but it depends on the build IRC. _...
by lilzz
Mon Nov 17, 2014 5:22 pm
Forum: General discussion
Topic: iwlist finding out Wifi adaptor's adhoc ability
Replies: 3
Views: 583

Re: iwlist finding out Wifi adaptor's adhoc ability

DougieLawson wrote:The edimax driver in Linux/Raspbian does NOT support ad-hoc.

You need a special driver to support running an edimax as an access point. AFAIK there is no ad-hoc driver available.
so if it supports it. iwlist AP should list its capability ?
by lilzz
Mon Nov 17, 2014 5:21 pm
Forum: C/C++
Topic: The following defines and linux codes
Replies: 3
Views: 863

The following defines and linux codes

#define A (1) #define B (2) #define C(32) what does that means? It's not a dimension of the array. PageSize = sysconf(_SC_PAGESIZE); PageMask = (~(PageSize-1)); addr_start = IO_BASE & PageMask; addr_offset = IO_BASE & ~PageMask; So the sysconf function finds out the system's page size. But what's a...
by lilzz
Mon Nov 17, 2014 4:23 pm
Forum: General discussion
Topic: iwlist finding out Wifi adaptor's adhoc ability
Replies: 3
Views: 583

iwlist finding out Wifi adaptor's adhoc ability

I have one the Edimax wifi adapter and on spec it says it support adhoc.

I did

Code: Select all

 iwlist AP
Nothing is shown. Can adhoc ability be shown programmatically?
by lilzz
Thu Nov 13, 2014 7:16 pm
Forum: C/C++
Topic: Does Pi use gpio driver?
Replies: 5
Views: 957

Re: Does Pi use gpio driver?

ShiftPlusOne wrote:As with the other thread, please provide context. Are you trying to get support for a pi-like knock-off sbc?
just for learning process as I look at other stuffs and I do comparison. I don't have any other system on hand besides the Pi.
by lilzz
Thu Nov 13, 2014 6:54 pm
Forum: C/C++
Topic: Does Pi use gpio driver?
Replies: 5
Views: 957

Re: Does Pi use gpio driver?

https://github.com/raspberrypi/linux/blob/rpi-3.12.y/arch/arm/mach-bcm2708/bcm2708_gpio.c thanks, if that bcm2708_gpio.c is not available, can I use the generic gpiolib instead under the drivers/gpio folder? this is a general question because I see a lot of chipsets outside of broad com do not prov...
by lilzz
Thu Nov 13, 2014 6:51 pm
Forum: General discussion
Topic: linux, how does this work ?
Replies: 6
Views: 940

linux, how does this work ?

I see a folder named boot/ contains gzrom.bin, initrd.pz, ramdisk.tar.gz, vmlinux /bootloader contains pmon.tgz, u-boot.tar.gz /kernel contains linux-2.6.21.5.tar.gz and linux-2.6.32-20140325.tar.gz /os contains minisys.tar.gz questions, 1) which one get boot first? in boot folder or boot loader fol...
by lilzz
Thu Nov 13, 2014 6:46 pm
Forum: C/C++
Topic: Does Pi use gpio driver?
Replies: 5
Views: 957

Does Pi use gpio driver?

https://github.com/raspberrypi/linux/tr ... ivers/gpio


I don't see any gpio specifically for the pi?
by lilzz
Mon Nov 10, 2014 2:03 am
Forum: C/C++
Topic: When the Pi use bcm2835.c?
Replies: 1
Views: 605

When the Pi use bcm2835.c?

I am looking at the Pi kernel and see this

https://github.com/raspberrypi/linux/tr ... /bcm2835.c

when does pi use that file? Not at at the booting stage because at booting it uses boot code.bin.
by lilzz
Wed Nov 05, 2014 8:42 pm
Forum: Python
Topic: matplotlib plot not showing up.
Replies: 2
Views: 4021

matplotlib plot not showing up.

import matplotlib # Force matplotlib to not use any Xwindows backend. matplotlib.use('Agg') from matplotlib import pyplot from matplotlib import dates fig = pyplot.figure() ax = fig.add_subplot(111) ax.xaxis.set_major_locator(dates.HourLocator(interval=6)) ax.xaxis.set_major_formatter(hfmt) pylab.x...
by lilzz
Wed Nov 05, 2014 4:19 pm
Forum: General discussion
Topic: /etc/watchdog.conf
Replies: 2
Views: 1018

/etc/watchdog.conf

max-load-1=24
reboot the device if the load goes over 24 over 1 minute. you would have needed 24 Raspberry Pi to complete that task in 1 minute

what does that means?
by lilzz
Wed Nov 05, 2014 8:35 am
Forum: General discussion
Topic: how to design a dead man switch for pi
Replies: 1
Views: 849

how to design a dead man switch for pi

if the pi is unresponsive then I like the circuit to pulse a reset signal to the pi.

the question, how should I check for the Pi is non responsive software wise?
And LM335 watchdog timer would be used to generate the reset pulse ?
by lilzz
Fri Oct 31, 2014 4:04 pm
Forum: General discussion
Topic: possible to design own version of pi?
Replies: 9
Views: 1216

Re: possible to design own version of pi?

RaTTuS wrote:http://www.raspberrypi.org/forums/viewforum.php?f=98
is going to be the best you can do.
unless you are ordering millions you will not get access to the SOC

is there a computer module that use the same SOC as the Pi?
by lilzz
Fri Oct 31, 2014 3:54 pm
Forum: General discussion
Topic: possible to design own version of pi?
Replies: 9
Views: 1216

Re: possible to design own version of pi?

if i use DDR3 memory instead of DDR2 or vice versa that means I need to program the memory registers. But I do not have source of boot code.bin to tweak those memory register timings so I guess its not possible then? The memory is PoP stacked on top of the SOC: http://en.wikipedia.org/wiki/Package_...
by lilzz
Fri Oct 31, 2014 3:39 pm
Forum: General discussion
Topic: possible to design own version of pi?
Replies: 9
Views: 1216

possible to design own version of pi?

if i use DDR3 memory instead of DDR2 or vice versa that means I need to program the memory registers. But I do not have source of boot code.bin to tweak those memory register timings so I guess its not possible then?
by lilzz
Thu Oct 30, 2014 9:45 pm
Forum: Troubleshooting
Topic: Howto disable GPU manually to converse power?
Replies: 8
Views: 2022

Re: Howto disable GPU manually to converse power?

No, I am not using a 78xx regulator I am using a 12VDC to 5VDC step down LM2576H-5V which is supposedly over 90% efficient, its switching regulator not a linear regulator and it gets hot.

I couldn't think of anything else besides getting the Pi consumes lower power.
by lilzz
Thu Oct 30, 2014 7:41 pm
Forum: Troubleshooting
Topic: Howto disable GPU manually to converse power?
Replies: 8
Views: 2022

Howto disable GPU manually to converse power?

I have Pi unit running remotely by SSH into it. I do not need GPU therefore I like Pi to disable to converse power.

I have a custom voltage generator generates 5V to supply the Pi but voltage regulator is awfully hot as now.

I like to disable GPU and hopefully regulator gets less hot.
by lilzz
Thu Oct 30, 2014 7:09 pm
Forum: General discussion
Topic: Why the boot code.bin and Start.elf aren't open sourced?
Replies: 7
Views: 1622

Re: Why the boot code.bin and Start.elf aren't open sourced?

Broadcom Intellectual Property Rights It's nothing more than init their chipset SOC, broadcom's business is selling chipsets. No point in hiding those code. They got no use outside of the specific chipset. In fact, most companies give away their chipset specific driver codes so to enable widespread...
by lilzz
Thu Oct 30, 2014 6:40 pm
Forum: General discussion
Topic: Why the boot code.bin and Start.elf aren't open sourced?
Replies: 7
Views: 1622

Why the boot code.bin and Start.elf aren't open sourced?

The whole Pi project is for learning. Why need to cover them up?
by lilzz
Wed Oct 29, 2014 4:10 pm
Forum: Bare metal, Assembly language
Topic: ARM versus MIPS GPIO.
Replies: 3
Views: 1680

Re: ARM versus MIP GPIO.

[email protected] wrote: ioremap is a Linux kernel call AIUI. mmap works from userland.

Is the MIPS code you're looking at running in the Kernel or a user program?

-Gordon
End goal is I want to use it in the user land.
So, is that means I can adopt the ARM code for the MIPS ?
by lilzz
Wed Oct 29, 2014 6:17 am
Forum: Bare metal, Assembly language
Topic: ARM versus MIPS GPIO.
Replies: 3
Views: 1680

ARM versus MIPS GPIO.

For Pi ARM GPIO is accessed through memory mapped gpio_map = (uint32_t *)mmap( (caddr_t)gpio_mem, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, mem_fd, GPIO_BASE); *(gpio_map+offset) =value where gpio_map is virtual address. different GPIO is accessed through different offset. For MIPS the...
by lilzz
Wed Oct 29, 2014 5:11 am
Forum: General discussion
Topic: Boot Sequence from Kernel Source
Replies: 1
Views: 441

Boot Sequence from Kernel Source

I like study the Pi boot up sequence from Kernel Source
Where I should get start

Bootup , and register initialization of SOC I like to find out more about that.

what's sequence of files I should study under the kernel source?
by lilzz
Tue Oct 28, 2014 4:43 pm
Forum: C/C++
Topic: what's this linux structure?
Replies: 4
Views: 879

what's this linux structure?

#define GPIO_CHIP(_bank) { \ .irq_base = IRQ_GPIO_BASE_ ## _bank, \ .gpio_chip = { \ .label = "Bank " # _bank, \ .owner = THIS_MODULE, \ .set = gpio_set_value, \ .get = gpio_get_value, \ .direction_output =gpio_direction_output, \ .direction_input = gpio_direction_input, \ .base = GPIO_BASE_ ## _ba...
by lilzz
Sun Oct 26, 2014 10:50 pm
Forum: Beginners
Topic: How to setup Pi first time without monitor?
Replies: 6
Views: 1118

Re: How to setup Pi first time without monitor?

Install a tool called Fing. That runs on windows, Mac, android, Linux (including Raspbian) and will scan your network and identify your RPi. Once you find your RPi you can SSH in to run raspi-config. This is assuming Pi getting IP address successfully all by itself without any assistance. What if t...
by lilzz
Sun Oct 26, 2014 10:46 pm
Forum: Beginners
Topic: How to setup Pi first time without monitor?
Replies: 6
Views: 1118

Re: How to setup Pi first time without monitor?

I put the OS into the SDCard and I do not have a monitor to hook to the Pi. How to run rasp-config on Pi without monitor? I don't know the IP address of Pi so I don't know how SSH into it. http://www.raspberrypi.org/documentation/remote-access/README.md You were given this link in your other thread...

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