Go to advanced search

by Daverj
Sun Sep 23, 2012 6:57 pm
Forum: General discussion
Topic: Blueberry Pi?
Replies: 3
Views: 4615

Re: Blueberry Pi?

Pretty much all of the requested extras people want, except the extra RAM, can be done with simple piggy-back boards. And are more appropriate that way since they aren't things that really are needed for the Foundation's intended purpose. So maybe talk to a circuit designer about creating a Blueberr...
by Daverj
Tue Aug 07, 2012 8:52 pm
Forum: General programming discussion
Topic: Why not program on x86 desktop?
Replies: 60
Views: 12521

Re: Why not program on x86 desktop?

I think a lot of people here are confusing the goal of the Foundation and it's original intended audience for the Pi with who it is that has actually purchased all of them. While it is the goal of the Foundation to put the Pi in the hands of kids to encourage a new generation of talented programmers...
by Daverj
Tue Aug 07, 2012 8:01 pm
Forum: C/C++
Topic: GPU Processing API
Replies: 124
Views: 45244

Re: GPU Processing API

I think the solution is fairly simple. Raise the price of the Pi by $2. This would raise an additional $2-$3 million dollars per year. That money could be given to Broadcom to hire a small team of 10-15 programmers at $100k-$150k/year each, plus leave several hundred thousand dollars for administrat...
by Daverj
Mon Aug 06, 2012 10:00 pm
Forum: Python
Topic: Email notifier/ CPU usage LEDs
Replies: 5
Views: 1535

Re: Email notifier/ CPU usage LEDs

Hey guys, How would I go about programming an LED to flash when a new email arrives? Or have 3 status LEDs that would each turn on depending on CPU usage? No idea how to get a program to search for things 'internally'! :) :) :) Thanks I don't have a specific "how to do it" answer, but general infor...
by Daverj
Sun Aug 05, 2012 10:23 pm
Forum: Python
Topic: RPi.gpio v0.3.1a and Raspbian
Replies: 21
Views: 15700

Re: RPi.gpio v0.3.1a and Raspbian

I've installed GPIO and all that, but every time I run a program the error message IOError: [Errno13] Permissiuon denied: '/sys/class/gpio/export' I've built this lovely buffered input/output card but I have yet to get a single line working. Jochen If you get that error message then you are using a...
by Daverj
Sun Aug 05, 2012 9:49 pm
Forum: C/C++
Topic: keyboard input linux/input.h
Replies: 7
Views: 6188

Re: keyboard input linux/input.h

Thank you Daverj. Is there any documentation of the remapping process available online? I haven't seen it. I assume it's buried in the kernel config files for keyboards. When you first run the Pi, or run raspi-config, and choose to configure the keyboard the first step is to select the type of keyb...
by Daverj
Sun Aug 05, 2012 1:01 am
Forum: C/C++
Topic: keyboard input linux/input.h
Replies: 7
Views: 6188

Re: keyboard input linux/input.h

My understanding is that EV_MSC / MSC_SCAN is used for remapping keys. So a wild guess is that the value represents a physical key on the input device (keyboard, etc...) and could be used to recognize that specific physical button as being pressed. Where as the EV_KEY / KEY_xxx is the way the system...
by Daverj
Sat Aug 04, 2012 10:45 pm
Forum: Beginners
Topic: downloading Win32DiskImager
Replies: 19
Views: 9456

Re: downloading Win32DiskImager

All of which makes a good case for encouraging people to do the Pi imaging with 'dd', like normal people do - instead of getting them involved in yet more Windows spamware. Yeah, yeah, I hear what you're saying. Using 'dd' requires them to learn Linux - and why should they be bothered with a one-of...
by Daverj
Sat Aug 04, 2012 7:00 pm
Forum: General programming discussion
Topic: Pi HDMI to MY PC 15 Pin plug ??
Replies: 4
Views: 2000

Re: Pi HDMI to MY PC 15 Pin plug ??

That is correct. Typically TVs and monitors have a yellow RCA jack for their composite video in (red and white jacks are usually for audio left and right in). RCA cables intended for video signals also typically have yellow RCA plugs on both ends. You often got one supplied with a VCR or older camco...
by Daverj
Sat Aug 04, 2012 6:53 pm
Forum: Beginners
Topic: downloading Win32DiskImager
Replies: 19
Views: 9456

Re: downloading Win32DiskImager

On many sites where you download free software there are a number of "download" buttons on the screen. But all except one of them are advertisers or spammers. You need to be very careful which one you click. It's like a minefield. Often the larger ones are the advertisers. Wave your mouse over each ...
by Daverj
Fri Aug 03, 2012 5:59 pm
Forum: General discussion
Topic: No crumb trail
Replies: 21
Views: 6658

Breadcrumbs

It would be very useful for navigation around the forum if there were "breadcrumbs" at the top and bottom of every page. They typically take the form of: Forum Name > Section > Subforum > (additional subforum) For example when viewing this post you might see: Raspi Forum > Raspberry Pi Foundation > ...
by Daverj
Fri Jul 27, 2012 7:52 pm
Forum: Python
Topic: Could someone run through this code with me?
Replies: 23
Views: 2849

Re: Could someone run through this code with me?

So you know that [0], what's that for? As well as the [1]. As he mentioned above, the [0] and [1] reference the first and second elements of the two numbers. Think of the size = [400,400] as initializing 2 elements of an array. And the size[0] as referencing the first element of the array, while si...
by Daverj
Thu Jul 26, 2012 4:54 pm
Forum: Troubleshooting
Topic: Possible to detect analog audio jack insertion?
Replies: 6
Views: 2960

Re: Possible to detect analog audio jack insertion?

The way most devices detect a plug insertion on a 3.5mm jack is they use a special jack that has an isolated switch built into the jack. That switch connects to a port, like a GPIO pin. So simply reading that port tells you if something is plugged in. That type of jack is readily available, but has ...
by Daverj
Thu Jul 26, 2012 4:38 pm
Forum: C/C++
Topic: GPIO Programming and Interrupts
Replies: 64
Views: 31637

Re: GPIO Programming and Interrupts

but If I run my single program without linux on the bare metal as a kernal isn't there only one priority - mine!? Yes, but depending on what the slowest time it takes to get once around your loop, some of your hardware might not be sensed and controlled fast enough to keep it functioning. Even in a...
by Daverj
Wed Jul 25, 2012 11:25 pm
Forum: C/C++
Topic: GPIO Programming and Interrupts
Replies: 64
Views: 31637

Re: GPIO Programming and Interrupts

I've been writing C for about 30 years, and ISRs for a few years before that, but I have very little experience with Linux. And especially with Linux running on something small like the ARM. So I'm mostly looking for what's possible vs what's practical, and figure out the limits of what I can get th...
by Daverj
Wed Jul 25, 2012 10:32 pm
Forum: C/C++
Topic: GPIO Programming and Interrupts
Replies: 64
Views: 31637

Re: GPIO Programming and Interrupts

not requiring the program to stop and wait for an interrupt. That would be either a contradiction in terms or how every computer handles interrupts. Well of course physically the program does stop while the ISR is executed. What I meant was not adding some call in the program that makes the program...
by Daverj
Wed Jul 25, 2012 8:49 pm
Forum: C/C++
Topic: GPIO Programming and Interrupts
Replies: 64
Views: 31637

Re: GPIO Programming and Interrupts

I am also interested in using GPIO and interrupts. But my application would require true asynchronous interrupt handlers, and not requiring the program to stop and wait for an interrupt. I'd like to interface an optical rotary encoder to 3 of the GPIO pins (A, B, and Index). Then have three very sma...
by Daverj
Wed Jul 25, 2012 7:48 pm
Forum: General programming discussion
Topic: Directfb/Pi
Replies: 26
Views: 14772

Re: Directfb/Pi

I've gotten directfb (1.6.0) to compile and compiled GTK with the directfb backend enabled. When I try launching the gtk-demo I get a black screen with a mouse pointer before it locks up. The black screen and mouse pointer never go away and I have to ssh in and reboot. Does anyone have a suggestion...
by Daverj
Wed Jul 25, 2012 7:42 pm
Forum: General programming discussion
Topic: Options for development environment
Replies: 12
Views: 15096

Re: Options for development environment

Sorry if this is a dumb question, but I've heard of Eclipse but never used it. Does this mean that I can install Eclipse on WinXP, install your compilers wherever Eclipse expects them, install "the make tool" (where do I get that?), and then I'd be able to run this from WinXP to do my development wi...
by Daverj
Mon Jul 23, 2012 7:06 pm
Forum: Python
Topic: cycling between JPEGs
Replies: 8
Views: 8272

Re: cycling between JPEGs

SUCCESS!! I created a set of 10 surfaces and blited the 10 images into them. Then in my main loop I blited the surfaces to the display. I'm now getting about 12.5 images per second (0.08 sec per image) Your comment earlier about RAM does make me wonder what will happen when I go with the full sized ...
by Daverj
Mon Jul 23, 2012 5:53 pm
Forum: Python
Topic: cycling between JPEGs
Replies: 8
Views: 8272

Re: cycling between JPEGs

I tried it with 2 images. Same speed. I tried moving the images from the USB stick to the Pi home folder on the SD card. Same speed. And the SD card is a class 10 Sandisk Ultra, so I doubt that's slowing anything down. I tried adding pygame.HWSURFACE to the set_mode command and that speeds it up sli...
by Daverj
Mon Jul 23, 2012 5:30 am
Forum: Python
Topic: cycling between JPEGs
Replies: 8
Views: 8272

Re: cycling between JPEGs

As far as I know there's no scaling going on. My test images are 1500x1000 and the screen mode is 1920x1080. I see black at the bottom and a larger black on the right of the images, so they don't fill the screen. The final images will be larger and fill the screen. I did try running the program dire...
by Daverj
Mon Jul 23, 2012 1:18 am
Forum: Python
Topic: cycling between JPEGs
Replies: 8
Views: 8272

Re: cycling between JPEGs

Thanks for that. I tried out pygame, but I don't think that's going to be fast enough. I tried the example above but using 10 JPEG images. I removed the background fills and the clock delays and just used 10 blits followed by display.flips, since the images are all the same size (current test was wi...
by Daverj
Sat Jul 21, 2012 5:46 am
Forum: Python
Topic: cycling between JPEGs
Replies: 8
Views: 8272

cycling between JPEGs

Is there a simple method of throwing up JPEG images full screen using Python? Preferably a method that can change the images very fast. I'd like to do a simple script that can cycle through maybe 10 images per second as a GPIO pin is held down and then stop on one of them when the pin is released. I...
by Daverj
Fri Jul 20, 2012 5:04 pm
Forum: General programming discussion
Topic: Options for development environment
Replies: 12
Views: 15096

Re: Options for development environment

Thanks for the suggestions. I did use Cygwin briefly about a decade ago, when trying to get ECOS running on a Cirrus ARM chip.

Go to advanced search