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by jwatte
Thu Apr 20, 2017 7:11 am
Forum: Troubleshooting
Topic: Is Sys() mode broken in wiringPi?
Replies: 4
Views: 688

Is Sys() mode broken in wiringPi?

Using the latest Raspbian on a Raspberry Pi 2+, programming in C++. I've been trying to read a couple of GPIO pins for hours now, and it just won't do right. The pins were identified by number on the Adafruit Kippah (the adapter for the 40-pin parallel dotclock displays.) First, I didn't know whethe...
by jwatte
Sat Jun 25, 2016 1:17 am
Forum: Graphics, sound and multimedia
Topic: Pi-based CarPC using iPhone for control?
Replies: 8
Views: 2482

Re: Pi-based CarPC using iPhone for control?

Yes, the RPi3 will not need a USB WiFi dongle.
by jwatte
Sat May 14, 2016 9:16 pm
Forum: Device Tree
Topic: Building HAT: ID_I2C doesn't show up
Replies: 7
Views: 1760

Re: Building HAT: ID_I2C doesn't show up

Thanks; I do see it in the /proc/device-tree/hat directory!
raspi-gpio also sees the pins correctly configured.

Now for figuring out how to build a proper device tree overlay blob ...
by jwatte
Sat May 14, 2016 7:29 pm
Forum: Device Tree
Topic: Building HAT: ID_I2C doesn't show up
Replies: 7
Views: 1760

Re: Building HAT: ID_I2C doesn't show up

Next question: How do I verify that the EEPROM was correctly applied during boot? I have built an image and successfully written it and successfully rebooted, but there's no mention of GPIOs being configured in dmesg, and the /sys/class/gpio tree knows nothing about it. Here's by board.txt: ########...
by jwatte
Mon May 09, 2016 4:20 pm
Forum: Advanced users
Topic: Kernel soft PWM module?
Replies: 3
Views: 832

Re: Kernel soft PWM module?

What's the general theory of operation behind that library? What makes it better than a high-priority thread?
by jwatte
Mon May 09, 2016 4:17 pm
Forum: Device Tree
Topic: Building HAT: ID_I2C doesn't show up
Replies: 7
Views: 1760

Re: Building HAT: ID_I2C doesn't show up

Thanks for the answer!

You probably want to add this to the "hats" github repo somewhere, because that's the obvious instructions I'm following...
by jwatte
Mon May 09, 2016 5:52 am
Forum: Advanced users
Topic: Kernel soft PWM module?
Replies: 3
Views: 832

Kernel soft PWM module?

I've tried using the soft PWM functions in the wiringPi library, but they seem to just use a real-time thread and toggle the GPIO pin from userspace, albeit with memory mapped I/O, so the toggling itself is fast. (The thread in turn seems to use polling for hand-off when starting, so start time is o...
by jwatte
Mon May 09, 2016 4:57 am
Forum: Device Tree
Topic: Building HAT: ID_I2C doesn't show up
Replies: 7
Views: 1760

Building HAT: ID_I2C doesn't show up

I'm using an original Pi B+. I have made a HAT prototype, that hooks up the recommended OnSemi 24C32 EEPROM with 3.3V pull-ups to the ID_I2C pins. I've built a eeprom.txt file that describes the functions of the pins, and compiled the EEP file. Now, I want to flash the EEPROM (I use a jumper to pull...
by jwatte
Sun May 08, 2016 9:40 pm
Forum: General discussion
Topic: Using an I2C clock (DS1307, DS3231) on latest raspbian
Replies: 13
Views: 6769

Using an I2C clock (DS1307, DS3231) on latest raspbian

There are many tutorials for how to turn on a hardware I2C RTC clock for the Raspberry Pi, so it remembers the time even if it's not connected to a network (and also so that log timestamps from booting are more correct than the late arrivals of network time.) All of them are bad or wrong in some way...
by jwatte
Tue Apr 05, 2016 5:40 pm
Forum: Advanced users
Topic: Timecode in the h264 encoder?
Replies: 10
Views: 2482

Re: Timecode in the h264 encoder?

That's good information, too! This has been discussed previously on the Camera subforum I find that when I try to search the forum, I get a whole lot of talk about how to use motion/raspicam/whatever built-in tools, and very little about the underlying code and API to access it. In the best of world...
by jwatte
Tue Apr 05, 2016 4:52 pm
Forum: Advanced users
Topic: Timecode in the h264 encoder?
Replies: 10
Views: 2482

Re: Timecode in the h264 encoder?

Meanwhile, I've spelunked a little more, and the libavformat library comes with a sample program that reads a H.264 file in and writes a MP4 file out. That program can be hacked-at and bashed into the RaspiVid-mini I'm using until it uses that library to create and write the file, rather than just f...
by jwatte
Mon Apr 04, 2016 6:42 pm
Forum: Camera board
Topic: Sample code for real-time libav usage from raspivid?
Replies: 0
Views: 317

Sample code for real-time libav usage from raspivid?

I'd like to take the H.264 codec stream from the hardware encoder, and write it directly to MP4 (rather than raw H.264). Presumably I need to use the libavformat library, and functions like avformat_write_header() and such. To get that going, I need to descend a tree of codec and muxer configuration...
by jwatte
Mon Apr 04, 2016 6:23 pm
Forum: Advanced users
Topic: Timecode in the h264 encoder?
Replies: 10
Views: 2482

Re: Timecode in the h264 encoder?

Thanks for the pointers!

I'll go spelunking and see if it's possible to write the timecode/format while writing the raw stream, or whether I need to do this offline after the fact.
by jwatte
Mon Apr 04, 2016 2:00 am
Forum: Advanced users
Topic: Timecode in the h264 encoder?
Replies: 10
Views: 2482

Timecode in the h264 encoder?

I'm recording on a Raspberry Pi 2 using a cut-down version of RaspiVid, and playing back on a Windows machine after transferring over the network (using scp when done -- not streaming.) When I play back a h264 file that I have created on Raspberry Pi (using a Pi2, with Jesse) on VLC on Windows (late...
by jwatte
Mon Apr 04, 2016 1:56 am
Forum: Advanced users
Topic: MMAL API -- did it change in the last year?
Replies: 4
Views: 912

Re: MMAL API -- did it change in the last year?

Okay, with a modern version of gdb, debugging was easier, and it turns out I was passing FALSE to MMAL_PARAMETER_CAPTURE which made it not capture. Fancy that!

Thanks for the pointers, I do appreciate it.
by jwatte
Sun Apr 03, 2016 4:35 am
Forum: Advanced users
Topic: How can I get debug info for locals?
Replies: 5
Views: 1059

Re: How can I get debug info for locals?

I blew away my sdcard and installed the latest, lightweight, raspian from a couple of weeks ago.
I now get gcc 4.9.2, and gdb 7.7.1, and I can read the value of local variables when compiling with -g and -O0. Yay!
Thanks for the help.
by jwatte
Sat Apr 02, 2016 6:00 pm
Forum: Advanced users
Topic: How can I get debug info for locals?
Replies: 5
Views: 1059

Re: How can I get debug info for locals?

Interesting.
I thought I did a full system upgrade already, (using dist-upgrade) but it does look like an older version.
Surprising that GCC got upgraded, but GDB did not.

Oh -- I had not updated sources.lst to point at jessie before doing dist-upgrade. I'll try with 7.7 and hope for the best!
by jwatte
Fri Apr 01, 2016 9:30 pm
Forum: Advanced users
Topic: How can I get debug info for locals?
Replies: 5
Views: 1059

Re: How can I get debug info for locals?

Yes, it should, but that doesn't change the actual problem I want help with at all!
by jwatte
Fri Apr 01, 2016 5:02 pm
Forum: Advanced users
Topic: MMAL API -- did it change in the last year?
Replies: 4
Views: 912

Re: MMAL API -- did it change in the last year?

Raspivid built from the userland on github yesterday, works, as in it encodes H264 that VLC can play back. However, it does NOT show the preview on the display, at least with -f (fullscreen) option which is the only one I tested. Is this a side effect of me now using the official PiTFT display and f...
by jwatte
Fri Apr 01, 2016 5:51 am
Forum: Advanced users
Topic: How can I get debug info for locals?
Replies: 5
Views: 1059

How can I get debug info for locals?

I'm trying to debug a program, but gdb stubbornly refuses to print my local variable values. I compile with -O0 and -gdawrf-4. When I do "info local" it prints some global variables, but not the locals of the function. I then tried to debug a very simple program, and that fares even worse -- GDB doe...
by jwatte
Fri Apr 01, 2016 5:18 am
Forum: Advanced users
Topic: MMAL API -- did it change in the last year?
Replies: 4
Views: 912

Re: MMAL API -- did it change in the last year?

For example, I notice that a bunch of libraries that were there in 2015 aren't there now (they seem to be plugins, that perhaps moved to the /opt/vc/lib/plugins directory?) What changes should I make to my source to make it work again? Also, the source does not build with the NEW userland -- vc_genc...
by jwatte
Fri Apr 01, 2016 5:11 am
Forum: Advanced users
Topic: MMAL API -- did it change in the last year?
Replies: 4
Views: 912

MMAL API -- did it change in the last year?

I have a program that worked fine last year in March, using MMAL to do image analysis on the "preview port" data (not actually on the display) and doing H.264 encoding on the main port to write to a file. However, I recently did a full apt-get upgrade of everything, and that same code (with small mo...
by jwatte
Thu Mar 24, 2016 4:05 am
Forum: Advanced users
Topic: ext2+nilfs2 on sd-card
Replies: 7
Views: 2762

Re: ext2+nilfs2 on sd-card

FWIW: I'm a fan of nilfs2. I lost a full disk a few years back to this FS, which was a bummer, but the developer has found and fixed that bug, and I've been meaning to set one up again. I now have the perfect case! My RPi controls a robot, which logs telemetry to files in /var/tmp, as well as record...
by jwatte
Mon Feb 22, 2016 6:38 am
Forum: Official Foundation Display
Topic: disable screensaver
Replies: 10
Views: 7223

Re: disable screensaver

"Jessie now provides a user autostart at "~/,config/lxsession/LXDE-pi/autostart", which takes precedence over the global autostart." That's what I read in documentation, too, but I couldn't get it to work. Editing the global file did work. (This also let me remove pcmanfm and lxpanel) BTW, when usin...
by jwatte
Sun Feb 21, 2016 7:09 am
Forum: Official Foundation Display
Topic: Non square pixels?
Replies: 20
Views: 11651

Re: Non square pixels?

Yes, this is terrible. I also didn't discover it until after I purchased the display.

How can someone, in this day and age, even build a display like that? Like, who, in what factory, thought this was a good idea?

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