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by RyuKajiya
Sun Feb 01, 2015 1:46 pm
Forum: Camera board
Topic: Find out exact moment when camera starts capturing
Replies: 22
Views: 2886

Re: Find out exact moment when camera starts capturing

I was not talking about four individual pictures, but the frames that are taken for one.
I read that post, and it also says they are added together, which is a kind of merge.
You can add, subtract, divide, multiply or delta frames together, which are all ways to merge frames/images.
by RyuKajiya
Sat Jan 31, 2015 10:02 pm
Forum: Camera board
Topic: Find out exact moment when camera starts capturing
Replies: 22
Views: 2886

Re: Find out exact moment when camera starts capturing

I was thinking wrong anyways. If it is always 4 frames, that means it is 6 * 4 = 24 seconds. Lets say the setup takes a bit, then sending the command to capture takes 1 second, that would produce the 25 second timers i get at subsequent captures. I have set the framerate to 4/6 and got these results...
by RyuKajiya
Sat Jan 31, 2015 5:43 pm
Forum: Camera board
Topic: Find out exact moment when camera starts capturing
Replies: 22
Views: 2886

Re: Find out exact moment when camera starts capturing

Take a look here: http://www.raspberrypi.org/documentation/raspbian/applications/camera.md --shutter, -ss Set shutter speed Set the shutter speed to the specified value (in microseconds). There is currently an upper limit of approximately 6000000us (6000ms, 6s) past which operation is undefined. I a...
by RyuKajiya
Sat Jan 31, 2015 5:20 pm
Forum: Camera board
Topic: Find out exact moment when camera starts capturing
Replies: 22
Views: 2886

Re: Find out exact moment when camera starts capturing

I was trying not to use raspistill, and was quite happy with the python library. And 6 seconds is the maximum shutter time for the pi camera. Whatever documentation you found there is not up to date. The 6 seconds have been established quite some time ago already. But that really is the maximum the ...
by RyuKajiya
Sat Jan 31, 2015 4:42 pm
Forum: Camera board
Topic: Find out exact moment when camera starts capturing
Replies: 22
Views: 2886

Re: Find out exact moment when camera starts capturing

Interesting. The first capture actually takes longer then subsequent ones. import picamera from time import sleep from fractions import Fraction import datetime with picamera.PiCamera() as camera: camera.resolution = (1280, 720) # Set a framerate of 1/6fps, then set shutter # speed to 6s and ISO to ...
by RyuKajiya
Sat Jan 31, 2015 4:24 pm
Forum: Camera board
Topic: Find out exact moment when camera starts capturing
Replies: 22
Views: 2886

Re: Find out exact moment when camera starts capturing

Since i set the framerate it should be calculate-able how long i would have to wait between the callback and starting to get the second frame? Shouldn't it just be 1s/framerate to get the length of one frame? Just came to my mind that in my case it would be enough to know beforehand how long it take...
by RyuKajiya
Sat Jan 31, 2015 3:57 pm
Forum: Camera board
Topic: Find out exact moment when camera starts capturing
Replies: 22
Views: 2886

Re: Find out exact moment when camera starts capturing

Well, the explanation of the code says that this results in a 6 seconds exposure time, i just want to know when this starts. So probably the first pixel being exposed. What i want to do with this is some light painting and partial lighting experiments. I want to control several LEDs that are only li...
by RyuKajiya
Sat Jan 31, 2015 3:28 pm
Forum: Camera board
Topic: Find out exact moment when camera starts capturing
Replies: 22
Views: 2886

Find out exact moment when camera starts capturing

I am playing around with the https://github.com/waveform80/picamera library to capture long exposure images. There is a good example on how to do this in the documentation of this library: import picamera from time import sleep from fractions import Fraction with picamera.PiCamera() as camera: camer...
by RyuKajiya
Mon Jan 19, 2015 9:48 am
Forum: Raspbian
Topic: Hardware SPI?
Replies: 3
Views: 571

Re: Hardware SPI?

Thanks.
I was not planning on using Occidentalis, but if the driver was missing i would have installed it manualy.
Is there an up to date overview of what current Raspbian distro contains?
by RyuKajiya
Mon Jan 19, 2015 7:17 am
Forum: Raspbian
Topic: Hardware SPI?
Replies: 3
Views: 571

Hardware SPI?

I have read in a few tutorials now that the normal Wheezy distribution does not contain hardware SPI drivers, and if you need it you should install Adafruits Occidentalis. I have been digging a bit and found some tutorials on how to install those drivers manualy, which results in the SPI devices sho...
by RyuKajiya
Wed Dec 31, 2014 9:44 am
Forum: Python
Topic: Strange display controling LED matrix
Replies: 3
Views: 771

Re: Strange display controling LED matrix

That is just an elegant way to set the bits for the row register. On the 0th row the first bit is set high, all other low, on the first row the second bit is set high, all other low, and so on. The print shows the rows of the input array i use, judging from this output everything looks fine too. May...
by RyuKajiya
Wed Dec 31, 2014 12:35 am
Forum: Python
Topic: Strange display controling LED matrix
Replies: 3
Views: 771

Strange display controling LED matrix

I am trying to write a simple control program for a 8x8 LED matrix. The rows and columns are connected to shift registers (cathode uses transistors). I checked the circuit, and it appears to be correct. I can manually trigger any LED in the matrix i like. But when i try to shift some bits into the r...
by RyuKajiya
Sun Dec 21, 2014 8:32 pm
Forum: Other projects
Topic: Control RGB LED Matrix
Replies: 2
Views: 1875

Re: Control RGB LED Matrix

Thanks for your suggestion. Will take a look at those shift registers. But a quick search already showed that they are not as easy to get as common 74HC595. It would reduce the needed components tho, because with 16bit registers i could change the setup to two 16x8 matrices. The RPi does not have to...
by RyuKajiya
Sun Dec 21, 2014 2:42 pm
Forum: Other projects
Topic: Control RGB LED Matrix
Replies: 2
Views: 1875

Control RGB LED Matrix

I am currently trying to figure out a good and easy way to control a RGB LED Matrix. I don't need any dimming at all, so PWM is not needed. Also i don't really need large color depth, either a color is on or off is enough. Maybe i can play around later to increase the color depth a bit, but that wou...
by RyuKajiya
Thu Nov 20, 2014 12:36 pm
Forum: Java
Topic: Write to framebuffer
Replies: 3
Views: 1388

Re: Write to framebuffer

I have pixel format, width and height information allready, so i can just create a BufferedImage, paint to it and write it to /dev/fb1 ?
What do i use to write to it then ? FileOutputStream ?
by RyuKajiya
Thu Nov 20, 2014 12:17 pm
Forum: Java
Topic: Write to framebuffer
Replies: 3
Views: 1388

Write to framebuffer

I am trying to find a way to display something with java on a tft display that is connected through the GPIO port. ( C-Berry touch ) I allready managed to install a kernel driver that creates a new framebuffer for this display, but still need a way to write to a framebuffer from java now. The displa...
by RyuKajiya
Wed Nov 19, 2014 7:08 am
Forum: Java
Topic: Desktop Eclipse integration with RPi?
Replies: 12
Views: 4162

Re: Desktop Eclipse integration with RPi?

If you set it up in NetBeans allready you can look at the code that is generated from NetBeans. It contains everything you need to set up ant remote deployment, you just have to copy it over to your Eclipse project, set it up to use ant and fill in the variables.
by RyuKajiya
Mon Nov 17, 2014 7:48 pm
Forum: Java
Topic: read temperature from DHT11, using pi4j
Replies: 5
Views: 10251

Re: read temperature from DHT11, using pi4j

I think the pi4j pin handling is not the same as the one from python or c library. I have run into similar problems. It might be a timing problem here, so at the point when the java code reaches the lines to read the reply from the seonsor it is allready too late, and the response was allready done....
by RyuKajiya
Mon Nov 17, 2014 7:01 pm
Forum: Java
Topic: Read time it takes to reach pin state using pi4j
Replies: 0
Views: 546

Read time it takes to reach pin state using pi4j

I am trying to read simple light data from a photo resistor. As many tutorials show, you can link a photoresistor with a 1uF condensator, then connect a GPIO pin in between and measure the time it takes for the pin to reach logic low. The easiest code i found is for phyton: #!/usr/bin/env python # E...
by RyuKajiya
Sat Nov 15, 2014 6:18 pm
Forum: Troubleshooting
Topic: How to check if DS18B20 works ?
Replies: 14
Views: 4647

Re: How to check if DS18B20 works ?

And works like a charm too.
Moved the pin to GPIO20 of B+ RPi, and rading both sensors i have connectec like with GPIO4.
Just make sure that command is added to same line that is allready there in the file. It looks like it does not like a line feed.
by RyuKajiya
Sat Nov 15, 2014 3:57 pm
Forum: Troubleshooting
Topic: How to check if DS18B20 works ?
Replies: 14
Views: 4647

Re: How to check if DS18B20 works ?

Might have to do that on at least one of my RPis because have a touchscreen on it that connects to first 16 pins of the GPIO and i doubt that i can hijack the pin for both.
by RyuKajiya
Sat Nov 15, 2014 3:02 pm
Forum: Troubleshooting
Topic: How to check if DS18B20 works ?
Replies: 14
Views: 4647

Re: How to check if DS18B20 works ?

Hah, ok, works!
The room on my experiment breadboard is getting crowded, but have 2 sensors working.

Thanks for the help!
All those tutorials i found failed to point out that it only works with that pin.
Thought they only used that because it is first one along the port.
by RyuKajiya
Sat Nov 15, 2014 2:52 pm
Forum: Troubleshooting
Topic: How to check if DS18B20 works ?
Replies: 14
Views: 4647

Re: How to check if DS18B20 works ?

Ok, connected it to GPIO4 and i get a folder for the temperature sensor now.
But how do you use multiple sensors when it only works on one pin ?
by RyuKajiya
Sat Nov 15, 2014 2:44 pm
Forum: Troubleshooting
Topic: How to check if DS18B20 works ?
Replies: 14
Views: 4647

Re: How to check if DS18B20 works ?

Sorry, that was a typo, yes, i use w1-gpio and w1-therm.
But never read that it must be a specific pin. All the tutorials say you can even connect several sensors, so it has to work with different pins.
by RyuKajiya
Sat Nov 15, 2014 2:14 pm
Forum: Troubleshooting
Topic: How to check if DS18B20 works ?
Replies: 14
Views: 4647

Re: How to check if DS18B20 works ?

Image

Link to larg image: http://s29.postimg.org/szdqs0tav/20141115_150712.jpg


Flat cable is connected to GPIO port as usual.

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