FlashCam:

C++ Library for the PiCamera. Can be used for both video capturing and stills. With a 320x240 resolution, video mode is able to reach 120fps on a RPi Zero Wireless.

September 2017

Library is work in progress, hence this readme is outdated. Currently functional:

• Single frame capturing (capture mode): callback to user defined function with full
• Continous frame capturing (video mode): callback to user defined function per frame.
• Phase Locked Loop (PLL): synchronised Hardware PWM with exposure time of camera. With proper tuning exposure and PWM signal can be synced within 60 microseconds. Only works in video mode.
• OpenGL rendering: Captured frame is not pushed to CPU domain, but stays in GPU, allowing efficient application of OpenGL shaders.

Please see the CmakeLists and tests directory for examples and available tests.

For crosscompilation with this setup, the compilation steps become:

XCS~$ mkdir -p ~/rpi/build/flashcam
XCS~$ cd ~/rpi/build/flashcam
XCS~$ cmake \
-D <SELECT-YOUR-TEST>=ON
-D CMAKE_TOOLCHAIN_FILE=/home/pi/rpicross_notes/rpi-generic-toolchain.cmake \
~/path/to/repository/flashcam/
XCS~$ make
XCS~$ scp flashcam rpizero-local:~/
XCS~$ ssh -X rpizero-local
RPi~$ ./flashcam

Or, when PLL is used (which requires root-acces):

RPi~$ sudo -pc ./flashcam

OLD README:

In progress: addition of flash in both Capture (working) and Video (todo) mode.

Based on:

• picamera
• picam
• raspicam
• raspicam

Requisites

• Crosscompile Environment (but native compilation might be working too)
• GPIO setup / flash

Optional

• OpenCV (used is test-files)

How to use:

For crosscompilation with this setup, the compilation steps become:

XCS~$ mkdir -p ~/rpi/build/flashcam
XCS~$ cd ~/rpi/build/flashcam
XCS~$ cmake \
    -D VIDTEST=ON
    -D CMAKE_TOOLCHAIN_FILE=/home/pi/rpicross_notes/rpi-generic-toolchain.cmake \
    -D CMAKE_INSTALL_PREFIX=/home/pi/rpi/rootfs/usr \
    ~/path/to/repository/flashcam/
XCS~$ make
XCS~$ scp flashcam rpizero-local:~/
XCS~$ ssh -X rpizero-local
RPi~$ ./flashcam

Use VIDTEST=ON or VIDTEST=OFF (default=OFF) to test either the capture or the video mode.

Use PLLTEST=ON (overrides VIDTEST) to test PLL mode of the video stream. This mode uses the hardware PWM (GPIO18) of the Raspberry Pi to generate a PWM pulse with a configurable duty cycle at the set framerate of the camera. Running the PLL-executable requires sudo permissions, hence run as root or with sudo prepended.

When compilin native (NOT TESTED!):

RPi~$ mkdir -p ~/build/flashcam
RPi~$ cd ~/build/flashcam
RPi~$ cmake -D VIDTEST=ON ~/path/to/repository/flashcam/
RPi~$ make
RPi~$ ./flashcam

Test results

RPi~$ ./flashcam 
 -- VIDEO-TEST -- 

Rotation     : 270
AWB          : 1
Flash        : 0
Mirror       : 0
Camera Num   : 0
Exposure     : 6
Metering     : 0
Framerate    : 120.000000
Stabilisation: 0
DRC          : 0
Sharpness    : 0
Contrast     : 0
Brightness   : 50
Saturation   : 0
ISO          : 0
Shutterspeed : 0
AWB-red      : 0
AWB-blue     : 0
Denoise      : 1
Width        : 640
Height       : 480
Verbose      : 0
Update       : 0
Camera-Mode  : 1

...

Timing: 0.008139 (avg: 0.008297; frames: 5880; fps:120.522726)
Timing: 0.007685 (avg: 0.008297; frames: 6000; fps:120.524067)

tuning:

XCS~$ cmake     -D CMAKE_TOOLCHAIN_FILE=/home/pi/rpicross_notes/rpi-generic-toolchain.cmake -DPLLTUNE=ON ~/code/flashcam/
XCS~$ make
XCS~$ scp flashcam rpizero-local:~/
RPi~$ su -pc ./flashcam

Stepresponse:

XCS~$ cmake     -D CMAKE_TOOLCHAIN_FILE=/home/pi/rpicross_notes/rpi-generic-toolchain.cmake -DPLLTUNE=ON -DSTEPRESPONSE=ON  ~/code/flashcam/
XCS~$ make
XCS~$ scp flashcam rpizero-local:~/
RPi~$ su -pc ./flashcam