====== PiCam ======

Tilt-Pan autonomous camera for timelaps acquisition based on a Raspeberry-pi.



===== Concept =====

The first prototype proved the feasibility. It was based on a tilt-pan module (2x SG90 micro-servo) + raspberry-pi camera v1 with CS lens mount.

http://imagizer.terre-adelie.org/2016-08-02-Vesteralen/page3/22h23m39-NIKON_D5100.jpg

Some resulting videos are:
http://video.terre-adelie.org/2016/2016-08-04-Melbu/video_4.mp4

===== Basis =====
The new basis is made of 9x9mm beech wood sticks (hetre) + 3d printed basis, RPi holder and servomoter holder.
The scheme is available and here is a photo ...
http://imagizer.terre-adelie.org/2016-11-06/11h02m45-NIKON_D800.jpg

===== PWM generator =====

"Servo Pi - PWM Controller" from Kubii, actually a PCA9685 PWM I2C controler, 16 channels, 12 bits each (4096 values).

===== Panorama servo =====

DSS-M15S from DFRobot.

PWM frequency: 300 Hz,

||valeur				||	deg||
||525			||		98||
||550			||		97||
||600			||		90||
||700			||		80||
||800			||		69||
||900			||		59||
||1000			||		48||
||1100			||		38||
||1200			||		27||
||1300			||		16||
||1400			||		5||
||1500			||		-5||
||1600			||		-16||
||1700			||		-27||
||1800			||		-37||
||1900			||		-47||
||2000			||		-57||
||2100			||		-67||
||2200			||		-77||
||2300			||		-87||
||2400			||		-98||
||2500			||		-108||
||2600			||		-119||
||2700			||		-130||
||2800			||		-140||
||2900			||		-150||
||3000			||		-160||
||3100			||		-171||
||3200		||		-180||
||3300		||		-190||
||3350		||		-195||

Those are raw values. PWM values needs to be converted in µs (300Hz, 4096 steps ...) but the data look rather linear which is great.
To simplify, we have a linear behavour:
||Timing || angle||
|| 420 µs|| 98° ||
|| 2710µs||-195°||