got few more things done on the timelapse robot.
been sorting out the camera's pan/tilt system recently. I've got a couple of servos to use and tried to drive them off the arduino but was a bit unhappy with the resolution and jitter from the arduino. it can do 8 bit pwm, so 256 steps in the servo range kind of course.
what Ive done is make use of some handy MSP430 USB FET debuggers that I had lying around. This is a 10 buck USB debugger and target microprocessor, handy.
Ive made up a little test board to get that system running, what it does it act like an I2C slave and drive a servo using its hardware timers. This way I have 2500 or 3000 steps in the servo range. This has proved to be a LOT more accurate and precise. This will mean we can make minute, precise adjustments to the camera angle day by day. This system is about 80% up and running. few bits more to tidy up and it'll be ready for the arduino to drive it.
the raspberry pi is still going to be in charge of things, as well as driving all the timelapse functions, its going to tell the arduino robot what to do. basically move position or camera pan or tile angle adjustment.
the pi will plug by USB to the arduino, the usb-serial connection will allow the pi to command the arduino robot.
made up a little diagram of whats going or about to be going on to make it more clear ;