Learning about cameras

I haven’t yet received the GM862-GPS chip, so I’ve been messing around with another important part of the project. Sometimes it will need to be manually controlled it has to carry a webcam. Since I have no idea of how webcams work (except from the view of the user, which is just plugging it to the USB port and start using it) I have to start by finding manuals to understand them.

Soon I found a type of cam that is all I needed; it’s lightweight, cheap, and very low consumption. Those are the so called CMOS Cameras, and they’re widely used in common webcams. Fortunately I had a USB webcam I've never used and that seemed perfect for learning. Once I opened I found the following:


First of all, those six LEDS are not necessary at all (they’re just to illuminate dark rooms). The camera itself is the tiny black square in the middle. Some CMOS cameras available in the Web have integrated lens, but mine not, since it was integrated in the casing. Because of that images are not on focus (unless I put the lens at the right height), but it’s working principle remains the same, so it won’t be a problem to understand how to communicate with it.

The best way to get started is to stop talking and start doing (Walt Disney)

So, let's go.
I will tackle the part I consider to be the hardest (maybe I’m wrong, who knows), and that’s the electronics part. It comprises both navigation and communications. For that purpose I found at SparkFun this kit to use the GM862-GPS chip. In two lines, the GM862-GPS is a communications chip (43 mm. each side) which is able to receive GPS signal. It has algo a built in Python interpreter (quite limited, though). I have some knowledge of Python, but I’ve never programmed a chip through the serial port. I printed a couple of the official manuals (the Hardware and Software User’s Manual) and I’ll try to figure out what can I do with that. It arrives this Friday, so till then I have some time to read the instructions (and prepare some exams, for September, too).

First doodles

I don’t have yet a complete mental image of the finished airship. At first I imagined something not much bigger than one helium balloon (two at most) but soon I realized that it would hardly carry the not-so-heavy navigation electronics. And since an integrated GSM GPS chip costs 120€ I believe that some extra weight for security systems won’t be a bad idea.

So, many different parts require my attention, and since I can’t solve them all at the same time, I should try to organise myself. Operationally I’ve divided the airship in two different sections that can be split in two subsections each.

1. Aerodynamics
a. Lift
b. Propulsion
2. Electronics
a. Navigation
b. Communications

In a general view, lift will be helium’s job, since I need some way to control height (maybe with vertical propellers or with some system to vary volume), propulsion will be carried out by solar powered and internet controlled propellers. It will navigate using GPS (cheap, precise and global range) and communications will use the GSM network (especially GPRS if available). It will be useful to send image using a CMOS camera, since it has to be manually controlled (on landing).