SparkFun Forums

[bigglez]

Well, in datasheet, it says "JPEG encoded data (8 bit parallel) for full 1.3 Mega data" and "up to 15 fps for every resolution" of course it doesn't have to work at 1.3Mega. I can use smaller resolutions.:)

So the raw data stream is
15 * 1.3 * 8 Megabits per second = 156 Mb/s

The instantaneous bandwidth required is 19.3Mb/s

Added to that you'll need some overhead for
an embedded clock, to arrive at a simple OOK
modulation scheme and simple analog RF link.

I doubt you could do this below microwave
frequencies, so satart looking for a wideband
2.4GHz or 5.8GHz radio link.

The images should be real time to be in control of the robot.:)

So the Tx is omnidirectional
and you have diversity (more than one) Rx?

I don't want to buy a commercial wireless camera set because I'm planning to do some image processing on chip, later on :)

But you still need to buy something as your camera
scheme can't transmit.

[UnforgiveNX]

OK, I see. But I want to concantrate on the rf transmission part

Lets say that I'm making the cam to work at 352x288 resolution. Now, 15fps * 0.1 * 8 = 12 Mb/s which makes about 1.5Mb/s for instantaneous bandwidth.

By which means can I transfer this image to the pc in a suitable range (about 100m)? Again 2.4GHz band? Smt. like Xbee modules?

Btw, I couldn't get what you mean with "So the Tx is omnidirectional
and you have diversity (more than one) Rx? ". Sorry for that.

I'm a bit newbie in RF communication

[bigglez]

OK, I see. But I want to concantrate(sic) on the rf transmission part

Or, pick up a book about communication theory
- RF is only a small part of your proposed project.

Lets say that I'm making the cam to work at 352x288 resolution. Now, 15fps * 0.1 * 8 = 12 Mb/s which makes about 1.5Mb/s for instantaneous bandwidth.

Okay.

By which means can I transfer this image to the pc in a suitable range (about 100m)? Again 2.4GHz band? Smt. like Xbee modules?

ZigBee (XBEE) is not suitable, due to data rate and range limits:
From the Zigbee Wikipedia entry:
The raw, over-the-air data rate is 250 kbit/s
per channel in the 2.4 GHz band, 40 kbit/s per
channel in the 915 MHz band, and 20 kbit/s in
the 868 MHz band.
Transmission range is between 10 and 75 meters
(33 and 246 feet), although it is heavily dependent
on the particular environment. The maximum
output power of the radios is generally 0 dBm
(1 mW).

Btw, I couldn't get what you mean with "So the Tx is omnidirectional
and you have diversity (more than one) Rx?

For a wideband data channel the RF carrier has to be quite
high in frequency (so that the modulating frequency is a
small ratio to carrier frequency). Unless you can get a
license from the Gov'mnt you will have to operate your
transmitter in an ISM band.

The most popular are 2.4GHz and 5.8GHz. The RF
propagation of these bands has limits on link quality,
in particular multi-path reception or LOS blocking,
which are overcome in most cases by diversity.
Because your transmitter is mobile
it will require an omni-directional antenna, further reducing
the ERP (Effective Radiated Power) in order to provide 360deg
coverage.

I'm a bit newbie in RF communication

Perhaps you should consider an intermediate project better
suited to building your skills?