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General Misc => Misc => Topic started by: Joker94 on May 27, 2010, 05:05:16 PM

Title: AV signal to UART
Post by: Joker94 on May 27, 2010, 05:05:16 PM
Hi guys

How complicated is it to get a AV signal from a FPV camera and feed the video data into a UART port?

Will i need to digitise the signal through a microprosessor?

Thanks for you help

Joker94
Title: Re: AV signal to UART
Post by: Razor Concepts on May 27, 2010, 05:19:54 PM
Just note that thse little avr chips wont be able to process real time video in decent quakity because they are too slow.

Search for the avr tetris project, it was just featured on hack a day, the people managed to get b/w video in low resolution into a mega644
Title: Re: AV signal to UART
Post by: madsci1016 on May 27, 2010, 06:04:29 PM
Hi guys

How complicated is it to get a AV signal from a FPV camera and feed the video data into a UART port?

Will i need to digitise the signal through a microprosessor?

Thanks for you help

Joker94

Hmm, unless I am not understanding your question, the answer is you can't.

Are you asking if you can simply wire an analog video signal to a microcontroller uart port?

To capture a analog video signal, you will need a video capture device that captures analog video and converts it into a digital video stream.

But like Razor said, one you start dealing with digital video, most microcontrollers used around here are not going to cut it.
Title: Re: AV signal to UART
Post by: Joker94 on May 27, 2010, 07:04:51 PM
Sorry about the vague discription if the first post. I was in a rush.

What's happening is i am part of the team competing in a UAV competition and i have been made head electrical tech. What we have is a micro pilot autopilot system which sends all the data from all the sensors back to the base station. They have cameras that go with it but they are 20 000 on wards so it is out of our price range. From what i ahve read it connects to a UART type port of the internal microprocessor.

I Have an FPV camera that i have to get integrated into the micro pilot system. The video signal from this camera is outputted by a AV signal.

From what you guys ahve said i need to digities the signal for a microprocessor to transmit the video. You have also said that the processr might not be able to process the data fast enough. They want it to go through the micro pilot system but if when i have done it it is not upto our standards we have a 1.2ghz video transmitter that we can use.

We want to try the video through the auto pilot first as we need to do all we can to save weight and space in the plane.

Thanks for your help, all suggestions welcom

Joker94
Title: Re: AV signal to UART
Post by: Joker94 on May 27, 2010, 07:11:52 PM
So what i could potentially do is use a capture device like this one

http://www.altoedge.com/video/video-to-usb-easycap.html (http://www.altoedge.com/video/video-to-usb-easycap.html)

not that exact one but something similar. Then have a USB to UART chip like used on the arduinos to get the camera data to the uart port.

I know it will take some custom circuitry. And i am not sure if it will be fast enough for video considering it takes a few seconds to upload a sketch to the arduino.

But start off with something like the video capture device like i pointed out?
Title: Re: AV signal to UART
Post by: Joker94 on May 27, 2010, 07:13:49 PM
This is the auto pilot system. We are using the MP2128.

http://www.micropilot.com/ (http://www.micropilot.com/)

and the camera is just a FPV cam i will  post later.
Title: Re: AV signal to UART
Post by: Admin on May 31, 2010, 08:39:09 AM
In addition to the other comments, here is another route you can take:
http://www.societyofrobots.com/robot_faq.shtml#camera_microcontroller (http://www.societyofrobots.com/robot_faq.shtml#camera_microcontroller)
Title: Re: AV signal to UART
Post by: Joker94 on June 01, 2010, 02:27:03 AM
Cheers Admin

We are just going to go with a general AV camera with a standard AV transmitter

Cheers

Joker94
Title: Re: AV signal to UART
Post by: dunk on June 01, 2010, 02:44:10 AM
We are just going to go with a general AV camera with a standard AV transmitter
make sure you pick an AV transmitter that operates on a different band (not just a different channel) to your data link.
 the FPV (First Person View) section of rcgroups.com is a good place for advice on AV transmitters and receivers.
http://www.rcgroups.com/video-piloting-fpv-rpv-469/ (http://www.rcgroups.com/video-piloting-fpv-rpv-469/)


dunk.
Title: Re: AV signal to UART
Post by: Joker94 on June 01, 2010, 03:43:22 AM
Cheers Dunk

Yeah i know about that sorta stuff, and the Aussie broadcasting laws say we can use a Ghz signal up to 4 w if we use digital modulation on the video signal.

We have a person from my local flying club helping us out. He flies and has flown FPV planes and gliders for many years.

Cheers

Joker94