video transmitter / receiver using MCU

[jeyes56]

Hi guys,

is it possible to make a video transiver using a MCU?

somebody says that the Inductor can be replaced by an oscillator, is it true?

 

[trash]

It depends on what you are thinking of.
If for example you're talking about generating a simple video signal with an MCU, then that is fairly easy.
It requires that you know something about how an analog video signal is constructed.

To generate a simple black and white picture is easiest.
Starting with a horizontal sync pulse and then black or white levels 1Vpp. Two digital outputs is enough to achieve this with a few extra components.

Horizontal lines without any vertical sync will produce a result on any monitor. But to get the picture to lock correctly you will need to construct a full frame.
say 525 lines of non interlaced video. A black and white NTSC type frame.

You can then expand on this basic approach to generate a grey scale picture instead of a binary black and white using simple D2A techniques.
If your MCU is fast enough a direct synthesis of the colour subcarrier can be generated but by this stage is becomes easier just to farm RGB off to another chip or device to generate a baseband colour video signal.

Back in the days of Z80 I wrote some simple games for the old turret tuner TV. It didn't have a composite video in so I made a simple FET VHF oscillator which worked about ch1 and amplitude modulated it with the B&W composite signal. Sadly I was about 10 years behind pong.


I'm not sure what your getting at by suggesting an inductor can be replaced by an oscillator ?

 

[jeyes56]

transmitter, for example:
i would like to send a video from a serial camera to TV receiver, is it possible?

receiver, for example:
i would like to receive a video transmitted through TV frequency, and view it on computer, is it possible?


with frequency selector to change the frequency.

what should i do first, or consider in making this kind of transiver?

 

[3v0]

I am confused.

If you have a TV camera with a serial data output and you want to view it on a computer why do you need to convert the signal to a 'TV Frequency'. Seems it would be much easier to send the digital data over the radio link.

 

[trash]

I don't know what the data rate is out of a serial camera, but to transmit this digital video is going to be complex.

You'd do better with an analog camera and video sender/receiver and a video capture card.
How far to do you want to transmit the video ?

 

[3v0]

I don't know what the data rate is out of a serial camera, but to transmit this digital video is going to be complex.

You'd do better with an analog camera and video sender/receiver and a video capture card.
How far to do you want to transmit the video ?

Not so much complex as a lot of it. Just depends on the resolution and frame rate.

Could be a camera like this linksprite
https://www.sparkfun.com/products/10061

 

[ronsimpson]

The SparkFun camera has hardware hand shake and maybe software hand shake so talking to it is easy.

I can not tell if the JPEG compression can be turned off. I could use it with no compression.

 

[trash]

38.4kbps is a little tricky.
What kind of transmitter and receiver would you recommend ?

I can think of several methods to do the job, but they are either simpler just to send analog video or more complex in terms of modulation and demodulation
of a serial data signal.

 

[3v0]

We do not know enough about what jeyes56 is attempting to do. Most important what the camera is and how he intends to use it. Without that we are only guessing. Given that it has a serial output I am guessing the data rate is no where near full blown video. But lets let him tell us.

 

[ronsimpson]

Jeyes56 has not been back for a while. The SparkFun camera will not do motion pictures.
The speed is set by:
1) the baud rate, which can be very fast to very slow
2) by the resolution.
3) by the compression At 100:1 the pictures are small but not pretty. At 23:1 they look good.

 

[be80be]

I install video Video Systems some camera use wifi. They use Arm micros and the video is live full color.

They work like web cams sending the data out HTTP web sever

Arm for the web sever sending out video with wifi then the receiver is a cheap PC main broad most have 1.5GHz and this then sends it to whatever you want TV CRT

 

[be80be]

Here you go get two of these $35 each not bad **broken link removed**

The Raspberry Pi is a credit-card sized computer board that plugs into a TV and a keyboard. It’s a miniature ARM-based PC which can be used for many of the things that a desktop PC does

Features:
Broadcom BCM2835 700MHz ARM1176JZFS processor with FPU and Videocore 4 GPU
GPU provides Open GL ES 2.0, hardware-accelerated OpenVG, and 1080p30 H.264 high-profile decode
GPU is capable of 1Gpixel/s, 1.5Gtexel/s or 24GFLOPs with texture filtering and DMA infrastructure
256MB RAM
Boots from SD card, running the Fedora version of Linux
10/100 BaseT Ethernet socket
HDMI socket
USB 2.0 socket
RCA video socket
SD card socket
Powered from microUSB socket
3.5mm audio out jack
Header footprint for camera connection
Size: 85.6 x 53.98 x 17mm

Oh and get some cheap usb wifi card