tv tuner for pc

[ervinpm]

hi everyone!

I'm an electronics and communications engineering student, we are currently making our thesis project... our instructor approved our proposal entitled "TV tuner for PC." I am having trouble where to start. Can anyone suggest how will we be able to do this project?
The project requires a finished prototype. We were planning on using USB connection to make the tuner external but still we have no idea of how to do it. I hope that this forum can help us.

 

[Nigel Goodwin]

hi everyone!

I'm an electronics and communications engineering student, we are currently making our thesis project... our instructor approved our proposal entitled "TV tuner for PC." I am having trouble where to start. Can anyone suggest how will we be able to do this project?
The project requires a finished prototype. We were planning on using USB connection to make the tuner external but still we have no idea of how to do it. I hope that this forum can help us.

There are a number of very different problems here?.

1) Making a digitally tuned TV tuner, you need a tuner, an IF, demodulator etc.

2) The control of the tuner, this is normally done by I2C, so you need to receive the data from USB, read the bits you want, and set the tuner to the correct frequency via the I2C bus, remembering fine tuning, band switching, TV standard etc.

3) Converting the demodulated signal (video and audio) to digital.

4) Send the data to the PC via USB (bearing in mind you can't afford any lapses in communication, and USB is a polled system (no interrupts).

5) Write the PC program to run everything in the PC.

6) Write the microcontroller program to run everything on the tuner board.

It's certainly an interesting and challenging project, but the fact you've had to ask here before you start doesn't inspire me with confidence :lol:

It is, of course, completely impractical, as you can buy commercial units for hardly any money at all - I would imagine the parts will cost you something like ten to twenty times the cost of just buying one. But it's a Uni project, and cost isn't really the point!.

I'm presuming this is a group effort?, in which case you could set different members on different sections?. Personally I would work on building a working TV tuner section first, you could control it via I2C from a PC, in order to fully understand the control system required - feed it's output to a composite monitor, there's no point digitising it until you know you have a fully working tuner section.

 

[ervinpm]

tnx

thanks! now i know where to start... hmm... this project is really making me nutz, do you know where can i look for a schematic diagram of the tuner? i've been surfing the net for it but the only thing that i can find are diagrams for fm tuners...

 

[Nigel Goodwin]

Re: tnx

thanks! now i know where to start... hmm... this project is really making me nutz, do you know where can i look for a schematic diagram of the tuner? i've been surfing the net for it but the only thing that i can find are diagrams for fm tuners...

Thing is it's NOT just a tuner, you need tuner, IF, vision demodulator, audio demodulator, AFC, AGC - to make a functioning receiver.

You could buy a digitally tuner tuner?, and build your own IF around one of the various IC's designed for this job (which these days will probably contain all the rest of the functions as well. Or you could try and buy a complete tuner/IF? - these are commonly used these days, and only require a fairly small number of external components, plus the correct software setting up via the I2C bus.

You need to be trying to find manufacturers datasheets, and also a possible source for the parts - even this part of the project isn't going to be easy!.

 

[ervinpm]

oh ic... i get the picture, i thought we were gonna construct the whole tuner circuit.. i guess i have to start looking for commercially available tuners that uses I2C, thnx dude! one more question, do you know where can i have information about how to program usb devices? so that i can assign my group mate where he can start ^_^

 

[Nigel Goodwin]

oh ic... i get the picture, i thought we were gonna construct the whole tuner circuit.. i guess i have to start looking for commercially available tuners that uses I2C, thnx dude! one more question, do you know where can i have information about how to program usb devices? so that i can assign my group mate where he can start ^_^

It's very difficult to manufacture a tuner, once you get to UHF frequencies it's more plumbing than electronics :lol: Almost all TV manufacturers buy them from component suppliers.

USB is very complicated to use, there's plenty of info about if you look on google, one place you might try is https://www.microchip.com as they have a few PIC's that include USB interfaces, I would suggest you look at the 18F USB series, as they support USB2.0, which you will probably require. MicroChip give details (both PC and PIC) for examples of USB programming.

 

[ervinpm]

hey, i just come up with this wonderful idea, can i get tuners from broken tv or vcr's? then all i have to do is to find its specs? isn't that better than buying a new one?

 

[Nigel Goodwin]

hey, i just come up with this wonderful idea, can i get tuners from broken tv or vcr's? then all i have to do is to find its specs? isn't that better than buying a new one?

It is if you can find the specs on it! - this is usually VERY hard to do.

 

[Jay.slovak]

hi everyone!

I'm an electronics and communications engineering student, we are currently making our thesis project... our instructor approved our proposal entitled "TV tuner for PC." I am having trouble where to start. Can anyone suggest how will we be able to do this project?
The project requires a finished prototype. We were planning on using USB connection to make the tuner external but still we have no idea of how to do it. I hope that this forum can help us.

There are a number of very different problems here?.

1) Making a digitally tuned TV tuner, you need a tuner, an IF, demodulator etc.

2) The control of the tuner, this is normally done by I2C, so you need to receive the data from USB, read the bits you want, and set the tuner to the correct frequency via the I2C bus, remembering fine tuning, band switching, TV standard etc.

3) Converting the demodulated signal (video and audio) to digital.

4) Send the data to the PC via USB (bearing in mind you can't afford any lapses in communication, and USB is a polled system (no interrupts).

5) Write the PC program to run everything in the PC.

6) Write the microcontroller program to run everything on the tuner board.

It's certainly an interesting and challenging project, but the fact you've had to ask here before you start doesn't inspire me with confidence :lol:

It is, of course, completely impractical, as you can buy commercial units for hardly any money at all - I would imagine the parts will cost you something like ten to twenty times the cost of just buying one. But it's a Uni project, and cost isn't really the point!.

I'm presuming this is a group effort?, in which case you could set different members on different sections?. Personally I would work on building a working TV tuner section first, you could control it via I2C from a PC, in order to fully understand the control system required - feed it's output to a composite monitor, there's no point digitising it until you know you have a fully working tuner section.

Nigel, did you know that every ATX PC has I2C bus you can use? (actually it's SMBUS but it's the same). So with little programming skills you can avoid the use of USB. Just thing about it, it's multi-slave serial bus that is freely available...

 

[Nigel Goodwin]

Nigel, did you know that every ATX PC has I2C bus you can use? (actually it's SMBUS but it's the same). So with little programming skills you can avoid the use of USB. Just thing about it, it's multi-slave serial bus that is freely available...

But it's no use for transferring a video signal, I2C is quite slow.

 

[Jay.slovak]

Nigel, did you know that every ATX PC has I2C bus you can use? (actually it's SMBUS but it's the same). So with little programming skills you can avoid the use of USB. Just thing about it, it's multi-slave serial bus that is freely available...

But it's no use for transferring a video signal, I2C is quite slow.

Yes, that true, but you don't use I2C for transfering TV stream but only for adjusting TV tuners parameters. You have to use different bus for stream itself (SPI, Paralel...)

 

[williB]

Nigel, did you know that every ATX PC has I2C bus you can use? (actually it's SMBUS but it's the same). So with little programming skills you can avoid the use of USB. Just thing about it, it's multi-slave serial bus that is freely available...

Built in..?
How, where is it..??

 

[Jay.slovak]

Nigel, did you know that every ATX PC has I2C bus you can use? (actually it's SMBUS but it's the same). So with little programming skills you can avoid the use of USB. Just thing about it, it's multi-slave serial bus that is freely available...

Built in..?
How, where is it..??

Yes, built in.
It's called SMBUS (extended I2C, but fully compatible) and it is used inside for monitoring Temps, controlling FANs, reading SPD chips (RAM config chips), and much more...
All you need is a knowledge of Kernel mode programming and a place on your motherboard to tap into the BUS. (I am very lucky because I have a dedicated SMBUS connector directly on my MB A7N8X DeLuxe). People usually connect to the bus at RAM chips (24xx16 I2Cs)

Is this usefull for you?

 

[williB]

yes , I thought it might have been on the PCI bus ..

 

[Jay.slovak]

yes , I thought it might have been on the PCI bus ..

I don't know, but it is very probable...

 

[Joel Rainville]

You do realize TV tuners for the PC already exist, right?

 

[Jay.slovak]

You do realize TV tuners for the PC already exist, right?

Ofcourse I do, I have one in my PC :lol: (it's the most valuable peripheral that I have)

 

[ervinpm]

it is true that it's already existing but we need to build a new one from scratch for our project, hmm... about i2c bus how do we connect it to the tuner? how can i find the bus on the pc?

 

[Joel Rainville]

it is true that it's already existing but we need to build a new one from scratch for our project, hmm... about i2c bus how do we connect it to the tuner? how can i find the bus on the pc?

But what part of that project are you being evaluated on? You said in your first post that your instructor "approved your proposal entitled TV tuner for PC". Later in the thread, Nigel made you realize that you're probbaly going to have to use a commercial tuner. You are now considering using an I2C bus for some reason... Why not connect directly to the PCI bus? Why not reuse old PCI video cards components? Why not buy the latest ATI All-in-Wonder, scratch the logo off and call it your own?

My point is, what part of the project is relevant and will be evaluated? What part of the project will be different enough from existing TV tuners to be evaluated? I am surprised that this would be accepted as an EE thesis project, since it's been available as a commercial product for so long. Or am I missing an important aspect of your project?

For example, are you expected to write your own software, or can you use someone else's? There's so much freely available software and source code available for this particular purpose...

 

[ervinpm]

the sole purpose is for us to understand the electronics and communication principles undergoing a tv tuner for pc... we would be evaluated if we are really worthy of a bachelors degree by giving us a project that will explain everything that we have learned in our curriculum...