Featured Articles
Announcing Pi
Technical Specifications
Raspberry Pi FAQs
Win a Pi
Raspberry Pi Wishlist
Actions
Forum Thread Details
  • Replies 10 replies
  • Subscribers 677 subscribers
  • Views 934 views
  • Users 0 members are here
Related

Would this work for a handheld DVR?

Former Member

Hello All, I plan to develop a small handheld digital video recorder, and it looks like the Raspberry Pi might be just the piece of base-kit I've been looking for!

 

For the basic device, I need to connect an LCD touchscreen to it, which I would guess I can do via one of the USB ports, and a composite video (CVBS) input.  For future use, I'll need ADC and CAN-comms inputs, but that all looks fairly straight-forward, based on what I can see from the specs docs.

 

I was looking at the Beagleboard for this initially, but I hope to make small batch production runs with it for a business start-up.  The Beableboard people repeatedly say that it's not suitable for production runs, but don't say why unfortunately, so that's why I'm now pinning my hopes on the Raspberry Pi.

 

Can anyone out there help me out with these questions:...?

- From reading through the spec and some of the posts here, it looks like there is plenty of power to decompress a digital-video file and drive out a video stream to the HDMI or Video port, but what about the other way around - compressing a video input stream?  Is the MIPS of the ARM core and the available memory on the Raspberry Pi board enough to compress a video input stream (probably H.264), in readiness for storage to some kind of mass media (SD-Card, or possibly a USB SDD)?
- I see that there is something called a 'Camera Port' on-board, but can't find out much about it - is this suitable for composite video input, or is it for something else entirely?
- In case I can't connect a CVBS signal straight into the board, for a backup I've also been looking for a piece of hardware that I could use for digitising a CVBS input into a USB port, but the only one I've found that's even close to what I need costs a small fortune, and knocks my target price for six!  I want to get hold of somethig like those cheap bits of video=>PC conversion gadgets that are in abundance on eBay (etc), but that also allows integration into other systems.  Does anyone in the community know of such a thing for around £20?
- I want to use a touchscreen input to side-step the logistical complexity of having user-buttons read into the GPIO ports - is USB the only way I'm likely to be able to get a touchscreen input into the Raspberry Pi, or does anyone know of a device that would enable me to hook a touchscreen up to an interface that's already on the board?
- Lastly, is the Raspberry Pi suitable for what I want to do, or would I still be better off looking at the Beagleboard, or even Beaglebone?

 

The Raspberry Pi looks like a fantastic peice of equipment for this kind of thing - and it's British - and I'd love to be able to use it for my project, so any help or advice would be greatly appreciated.

 

Doug Ponsford.

Parents

  • THe RPi is completely unsuitable for this kind of thing:

     

    You are talking about "small batch production runs with it for a business start-up" - the RPi project is currently not a source of anything but even if they sort out the current problems it would be a poor basis for a serious product because the RPi project has no commitment to being a source of OEM boards.

     

    But it's a bad choice for other reasons -  the IO is very limited and you will have dififculty interfacing CAN or high performance ADC to it.

     

    I don't know if it will do the video stuff you want.

     

    AFIK The Beaglebone design can be cloned (check this before making too much comitment) so if it works for your project you can make your own custom boards if you get to production.

     

    But  I'm puzzled - what will be special about your device - if you Google for handheld dvr you find zillions of products form about £30 upwards - it looks like a dificult market to penetrate with a solution made of plugged together retail devices. You'll be up against people who are happy to develop custom chips but you're worried about the complexity of reading buttons via GPIO.

     

    Michael Kellett

  • in reply to michaelkellett

    @ Michael, Thanks for your comments.

     

    I did think that the RPI wouldn't be well supported, as it's primarily designed for teaching kids about computing, so your (and others) comments about lack of production support in the future confirm my suspicions.

     

    ADC or CAN would be connected via I2C/SPI, so that would be quite easy.  I had assumed that there would be some kind of Board Support Package available via the Linux community, but it seems that this is also some way off (if at all), so it does look like the RPI would be unsuitable for anything other than a one-off homer project.

     

    As for why I would want to try to compete with the major ASIC manufacturers - I don't!  The myriad cheap devices that you can get anywhere aren't suitable for my target market - sports use. None of the devices you can buy cheaply allow an external CVBS video source to be input (which is important for siting a small bullet camera in a small space on the inside of a race fairing, or on a roll-cage - and imagine trying to ride a mountain bike downhill one-handed, while taking video shots on a mobile-phone with the other!).  Plus, any device with a hard-disk can't withstand the vibration levels you would get in a rally car (most affordable SD-Card video cameras are quite poor quality).

     

    In respect of interfacing buttons to GPIO, you're right that it's a very simple thing to do to just wire up some switches to GPIO, but when you try to fit those switches into a waterproof case, and still make them usable with gloves on, that becomes a whole new problem!  That's why a touch-screen would be the way to go for a waterproof user interface.

     

    Doug.

Reply
  • in reply to michaelkellett

    @ Michael, Thanks for your comments.

     

    I did think that the RPI wouldn't be well supported, as it's primarily designed for teaching kids about computing, so your (and others) comments about lack of production support in the future confirm my suspicions.

     

    ADC or CAN would be connected via I2C/SPI, so that would be quite easy.  I had assumed that there would be some kind of Board Support Package available via the Linux community, but it seems that this is also some way off (if at all), so it does look like the RPI would be unsuitable for anything other than a one-off homer project.

     

    As for why I would want to try to compete with the major ASIC manufacturers - I don't!  The myriad cheap devices that you can get anywhere aren't suitable for my target market - sports use. None of the devices you can buy cheaply allow an external CVBS video source to be input (which is important for siting a small bullet camera in a small space on the inside of a race fairing, or on a roll-cage - and imagine trying to ride a mountain bike downhill one-handed, while taking video shots on a mobile-phone with the other!).  Plus, any device with a hard-disk can't withstand the vibration levels you would get in a rally car (most affordable SD-Card video cameras are quite poor quality).

     

    In respect of interfacing buttons to GPIO, you're right that it's a very simple thing to do to just wire up some switches to GPIO, but when you try to fit those switches into a waterproof case, and still make them usable with gloves on, that becomes a whole new problem!  That's why a touch-screen would be the way to go for a waterproof user interface.

     

    Doug.

Children
No Data