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Before shooting this down as expensive can we stick to comparing like with like, the device is intended to have a long life span so educators can build quality

by tudorw 11y ago

Before shooting this down as expensive can we stick to comparing like with like, the device is intended to have a long life span so educators can build quality teaching resources based on the platform.

rwmj 11y ago
Expensive? $60 seems really cheap.
- dagw 11y ago
  There are a ton of Chinese brands that sell rasperryPi compatible touch screens (of very varying quality) at half the price. That being said if I actually needed a touch screen for a rasperryPi I wouldn't hesitate to spend $60 on an official screen and save myself a lot of potential hassle.
  - noonespecial 11y ago
    You are very right with this. I've bought plenty of both. What it comes down to is that if you just want one to make a cool project or experiment with, buy the official one. The extra $ is worth it and then some on saved hassle. If you need to rig up half a dozen, or its something you want to build over and over, it starts to become worth it deal with the hassle of learning the quirks of the chinese parts.
  - Yaggo 11y ago
    The most of cheap "rasperryPi compatible touch screens" use SPI interface (GPIO) which has very limited data rate, only suitable for 320x240 / low FPS graphics without any kind of HW acceleration. HDMI compatible touch screen are typically more expensive than $60. The official RPi display is great because it uses the onboard display connector (which has been useless this far).
    - userbinator 11y ago
      typically more expensive than $60 No, you can certainly get them for less than that: http://www.aliexpress.com/item/Tontec-7-Raspberry-Pi-LCD-Touch-Screen-Display-TFT-Monitor-AT070TN90-with-Touchscreen-Kit-HDMI-VGA/1692887583.html http://www.aliexpress.com/item/Tontec-7-Raspberry-Pi-LCD-Tou...
      - Gracana 11y ago
        The $60 RPi screen is higher resolution, mounts with four screws (vs this one with three separate PCBs plus the LCD), and has an interface designed to be controlled by the RPi GPIO pins. I don't think saving $17 is worth losing all of that.
        ne0n 11y ago
        These are 7-inch capacitive touch screens, less than $70 from amazon prime, same resolution (800x480), mount with 4 screws, and use HDMI for video and USB for power/touchscreen. The downside is that the touchscreen drivers are binaries. Somebody online made an open source driver that appears to work perfectly, so if you're not using Raspbian or something else their binaries are made for, you might have some driver hacking to do. http://www.amazon.com/Waveshare-Capacitive-Interface-Android4-2-2-Beaglebone/dp/B00XV9QDNK http://www.amazon.com/Waveshare-Capacitive-Interface-Android... http://www.amazon.com/SainSmart-Touch-Screen-Display-Raspberry/dp/B00XXOUIE8 http://www.amazon.com/SainSmart-Touch-Screen-Display-Raspber... http://www.april1985.com/post/2015-06-28-hack-waveshare-touchscreen/ http://www.april1985.com/post/2015-06-28-hack-waveshare-touc...
    - makomk 11y ago
      Interestingly, the controller on all those displays can actually talk DPI, it's just never pinned out - and there are probably even cheaper DPI-only displays out there, judging from the price of devices that use them. Unfortunately they seem to be really difficult to get hold of.
- makomk 11y ago
  It's more expensive than an entire low-end Android tablet with a similar capacitive touch screen.
whiskers 11y ago
It's also pretty great as a screen for your development/hacking Pi when you need to debug issues. I use two 27" monitors on VESA arms and the display is short enough that I can just tuck it underneath. The relative low dot pitch means text is very readable in the terminal without any configuring. I actually really love it (and I didn't expect to when I first saw it...)
- paines 11y ago
  Can you comment on the weight and handling if used as a tablet for lets say reading, couch surfing, etc.... many thanks!
  - whiskers 11y ago
    Not ideal for tablet use as the back isn't flat (Pi and driver board attached to it). You'd also need a power supply! I don't have any scales to hand but with screen + Pi + driver it feels about as heavy as my iPad Air. It's great as a mini screen for your Pi though. :-)
  - MarcScott 11y ago
    Not the thinnest tablet in the world but... https://twitter.com/clivebeale/status/641165826016604160 https://twitter.com/clivebeale/status/641165826016604160
slug 11y ago
If they were using standard connectors for the display, why would having long life span be useful? I can just use a newer one (better specs) when time comes and can swap with a new one from another vendor if needed be. I spent this weekend creating a small micro-controller system (freescale uC) with an attached tft lcd+touch, the latter cost me less than a 1/4 of this display and uses standard connections and readily available datasheets. In their own words, the raspberry pi display uses interface signals that most other manufactures shunned due to several issues (EMI,etc) and their connector is hard to find on any other sbc currently in the market. The display is huge compared to the raspberry pi board, what is the use case, considering the low resolution? Why go through all the trouble of using the connector on the pi instead of its other standard hdmi port ?
- joezydeco 11y ago
  I think we're confusing "lifetime" in the reliability sense with "lifetime" meaning how long this particular LCD part will be available from the supplier. I've been working with these types of LCDs for a long time, and when it comes to these WVGA/SVGA 7" units you can get a ton from Asia at great prices but the factory will literally disappear in a few months. The LCD fabs constantly get bought/sold/churned as the major players like Sharp and LG shed off their last-generation fabs and the other smaller fish scoop them up. Ideally a group like RPi will want to have the same part available for a long time so that they don't need to create new revisions of the interface cables, power supplies, or software drivers to handle the change. It's nearly impossible to autodetect one 7" LCD from another via software so you need to configure it entirely in a bootloader or kernel configuration line. And then that becomes a massive support issue.

by tudorw 11y ago

rwmj 11y ago

Expensive? $60 seems really cheap.

dagw 11y ago
There are a ton of Chinese brands that sell rasperryPi compatible touch screens (of very varying quality) at half the price. That being said if I actually needed a touch screen for a rasperryPi I wouldn't hesitate to spend $60 on an official screen and save myself a lot of potential hassle.
- noonespecial 11y ago
  You are very right with this. I've bought plenty of both. What it comes down to is that if you just want one to make a cool project or experiment with, buy the official one. The extra $ is worth it and then some on saved hassle. If you need to rig up half a dozen, or its something you want to build over and over, it starts to become worth it deal with the hassle of learning the quirks of the chinese parts.
- Yaggo 11y ago
  The most of cheap "rasperryPi compatible touch screens" use SPI interface (GPIO) which has very limited data rate, only suitable for 320x240 / low FPS graphics without any kind of HW acceleration. HDMI compatible touch screen are typically more expensive than $60. The official RPi display is great because it uses the onboard display connector (which has been useless this far).
  - userbinator 11y ago
    typically more expensive than $60 No, you can certainly get them for less than that: http://www.aliexpress.com/item/Tontec-7-Raspberry-Pi-LCD-Touch-Screen-Display-TFT-Monitor-AT070TN90-with-Touchscreen-Kit-HDMI-VGA/1692887583.html http://www.aliexpress.com/item/Tontec-7-Raspberry-Pi-LCD-Tou...
    - Gracana 11y ago
      The $60 RPi screen is higher resolution, mounts with four screws (vs this one with three separate PCBs plus the LCD), and has an interface designed to be controlled by the RPi GPIO pins. I don't think saving $17 is worth losing all of that.
      - ne0n 11y ago
        These are 7-inch capacitive touch screens, less than $70 from amazon prime, same resolution (800x480), mount with 4 screws, and use HDMI for video and USB for power/touchscreen. The downside is that the touchscreen drivers are binaries. Somebody online made an open source driver that appears to work perfectly, so if you're not using Raspbian or something else their binaries are made for, you might have some driver hacking to do. http://www.amazon.com/Waveshare-Capacitive-Interface-Android4-2-2-Beaglebone/dp/B00XV9QDNK http://www.amazon.com/Waveshare-Capacitive-Interface-Android... http://www.amazon.com/SainSmart-Touch-Screen-Display-Raspberry/dp/B00XXOUIE8 http://www.amazon.com/SainSmart-Touch-Screen-Display-Raspber... http://www.april1985.com/post/2015-06-28-hack-waveshare-touchscreen/ http://www.april1985.com/post/2015-06-28-hack-waveshare-touc...
  - makomk 11y ago
    Interestingly, the controller on all those displays can actually talk DPI, it's just never pinned out - and there are probably even cheaper DPI-only displays out there, judging from the price of devices that use them. Unfortunately they seem to be really difficult to get hold of.
makomk 11y ago
It's more expensive than an entire low-end Android tablet with a similar capacitive touch screen.

whiskers 11y ago

It's also pretty great as a screen for your development/hacking Pi when you need to debug issues. I use two 27" monitors on VESA arms and the display is short enough that I can just tuck it underneath. The relative low dot pitch means text is very readable in the terminal without any configuring. I actually really love it (and I didn't expect to when I first saw it...)

paines 11y ago
Can you comment on the weight and handling if used as a tablet for lets say reading, couch surfing, etc.... many thanks!
- whiskers 11y ago
  Not ideal for tablet use as the back isn't flat (Pi and driver board attached to it). You'd also need a power supply! I don't have any scales to hand but with screen + Pi + driver it feels about as heavy as my iPad Air. It's great as a mini screen for your Pi though. :-)
- MarcScott 11y ago
  Not the thinnest tablet in the world but... https://twitter.com/clivebeale/status/641165826016604160 https://twitter.com/clivebeale/status/641165826016604160

slug 11y ago

If they were using standard connectors for the display, why would having long life span be useful? I can just use a newer one (better specs) when time comes and can swap with a new one from another vendor if needed be. I spent this weekend creating a small micro-controller system (freescale uC) with an attached tft lcd+touch, the latter cost me less than a 1/4 of this display and uses standard connections and readily available datasheets. In their own words, the raspberry pi display uses interface signals that most other manufactures shunned due to several issues (EMI,etc) and their connector is hard to find on any other sbc currently in the market. The display is huge compared to the raspberry pi board, what is the use case, considering the low resolution? Why go through all the trouble of using the connector on the pi instead of its other standard hdmi port ?

joezydeco 11y ago
I think we're confusing "lifetime" in the reliability sense with "lifetime" meaning how long this particular LCD part will be available from the supplier. I've been working with these types of LCDs for a long time, and when it comes to these WVGA/SVGA 7" units you can get a ton from Asia at great prices but the factory will literally disappear in a few months. The LCD fabs constantly get bought/sold/churned as the major players like Sharp and LG shed off their last-generation fabs and the other smaller fish scoop them up. Ideally a group like RPi will want to have the same part available for a long time so that they don't need to create new revisions of the interface cables, power supplies, or software drivers to handle the change. It's nearly impossible to autodetect one 7" LCD from another via software so you need to configure it entirely in a bootloader or kernel configuration line. And then that becomes a massive support issue.