Linux embedded plus small TFT: ready-to-use solution

edward.ming.lee@gmail.com writes:
> Tablet is not for embedded.  It's difficult set up default behaviors
> and hard to hook up I/Os.

I meant just use the tablet as a display, communicating with an external
board that runs the application.  The tablet wouldn't need special code,
if a web browser can supply sufficient UI features.

On Thursday, September 8, 2016 at 6:22:35 PM UTC-7, Paul Rubin wrote:
> edward.ming.lee@gmail.com writes:
> > Tablet is not for embedded.  It's difficult set up default behaviors
> > and hard to hook up I/Os.
> 
> I meant just use the tablet as a display, communicating with an external board that runs the application.  The tablet wouldn't need special code, if a web browser can supply sufficient UI features.

Yes, we do use phone/tablet as UI, communicating with an external interface board, and that interface board is the Raspberry Pi 3.  In addition, the RP3 boot up web connected and running a frame buffer web browser (net-surf) to show system status.  This interface board does not need UI, but plenty of digital (64) and analog I/O (10), using stackable I/O expanders.

X11/firefox are too heavy for RPI.  Framebuffer/net-surf are good enough, if i can get rid of the top title-bar and bottom status-bar (virtual framebuffer device?), or just cover them with some panels.  

edward.ming.lee@gmail.com writes:
>> if a web browser can supply sufficient UI features.
> X11/firefox are too heavy for RPI.

I'm suggesting using the tablet's built-in web browser as a front end
for an RPI program that's set up as a web server application.  Sorry if
that wasn't clear.  Are you working with pozz on this?

If you really want to run a browser on a rpi, There are some much
lighter weight ones around than Firefox, depending on what functionality
you need.  I've played with Dillo (www.dillo.org) which is very fast.
It's supposedly included in Raspbian.

On Thursday, September 8, 2016 at 7:03:51 PM UTC-7, Paul Rubin wrote:
> edward.ming.lee@gmail.com writes:
> >> if a web browser can supply sufficient UI features.
> > X11/firefox are too heavy for RPI.
> 
> I'm suggesting using the tablet's built-in web browser as a front end for an RPI program that's set up as a web server application.  

Yes, our RPI is a web server, but it also run a web browser to show system status and no need for input UI.

> Are you working with pozz on this?

No, we just have similar requirements.

> If you really want to run a browser on a rpi, There are some much lighter weight ones around than Firefox, depending on what functionality you need.  I've played with Dillo (www.dillo.org) which is very fast. It's supposedly included in Raspbian.

We are looking into the framebuffer version of NetSurf.  It fits what we need, other than the extra title-bar, status-bar and mouse pointer that we need to get rid of.

Il 09/09/2016 01:32, Paul Rubin ha scritto:
 > pozz <pozzugno@gmail.com> writes:
 >> I think it's very difficult to find a small display with HDMI 
connection.
 >
 > 5 inch is easy to find--does yours have to be smaller?

It is somewhat big for my application, anyway I will check it.  Could 
you suggest a plastic enclosure for RPI board, display and a custom 
board where to put AC/DC and 4G modem?

All the RPI enclosures I found don't have additional space for other boards.


 > Could you
 > consider using a small Android tablet or something similar?

No, I'd like to use a single device.


 >> Do you know if cdc_acm is included in Raspberry Pi Linux kernel?
 >> Have you tried to send AT commands to your modem?
 >
 > Don't know if it's in the raspberry pi kernel but Linux has supported it
 > forever, at least as a loadable module.  I've never used it myself 
though.
 >

pozz <pozzugno@gmail.com> writes:
> Could you suggest a plastic enclosure for RPI board, display and a
> custom board where to put AC/DC and 4G modem?

I don't have specific recommendations.  I could surf around a bit but
you can do the same.  Adafruit.com and Digikey.com are good places to
start.