I'm looking for a display for a Pi that will work in direct bright
sun, thus I think an LCD of some sort would make sense. I don't
really need colour. just some sort of 'dark on light' to display text
etc.

What's available? Are there any HDMI interface LCD displays?

I could use one of the HD44780 displays driven directly from the Pi
(i.e. not HDMI) but I really want something a little bigger.

Can anyone suggest anything suitable?

--
Chris Green
·

On a sunny day (Wed, 12 Oct 2022 10:23:50 +0100) it happened Chris Green
<cl@isbd.net> wrote in <6mdi1j-blqp.ln1@esprimo.zbmc.eu>:

>I'm looking for a display for a Pi that will work in direct bright
>sun, thus I think an LCD of some sort would make sense. I don't
>really need colour. just some sort of 'dark on light' to display text
>etc.
>
>What's available? Are there any HDMI interface LCD displays?
>
>I could use one of the HD44780 displays driven directly from the Pi
>(i.e. not HDMI) but I really want something a little bigger.
>
>Can anyone suggest anything suitable?

The only displays I know to work in bright direct sunlight are 'e-ink'
displays, those are black on white.
I have seen some projects using those for raspberries, years ago,
maybe googling a bit will find one.

Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:
> The only displays I know to work in bright direct sunlight are 'e-ink'
> displays, those are black on white.
> I have seen some projects using those for raspberries, years ago,
> maybe googling a bit will find one.

There are displays like these:
https://www.waveshare.com/product/raspberry-pi/displays/e-paper.htm
eg
https://www.waveshare.com/7.5inch-e-paper-hat.htm
https://www.waveshare.com/2.13inch-e-paper-hat.htm
https://www.waveshare.com/product/raspberry-pi/displays/e-paper/10.3inch-hdmi-e-paper.htm

But be aware the HAT ones require code to drive them - ie they aren't
intended to display the desktop, but driven from a specific application.
That's probably what you want anyway from an eink display anyway given the
refresh rates.

(there may be Linux drivers to enable an SPI display to show the desktop,
something that would need investigating for your specific display)

Theo

Theo <theom+news@chiark.greenend.org.uk> wrote:
> Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:
> > The only displays I know to work in bright direct sunlight are 'e-ink'
> > displays, those are black on white.
> > I have seen some projects using those for raspberries, years ago,
> > maybe googling a bit will find one.
>
> There are displays like these:
> https://www.waveshare.com/product/raspberry-pi/displays/e-paper.htm
> eg
> https://www.waveshare.com/7.5inch-e-paper-hat.htm
> https://www.waveshare.com/2.13inch-e-paper-hat.htm
> https://www.waveshare.com/product/raspberry-pi/displays/e-paper/10.3inch-hdmi-e-paper.htm
>
> But be aware the HAT ones require code to drive them - ie they aren't
> intended to display the desktop, but driven from a specific application.
> That's probably what you want anyway from an eink display anyway given the
> refresh rates.
>
I'm not wanting to display a desktop, the display is for use on a boat
instrument panel to show things like battery voltages, temperatures
and rudder position.

The above are interesting but the slow refresh is a bit of a nuisance
as the rudder possition display needs to refresh reasonably frequently.

The 10" one is a bit pricey too! :-)

I'll expand a little on what I'm doing:-

On my boat I have a Beaglebone Black (boo, hiss say the Pi
enthusiasts) which monitors the battery voltages, rudder position,
etc. This has a 4 x 40 LCD display inside the boat, close to the BBB
and driven directly by the BBB using its 4-bit data interface.

I want a similar display for the flying bridge which is several metres
away from the BBB. Currently I have a 4 x 20 display driven by RS232
from the BBB but that's a bit flakey and the 4 x 20 display isn't
really enough characters.

So I was considering running an HDMI display off the BBB as HDMI can
do 10 metres or so, however the sun can be very bright, hence asking
this question. It seems not to be a practical solution.

Thus what I think I will do is add a second BBB and put it on the
flying bridge close to a second 4 x 40 LCD display. I already have
wired ethernet so it's easy for BBB number two to get the values from
BBB number one and I already know how to drive the display.

--
Chris Green
·

On a sunny day (12 Oct 2022 13:48:57 +0100 (BST)) it happened Theo
<theom+news@chiark.greenend.org.uk> wrote in
<XBw*U3A0y@news.chiark.greenend.org.uk>:

>Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:
>> The only displays I know to work in bright direct sunlight are 'e-ink'
>> displays, those are black on white.
>> I have seen some projects using those for raspberries, years ago,
>> maybe googling a bit will find one.
>
>There are displays like these:
>https://www.waveshare.com/product/raspberry-pi/displays/e-paper.htm
>eg
>https://www.waveshare.com/7.5inch-e-paper-hat.htm
>https://www.waveshare.com/2.13inch-e-paper-hat.htm
>https://www.waveshare.com/product/raspberry-pi/displays/e-paper/10.3inch-hdmi-e-paper.htm
>
>But be aware the HAT ones require code to drive them - ie they aren't
>intended to display the desktop, but driven from a specific application.
>That's probably what you want anyway from an eink display anyway given the
>refresh rates.
>
>(there may be Linux drivers to enable an SPI display to show the desktop,
>something that would need investigating for your specific display)
>
>Theo

Some years ago I bought a 'Pocket Book Aqua 2' especially for the boat,
it is water-proof and has a 9x12 cm size e-ink black and white display.
The idea was to use its wifi to connect to a raspberry running a web server
or something with a navigation program, I wrote this once:
http://panteltje.com/panteltje/xgpspc/index.html
but there is probably better and more up-to-date software like Navigatrix for example.
As I have no boat ATM (but just spotted a nice one) the project is sort of halted.
Also I was not THAT much impressed with that pocket book aqua, so it is still
'sitting on the dock of the bay' so to speak :-) somewhere, but it could perhaps be a solution.

Dana Wed, 12 Oct 2022 14:42:39 +0100, Chris Green <cl@isbd.net> napis'o:
> Theo <theom+news@chiark.greenend.org.uk> wrote:
>> Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:
>> > The only displays I know to work in bright direct sunlight are 'e-ink'
>> > displays, those are black on white.
>> > I have seen some projects using those for raspberries, years ago,
>> > maybe googling a bit will find one.
>>
>> There are displays like these:
>> https://www.waveshare.com/product/raspberry-pi/displays/e-paper.htm
>> eg
>> https://www.waveshare.com/7.5inch-e-paper-hat.htm
>> https://www.waveshare.com/2.13inch-e-paper-hat.htm
>> https://www.waveshare.com/product/raspberry-pi/displays/e-paper/10.3inch-hdmi-e-paper.htm
>>
>> But be aware the HAT ones require code to drive them - ie they aren't
>> intended to display the desktop, but driven from a specific application.
>> That's probably what you want anyway from an eink display anyway given the
>> refresh rates.
>>
> I'm not wanting to display a desktop, the display is for use on a boat
> instrument panel to show things like battery voltages, temperatures
> and rudder position.
>
> The above are interesting but the slow refresh is a bit of a nuisance
> as the rudder possition display needs to refresh reasonably frequently.
>
> The 10" one is a bit pricey too! :-)
>
> I'll expand a little on what I'm doing:-
>
> On my boat I have a Beaglebone Black (boo, hiss say the Pi
> enthusiasts) which monitors the battery voltages, rudder position,
> etc. This has a 4 x 40 LCD display inside the boat, close to the BBB
> and driven directly by the BBB using its 4-bit data interface.
>
> I want a similar display for the flying bridge which is several metres
> away from the BBB. Currently I have a 4 x 20 display driven by RS232
> from the BBB but that's a bit flakey and the 4 x 20 display isn't
> really enough characters.
>
> So I was considering running an HDMI display off the BBB as HDMI can
> do 10 metres or so, however the sun can be very bright, hence asking
> this question. It seems not to be a practical solution.
>
> Thus what I think I will do is add a second BBB and put it on the
> flying bridge close to a second 4 x 40 LCD display. I already have
> wired ethernet so it's easy for BBB number two to get the values from
> BBB number one and I already know how to drive the display.
>

Substitute BBB with ESP32 to collect the data and serve it over wifi
to other ESPs with tiny OLED displays.
Ok... you will need spectacles. :)
And that will free your BBB for other projects.

Chris Green <cl@isbd.net> wrote:
> I'm not wanting to display a desktop, the display is for use on a boat
> instrument panel to show things like battery voltages, temperatures
> and rudder position.
>
> The above are interesting but the slow refresh is a bit of a nuisance
> as the rudder possition display needs to refresh reasonably frequently.

OK. So you want an LCD, but not the smartphone/tablet/laptop kind. I think
it might be called a 'dot matrix graphic LCD', a bit like on older graphical
calculators. They work with reflected light, rather than generating their
own (although they can have backlights)

The '128x64 graphic LCD' seems to be a common format:
https://www.electronicshub.org/interfacing-128x64-graphical-lcd-with-arduino/
https://thepihut.com/products/128x64-graphic-lcd
(and your favourite internet marketplaces)

- just make sure whatever you get matches the controller supported by the
code.

Theo

Theo <theom+news@chiark.greenend.org.uk> wrote:
> Chris Green <cl@isbd.net> wrote:
>> I'm not wanting to display a desktop, the display is for use on a boat
>> instrument panel to show things like battery voltages, temperatures
>> and rudder position.
>>
>> The above are interesting but the slow refresh is a bit of a nuisance
>> as the rudder possition display needs to refresh reasonably frequently.
>
> OK. So you want an LCD, but not the smartphone/tablet/laptop kind. I think
> it might be called a 'dot matrix graphic LCD',

"Monochrome STN Dot-Matrix LCD" is what I'd call it. Or
alternatively _not_ TFT.

Another option if the text size is a problem might be to use
multiple larger numeric displays.

--
__ __
#_ < |\| |< _#