Showdog LCD Board Feedback

TinCanTools is looking for some feedback on the features to be included with the Showdog LCD board. current features include:

480x272 TFT lcd(not the PSP display)
4-wire Touchscreen(via TSC2007)
3 mircoswitch buttons
2 RGB leds
analog thumb joystick
analog slider

suggestions/feedback as well as pros/cons of the config would be appreciated

Dave

Will it have a fixed backlight or a variable intensity version?

What about a reset button?

Gerald

Gerald,

Will it have a fixed backlight or a
variable intensity version?

the backlight will be controlled via one of the PWM lines. the two RGB LEDS would be controlled via PWM as well.

What about a reset button?

i had not considered a reset button since the beagle had one on it already. adding one accessable from the from would be preferable?

Dave

Perfect on the backlight!!

The reset depends on the mounting of the LCD. I assume this will have the Beagle plugged into the back of your board. To do a reset, the user would need to flip the whole thing over. As this is being used for development, if the reset switch is thought to be used often, and I would leave that to others to comment on, then it would be good to have it. If not, then I would not put it on.

Gerald

Gerald,

Perfect on the backlight!!

The reset depends on the mounting of the LCD. I assume
this will have the Beagle plugged into the back of your
board. To do a reset, the user would need to flip the whole
thing over. As this is being used for development, if the
reset switch is thought to be used often, and I would leave
that to others to comment on, then it would be good to have
it. If not, then I would not put it on.

i can follow that. if i am going to add a reset button on the from, what about a power switch on the front as well? have a barrel connector on the showdog and feed the +5v via expansion header?

i think the main question i have about the features is, does everyone want a plain jane lcd board with nothing but the lcd, or are they interested in the input methods like the analog joystick and buttons?

Dave

Without a cable plugged into the Beagle barrel jack, the USB OTG power is routed to the intenral bus. If you ever plug in an OTG cable, puff the rmagic dragon will appear.

If you designed the full up, could you offer a cutdown version with just plain Jane?

Gerald

Gerald,

Without a cable plugged into the Beagle
barrel jack, the USB OTG power is routed to the intenral
bus. If you ever plug in an OTG cable, puff the rmagic
dragon will appear.

ahh right i always forget about the OTG power since i _never_ power my boards that way.

If you designed the full up, could you offer a cutdown
version with just plain Jane?

yea there isn't a reason you couldn't just have NOPOPs for the the input methods, main concern is spending the time and resources to design it with those inputs if no one will want them.

there are half a dozen various input methods that might be interesting to have:

thoughts?

Dave

I have used the item on the second link before. They weren’t all that rugged. The other ones look OK, although, I am not sure what the use case would be for the slide switch.

Also, on the power feeding from the the LCD board, I am looking to add a feature on the new beagle to allow this to happen by being able to ground a pin and prevent the switch from turning on that provides power to the board from the OTG. Let’s sync up on that in a few weeks on how that is done.

Gerald

Gerald,

I have used the item on the second
link before. They weren't all that rugged. The other
ones look OK, although, I am not sure what the use case
would be for the slide switch.

i wasnt impressed with item #2 as well, but i wanted to throw out some options. the slide seems to be a popular item with arduino/avr crowd for controlling various mechanical experiments.

Also, on the power feeding from the the LCD board, I
am looking to add a feature on the new beagle to allow this
to happen by being able to ground a pin and prevent the
switch from turning on that provides power to the board from
the OTG. Let's sync up on that in a few weeks on how
that is done.

sounds like a plan, i'll keep an ear out for things.

dave

I still think for something as powerfull as an OMAP3 WVGA more appropriate, but I can see how that would be more $$$$

regards,

Koen

David Anders wrote:

TinCanTools is looking for some feedback on the features to be included with the Showdog LCD board. current features include:

480x272 TFT lcd(not the PSP display)

800x480? :slight_smile:

Koen,

the problem i am faced with for the wvga is the cost difference. in the quantity we are talking about for the ShowDog, using the wvga would make the showdog $50 to $75 more. beagleboard developers are generally pretty price conscience so i'm concerned that everyone will say "that looks great, it has exactly what i want, but it is too expensive"

dave

Koen,

the problem i am faced with for the wvga is the cost difference. in the quantity we are talking about for the ShowDog, using the wvga would make the showdog $50 to $75 more. beagleboard developers are generally pretty price conscience so i'm concerned that everyone will say "that looks great, it has exactly what i want, but it is too expensive"

That's what I feared :frowning:

regards,

Koen

LCDs are hard to find, especially if you want a good price and a steady supply!

Gerald

LCDs are easy to find.

Finding the same one a day later can be really hard.

It seems like commodity consumer electronics have a half life measured in hours.

Good, bad or indifferent, the PSP screen has many sources.

- dan

That was my point exactly. NEC and Sharp can have good supply record, especially NEC, but they are a little more expensive.

Gerald

We are on the same side of the table for sure...

Another huge impediment to progress is the software to customize a
driver for a particular panel.

The last time I looked at an LCD the timing for two physically and
electrically identical parts from two different vendors was actually
different! How do you deal with that?

The other big dog in the LCD yard is the iPod/iPhone/iTouch... 480x320
@ 163 dpi, not too shabby...

You would have to pick '2G' vs '3G' but once you did, abundant supply!

- dan

Daniel,

LCDs are easy to find.

Finding the same one a day later can be really hard.

i have a working relationship with a number of lcd suppliers and have found a really nice 480x272 tft similar to the PSP display.

Good, bad or indifferent, the PSP screen has many sources.

the one i've selected has a couple of major advantages over the PSP

* only requires +3.3v power supply for logic
* uses a single connector for touchscreen, backlight, and lcd data

this makes the overall design of the board much much easier.

any thoughts on the input methods for the board?

Dave

Hey Dave,

The PSP panel is all kinds of trouble with regards to power. I imagine
that is why it never really caught on with us Beagleboarders...

Your input sources look to be very complete! I see this board as a big
opportunity in the HMI prototype space. 'Try before you fly...'

To me, reprogrammable soft buttons are a big win over the touchscreen.
Four would be nice with lots of configurations that come to mind,
'North, South, East, West', ATM-like column to the side of the screen,
inverted 'T' cursor, in a row across below the screen, etc...

The analog thumb joystick begs for a pair of 'mouse' buttons as well...

I am with Gerald on the slider, but if there is interest, go for it!

hi,
I am looking at using 8.9", 10.1", 11.6" lvds screens.

anyone interested?

KP