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Magnethead494
11-16-2012, 05:08 AM
Paul (or somebody that may know),

How many legible lines of text does the 128 x 64 LCD (http://www.pjrc.com/store/dev_display_128x64.html) support? I'm used to the nokia 84x48 display, and I get 6 lines of text out of them, looks to be 8 pixels tall and 5 wide font.

I see in the example code (http://www.pjrc.com/teensy/td_libs_GLCD.html) that there is a 5x7 font- so that would be 8 lines of text, yes?

For one of my projects, deciding between 2-3 nokias or 1-2 of these. Main issues being interface pin count (13 vs 5) and price (30 vs 10). By the looks of it, it would take some code mods to make 2 GLCD's function on a single T++, whereas I can stack as many nokias as I want since the pin defs are done as an int array.

The plan is to have a Fio/xBee module on a backpack/pole with a backfire antenna, then two teensy++'s in the control module- one to interpret controller inputs and send the coded signals to the robot, and one to run the displays, showing current properties of the robot (GPS coords, temperature, speed, and various other data).

https://sphotos-a.xx.fbcdn.net/hphotos-snc6/281440_10151463315089606_447820691_n.jpg

pixelk
11-16-2012, 06:29 AM
The basic font is usually 5x8 pixels, but like on every graphical LCD (even the nokia one) you can define your own font to pack more letters (to the detriment of legibility). I use the adafruit's color lcd 160x128 display which needs fewer pins, has a µSD reader onboard and is 3.3V & 5V compatible.

Magnethead494
11-17-2012, 02:18 AM
Is this (http://www.ladyada.net/learn/lcd/st7565.html) the one you speak of, Pixel?

That's 21 characters x 8 lines, should be enough for what I'll be doing. I like the RGB backlight, will make it easier to see it during the day, but I don't see where that function is control-wise. I don't see any pin bindings, but since it uses the 4050 (same as the nokia) hex buffer, I can probably do it same as the nokia, just tell it the pin array and talk.

edit- saw in the library (http://www.pjrc.com/teensy/td_libs_ST7565.html) that it is indeed a pinmap-array.

Magnethead494
11-17-2012, 02:50 AM
Okay Pixel, now I found the one you speak of. I call that bang-for-buck! $24 for a TFT isn't bad at all.

http://www.adafruit.com/products/358

pixelk
11-17-2012, 09:45 AM
Yup you found it (sorry for the delay). I got both displays, the first one is twice as big, but only monochrome (only the back-light is RGB), they both work perfectly with 3.3V.
The RGB back-light is wired onto 3 different pins, with common cathode (not showed on adafruit's tutorial, they did it with the old 1-color-only version).

The color LCD, while being smalls is perfectly readable with the standard 8x5 font, and the µSD is a great bonus, especially with the teensy 3 (the LCD lib and the SDFat lib take some ROM space).
I'm working on it right now, even at 1/4 brightness it's usable in daylight.

Magnethead494
11-17-2012, 09:53 AM
Yup you found it (sorry for the delay). I got both displays, the first one is twice as big, but only monochrome (only the back-light is RGB), they both work perfectly with 3.3V.
The RGB back-light is wired onto 3 different pins, with common cathode (not showed on adafruit's tutorial, they did it with the old 1-color-only version).

The color LCD, while being smalls is perfectly readable with the standard 8x5 font, and the µSD is a great bonus, especially with the teensy 3 (the LCD lib and the SDFat lib take some ROM space).
I'm working on it right now, even at 1/4 brightness it's usable in daylight.

So the 128x160 1.8 TFT is physically smaller than the 128x64 LCD?

datasheet says 65x88mm for the LCD and 34x56 for the TFT. I guess the TFT lets them cram in more pixel density.

The uSD for me is not an issue, I just want 1 or 2 screens that are easily readable in daylight...and are legible with lots of data on them...

pixelk
11-17-2012, 03:02 PM
Yup, right again.
You can cram much more text in less space with the TFT.
The font is the same on the two displays (sorry for the dust) :

LCD
47

TFT
48

*** EDIT ***
In real life the white text on the TFT has not this red-ish tint.

Magnethead494
11-17-2012, 09:53 PM
Yup, right again.
You can cram much more text in less space with the TFT.

TFT
48

*** EDIT ***
In real life the white text on the TFT has not this red-ish tint.

Welp, that makes my decision right there! I may not even need two displays! 23 characters/16 lines is about what I was targeting!

I'll be reading/displaying, at the very minimum:

GPS Lat
GPS Long
GPS Time
IMU pitch
IMU yaw
IMU roll
IMU/compass heading
Speed
Camera boom height
Potentiometer 1 val, Pot 2 val (same line)
Pot 3 val, Pot 4 val (same line)
Temperature
Batt 1 voltage, Batt 2 voltage (same line)

JBeale
11-17-2012, 10:31 PM
You can certainly display more text with more pixels, but I expect that the larger 65x88mm LCD display should be readable at a glance from a greater distance, if that's important.

Magnethead494
11-17-2012, 10:42 PM
You can certainly display more text with more pixels, but I expect that the larger 65x88mm LCD display should be readable at a glance from a greater distance, if that's important.

It's not. This is going in a robot controller, a-la RC controller, at hand distance. Viewing in glary sun is probably the biggest factor.

JBeale
11-17-2012, 11:14 PM
If you use a 128x64 LCD like this one https://www.adafruit.com/products/250 it is sunlight-readable, because the text is visible even with no backlight. I'm not sure about the TFT, I thought those needed a backlight to work, so if bright sun overpowers the backlight you get very little contrast.

Magnethead494
11-20-2012, 06:30 AM
If you use a 128x64 LCD like this one https://www.adafruit.com/products/250 it is sunlight-readable, because the text is visible even with no backlight. I'm not sure about the TFT, I thought those needed a backlight to work, so if bright sun overpowers the backlight you get very little contrast.

For the size, I like the TFT, though I'm sure you are right, but I've not any experience of TFT's in sunlight.

That said, the one you linked to I wouldn't mind, just a matter of figuring out what backlight color would work good in the daylight.

JBeale
11-20-2012, 03:30 PM
I actually just got the Adafruit 128x64 RGB-backlight LCD, but it might be a while before I get a chance to hook it up and try it out. The carrier PCB makes it slightly too large to fit across the width of the multimeter-style Serpac 4xAA case (http://www.serpac.com/h754AA.aspx) I want to use, but I think I can make it fit after some vicious hacksaw work and minor re-wiring.

JBeale
11-21-2012, 08:03 AM
For what it's worth, you can see the Adafruit 128x64 LCD here in action, showing the kind of refresh rate you might expect. This is my entry for most boring YouTube video ever, but hey, it is available in glorious full-HD. http://www.youtube.com/watch?v=RRorCz6Do5o&feature=youtu.be

Magnethead494
11-21-2012, 08:22 AM
I actually just got the Adafruit 128x64 RGB-backlight LCD, but it might be a while before I get a chance to hook it up and try it out. The carrier PCB makes it slightly too large to fit across the width of the multimeter-style Serpac 4xAA case (http://www.serpac.com/h754AA.aspx) I want to use, but I think I can make it fit after some vicious hacksaw work and minor re-wiring.

See if the SMD pads are 2.54mm or 2mm [looks like 2mm to match the TH spacing] and see if you can get an SMD pinset for it....dremel off the end with the TH connections and it'll fit no problem ;)