7" LCD Touch

Other Hardware Displays
1

Hello everyone,

I want to buy a 7" inch touch display for my project with an Arduino Mega, Ethernet shield and EasyVR shield.

I found this 7 inch LCD Module w/Optional Capacitive Touch Screen Panel,I2C/SPI that I understand works with Arduino and seens at a good price with the RA8875 driver.

I have doubts about the options I have to buy it, mainly about the capacitive touch x resistive touch.
But with everything else too, including the:

Interface: Pin Header Connection Parallel, I2C, 3 Wire SPI, 4 Wire SPI or the FFC? I read some where in the forum people using the 4 Wire SPI, that is the easiest to use? Which would be faster? I will be mostly showing of weather informations, using it as a alarm clock, and with some "floor blueprints" that can be done with simple squares buttons. So, probably not loading alot of images, just a sun, a moon, a cloud, to illustrate the weather. The response will be badly? I saw some people saying about 1 minute to load up some images.

Power Supply: I think should be 5V since I will power it from the Arduino, right?.

Font Chip: I don't know the diference between them ER3300-1 / ER3301-1 / ER3303-1 / ER3304-1.

Can I have some advice please???

As I said, mostly about the capacitive x resistive touch, which is better documented? Which is easier to use?

I'm not a newbie, but still learning on the fly, already did some cool things, but in eletronics I stil don't get a lot of things, I just want to make sure to buy the correct product, I do accept indications of better products too, I saw the Sainsmart ones, that is a bit more pricey, but not out of my range.

2

Arank:
I have doubts about the options I have to buy it, mainly about the capacitive touch x resistive touch.
But with everything else too, including the:

Interface: Pin Header Connection Parallel, I2C, 3 Wire SPI, 4 Wire SPI or the FFC? I read some where in the forum people using the 4 Wire SPI, that is the easiest to use? Which would be faster? I will be mostly showing of weather informations, using it as a alarm clock, and with some "floor blueprints" that can be done with simple squares buttons. So, probably not loading alot of images, just a sun, a moon, a cloud, to illustrate the weather. The response will be badly? I saw some people saying about 1 minute to load up some images.

I2C and SPI would be the fastest, but all this depends on your code. From what you are wanting, the code will be long and of course that takes cpu cycles. It all comes down to efficiency.

Power Supply: I think should be 5V since I will power it from the Arduino, right?

Yes, this LCD can be powered off of 5V, but not from the Arduino. You would need a separate supply to provide the 300mA that it needs.

Font Chip: I don't know the diference between them ER3300-1 / ER3301-1 / ER3303-1 / ER3304-1./

You could use Google to look these up and compare them yourself.

Can I have some advice please???

As I said, mostly about the capacitive x resistive touch, which is better documented? Which is easier to use?

I'm not a newbie, but still learning on the fly, already did some cool things, but in eletronics I stil don't get a lot of things, I just want to make sure to buy the correct product, I do accept indications of better products too, I saw the Sainsmart ones, that is a bit more pricey, but not out of my range.

My advice would be to buy from somewhere that stand by their products and have tested them. Sainsmart is a good place as they provide support. Other places like Adafruit and Sparkfun have displays and also comes with tutorials and Arduino libraries.

3

codlink:
I2C and SPI would be the fastest, but all this depends on your code. From what you are wanting, the code will be long and of course that takes cpu cycles. It all comes down to efficiency.

My advice would be to buy from somewhere that stand by their products and have tested them. Sainsmart is a good place as they provide support. Other places like Adafruit and Sparkfun have displays and also comes with tutorials and Arduino libraries.

Thanks for your input, by SPI you mean the 4 Wire SPI? And can you indicate which one should I look for on Sainsmart, Adafruit, or Sparkfun? As I said, I'm not an eletronic's guy, it all looks the same to me...

4

You can get other the capacitive touch or resistive touch, there are libraries for both.

For the Ra8875... You'll need to isolate the spi lines from anything else using spi.....

4wire spi is the only interface that has libraries, so unless you plan on writing a library yourself...

Keep in mind that loading images from an SD card will be a very slow business (>17sec)

5

Qdeathstar:
You can get other the capacitive touch or resistive touch, there are libraries for both.

GitHub - sumotoy/RA8875: A library for RAiO RA8875 display driver for Teensy3.x or LC/Arduino's/Energia/Spark

For the Ra8875... You'll need to isolate the spi lines from anything else using spi.....

4wire spi is the only interface that has libraries, so unless you plan on writing a library yourself...

Keep in mind that loading images from an SD card will be a very slow business (>17sec)

Thanks for the info, which one you think may be better? By looking the examples of the library you provided it seens to me that the resistive are easier and uses less coding, is that right?

What do you mean by isolate the SPI lines? I think the Ethernet Shield uses it too, right? So both will be incompatible in the same project??

And about the images, even small images (120x120) take all that long?

6

120x120 will be faster. You can use spi for both the Ethernet shield and the ra8875, but you have to have to isolate the spi lines because ra8875 doesn't tristate the miso line, and there is another bug aswell, the wiki for that library has the info

7

Qdeathstar:
Keep in mind that loading images from an SD card will be a very slow business (>17sec)

I wonder where you people get your misinformation? Granted the Mega is pretty rubbish compared to the DUE but even the Mega can load a 800x480 from SD in around 6 seconds, compared to about 800ms on a DUE....

codlink:
My advice would be to buy from somewhere that stand by their products and have tested them. Sainsmart is a good place as they provide support. Other places like Adafruit and Sparkfun have displays and also comes with tutorials and Arduino libraries.

I was in agreement right up until recommending Sainshit............. You saw how many posts are on this forum from users that had the misfortune of buying from them???????????????? They are a company of ill-repute, cloning from more reputable manufacturers, supplying software they don't have permission to supply and personally, I can say the quality control of some of their products is questionable..... My recommendation for what it is worth............... AVOID Saincrap!!!!! Pay $3-$5 more and buy from ANYWHERE else..........

Regards,

Graham

8

ghlawrence2000:
I wonder where you people get your misinformation? Granted the Mega is pretty rubbish compared to the DUE but even the Mega can load a 800x480 from SD in around 6 seconds, compared to about 800ms on a DUE....

I was in agreement right up until recommending Sainshit............. You saw how many posts are on this forum from users that had the misfortune of buying from them???????????????? They are a company of ill-repute, cloning from more reputable manufacturers, supplying software they don't have permission to supply and personally, I can say the quality control of some of their products is questionable..... My recommendation for what it is worth............... AVOID Saincrap!!!!! Pay $3-$5 more and buy from ANYWHERE else..........

Regards,

Graham

Thanks Graham, indeed I saw alot of complaints about Sainsmart Displays here on the forum, so I just passed on they screens. I'm pending between the Chinese (I mentioned on the first post), and this one Display Module - 7" Touchscreen LCD from Sparkfun / 4D, that I saw it's really easy to connect, to program and even have a forum on they on. The only problem is the price, it's 5 times more expensive then the chinese one, I don't know if it's worth...

It actually brings up another question, for the Sparkfun display, I saw the software to upload the screens layout to the display (I even downloaded it to check it out). But if I go for the Chinese how should I do that?

9

Hi Arank,

I agree $180 is a bit much....

Have you heard of Nextion from iTead studios? That may be another option.

I just did some googling......... A forum contact of mine sent me a message the other day showing some work he is doing with a 4D systems FT843..... let me show you his demo....... FT843 + GD2 + Due: Iconos en movimiento - YouTube That looks worth it to me :stuck_out_tongue:

I don't personally have any experience of the RA8875 controller, but I understand it has several nice features.

It would heavily depend on what your target application is aiming to achieve as to which display would best suit your purposes. Let me give you just a few pointers.......... Don't buy from Saincrap.......... Avoid Sainshit......... Did I mention Sainsmart are not great?

No, seriously!! The Mega is brilliant at what it does, but if you buy a DUE after you buy a MEGA, you will wish you got the DUE sooner, and your Mega will start gathering dust............. the difference is THAT dramatic! If you are tempted to go down the SPI display route, you DEFINITELY want a DUE, not a Mega! Simple reason being, the SPI speed of the Mega is 4Mhz? You can squeeze 42Mhz out of the DUE SPI, AND you can drive it via DMA, the Mega has no DMA.

If you INSIST on going down the Mega route, it would be advantageous to get an intelligent display just to make up for inadequacies of the Mega, some of these are overcome when using the Due, so a dumb display is less of a performance hit.

Is 7" one of your Mandatory design choices? The reason I ask is that the youtube video of the 4D systems display you saw was a 4.3" device and you can get those for about $50....

The 7" Nextion is about $75.... https://www.itead.cc/display/nextion.html?display_size=747

If you want ease of programming and massive support base, you should stick to the standard UTFT supported devices.

This might give you a bit more to think about.

Regards,

Graham

10

ghlawrence2000:
Have you heard of Nextion from iTead studios? That may be another option.

I already heard of ITEAD, not about this Nextion.. It seens it leaves alot of the processing for the Arduino, I don't know if I'm ready to do it all...

ghlawrence2000:
I just did some googling......... A forum contact of mine sent me a message the other day showing some work he is doing with a 4D systems FT843..... let me show you his demo....... https://www.youtube.com/watch?v=45auLwBeFCs That looks worth it to me :stuck_out_tongue:

It seens pretty cool, as I see it, he did that using the DUE for everything? Since that LCD doesn't have a driver attached? Or he attached a RA 8875?

ghlawrence2000:
No, seriously!! The Mega is brilliant at what it does, but if you buy a DUE after you buy a MEGA, you will wish you got the DUE sooner, and your Mega will start gathering dust............. the difference is THAT dramatic! If you are tempted to go down the SPI display route, you DEFINITELY want a DUE, not a Mega! Simple reason being, the SPI speed of the Mega is 4Mhz? You can squeeze 42Mhz out of the DUE SPI, AND you can drive it via DMA, the Mega has no DMA.

If you INSIST on going down the Mega route, it would be advantageous to get an intelligent display just to make up for inadequacies of the Mega, some of these are overcome when using the Due, so a dumb display is less of a performance hit.

I was thinking exactly about it, my biggest doubt is, the MEGA code can be ported to the DUE? I think I already seen some people complain about isn't. It's hard to port it out? Using that Sparkfun 4D with a DUE would be better or it's killing a ant with a bazooka kinda thing?

ghlawrence2000:
Is 7" one of your Mandatory design choices? The reason I ask is that the youtube video of the 4D systems display you saw was a 4.3" device and you can get those for about $50....

If you want ease of programming and massive support base, you should stick to the standard UTFT supported devices.

Isn't exactly mandatory, but I would like to have a big screen, I plan to hang it on the wall right on my bed, to use as an alarm clock / weather checking station, and as I already use, with voice recognition and as a webserver to control my house automation (ligths, TV's, HT's, etc.).

The inteligent 4.3" display goes for US$ 150,00 so no big difference, but that "dumb" one from the video, is really cheap. How your friend managed to control it?

And about the standard UTFT devices, I didn't find any 7" inch, and the processing is left all for the Arduino right? I don't know if I'm ready to the task, the screens I want to make are not that hard if it's done graphically, but it's alot harder if done by coding, my HTML code as almost 250 lines for it...

11

I think we have a communication breakdown somewhere? The FT843 IS an intelligent device.... and you are wrong by a factor of 2 on price! http://www.ftdichip.com/Products/Modules/4D.html

It depends how old the information you are referring to about compatiblity between Mega and DUE code is........... There might be the ODD library here or there, but nowdays I can load any sketch I have without many changes and it works on both...... For example UTFT initialiser on MEGA UTFT myGLCD(CTE50,38,39,40,41); equivalent for DUE UTFT myGLCD(CTE50,25,26,27,28); thats it, all display functions provided by UTFT are the same.... The biggest difference is the Mega is 5V device and the DUE is a 3.3V device........... since most displays are 3.3V devices it makes life easier....

Examples of 7" displays which work with UTFT.
http://www.ebay.com/itm/7-7-0-inch-TFT-LCD-module-CPLD-SDRAM-800x480-arduino-DUE-MEGA2560-MS070SD-/121186426608?hash=item1c37461ef0
http://www.ebay.com/itm/7-7-0-inch-TFT-LCD-module-Font-IC-800x480-SSD1963-arduino-DUE-MEGA2560-3-5-4-3-/111008432389?hash=item19d89e4105

Those items are from Coldtears, and are guaranteed to work flawlessly with UTFT, also they are what Saincrap sell clones of which have assorted mirror/flip/rotation issues aswell as mirrored/flipped touch function.....

If you are not doing high speed animation or fancy transparent stuff as you saw in the youtube video, one of the above will do you fine........... Incidentally, the CPLD model mentioned has 8 pages of buffer memory, allowing 8 different screens to be held at once, and switched between instantly after the initial rendering.......... this is what is possible with a Mega and CPLD display, the videos are from an incomplete project I did a year ago........ Vivarium10Jan2015 - YouTube

The easiest way to do it, is design your screens in 'Phtoshp' and load them as images.............. writing only text when a parameter is changed, thats how the vivarium was done...

Hope this helps.

Graham

12

ghlawrence2000:
I think we have a communication breakdown somewhere? The FT843 IS an intelligent device.... and you are wrong by a factor of 2 on price! http://www.ftdichip.com/Products/Modules/4D.html

It depends how old the information you are referring to about compatiblity between Mega and DUE code is........... There might be the ODD library here or there, but nowdays I can load any sketch I have without many changes and it works on both...... For example UTFT initialiser on MEGA

UTFT myGLCD(CTE50,38,39,40,41);

equivalent for DUE

UTFT myGLCD(CTE50,25,26,27,28);

thats it, all display functions provided by UTFT are the same.... The biggest difference is the Mega is 5V device and the DUE is a 3.3V device........... since most displays are 3.3V devices it makes life easier....

Examples of 7" displays which work with UTFT.
http://www.ebay.com/itm/7-7-0-inch-TFT-LCD-module-CPLD-SDRAM-800x480-arduino-DUE-MEGA2560-MS070SD-/121186426608?hash=item1c37461ef0
http://www.ebay.com/itm/7-7-0-inch-TFT-LCD-module-Font-IC-800x480-SSD1963-arduino-DUE-MEGA2560-3-5-4-3-/111008432389?hash=item19d89e4105

Those items are from Coldtears, and are guaranteed to work flawlessly with UTFT, also they are what Saincrap sell clones of which have assorted mirror/flip/rotation issues aswell as mirrored/flipped touch function.....

If you are not doing high speed animation or fancy transparent stuff as you saw in the youtube video, one of the above will do you fine........... Incidentally, the CPLD model mentioned has 8 pages of buffer memory, allowing 8 different screens to be held at once, and switched between instantly after the initial rendering.......... this is what is possible with a Mega and CPLD display, the videos are from an incomplete project I did a year ago........ https://www.youtube.com/watch?v=3xLL2iBR4_c&list=PLr-hMPOfKXXZeir5kvi2WoYi9ISMFVkbs

The easiest way to do it, is design your screens in 'Phtoshp' and load them as images.............. writing only text when a parameter is changed, thats how the vivarium was done...

Hope this helps.

Graham

Ahhhhhhhhhhhh, so many options, everything look so identical...
I will think / study more about it, I still have 1 week until my trip to US, so no rush in deciding. If I go for the uLCD-70DT with a DUE, aside from the price there is no error? It's a good choice? I think this will be much easier to program, and I'm just not confident enough to risky expending money in something harder that will maybe be throw aside if I can't manage to work...

For what I want to do, I can't use images for the backgrounds, because I will do some red buttons to ilustrate the lights off, that when I click I would want to turn green, and there is like 10-15 buttons on each page (total 3 pages for that, 1 for each floor) so I can't make images for all the possible combinations of on/off ligths. For what I saw about the VISI GENIE software and library, it seens pretty straight forward, and does not involve much complex coding.

13

I am not familiar with that hardware, maybe somebody else can chip in?

Good luck with your project.

Regards,

Graham

14

ghlawrence2000:
I wonder where you people get your misinformation? Granted the Mega is pretty rubbish compared to the DUE but even the Mega can load a 800x480 from SD in around 6 seconds, compared to about 800ms on a DUE....

Graham

He was asking about an ra8875. Not any display. You have to transfer images from an sd card pixel by pixel over the ra8875. It does indeed take about 17sec with an ra8875. I was using a teensy at 48mhz...

15

I am surprised at that...... Granted I have no experience of the RA8875 but I thought it was supposed to be quite good.... makes me pleased I went with the SSD1963 option when I recently purchased a large display.

Regards,

Graham

16

I have no idea what Qdeathstar has been up to.

The RA8875 can control an SD card natively.

Typing from memory. As far as I can remember, the RA8875 handles many graphics primitives.

David.

17

Does somebody know where can I found i2c library for RA8875 TFT DISPLAY ?