Will a UNO R3 2.8" TFT touch screen with SC card socket work with the Raspberry Pi 2 B?
Will a UNO R3 2.8" TFT touch screen with SC card socket work with the Raspberry Pi 2 B?
Hi Shay,
I also received this notification from Amazon in Spain. I checked the users review before buying and I found this that made me suspiciuous:
These are FAKE. They are unsuitable for an Arduino as they have a 16-bit interface while the Arduino only has an 8-bit, therefore they cannot be made to work. The screens have been mounted on an 8-bit board which connects directly to the top of the Arduino Uno, so at first glance it appears they should work, don't be deceived!
This is an example of very poor and unethical construction. Taking an item and mounting it to a PCB that you know will prevent it from working and then marketing it as something which it is not.
This comes with no documentation, and after extensive research and experimentation, blood, sweat and tears etc you discover that you've been ripped off as it inherently CAN'T work no matter what you try. Sure you can get some limited functionality, colours displaying incorrectly, draw basic shapes etc, but you can't display characters or graphics as you should and therefore it is useless as a component for a project.
The trouble with sending 8-bit code to a 16-bit device is that you can only address the first 8-bits of the screen, so anything that requires bits 9-16 to be addressed remains forever unuseable.
The only hope if that in some way, despite the 16 bit addresses there is also an alternative way to make it working in an 8 bit environment. If you enlarge the only one image of the device back side, you see the following (with some small image enhancement):
Only can confirm to us for sure but these PINs seems LCD RST, CS, SS, WR, RD so maybe there is a way to drive the LCD in a different way than 16 bit pin addresses. One try to be checked - if the speed is sufficient - is with a couple of shift registers daisy-chained, but I am not sure if the frequency response of the shift registers is sufficient. If it is, it is one of the solutions using very few pins on both the Arduino and Raspberry PI. About the shift registers you can take a look to the following link: https://www.tindie.com/products/alicemirror/daisy-chained-shift-registers-board-arduino-kit/
Another Amazon reviewer instead wrote:
I bought this screen as a gift for a friend who wants to get into embedded programming. After reading some of the reviews which say the supplied drivers aren't very good; I decided I would have a go at making it work before handing it over.
I did manage to get it to work, the steps I followed are shown below.
As for the review, this is a nice little unit, It is will made considering the price and it gives you a whole bunch more things you can do with your Arduino. I would definitely recommend this unit. I knocked a star off because the whole point of Arduino is that its meant to be easy, and as you will see, getting this working wasn't straight forward to figure out (although the steps are pretty easy to follow).
Here is how I got it working:
1: Download the zip file from this URL: http://ftp2.linkdelight.com/P0008904.zip
2: Unzip it and open it. Inside is another zip file called arduino-UNO2.4 (with some extra characters on the end) unzip that
3: open it up, you will find a full copy of the (old) Arduino IDE with lots of different LCD libraries installed. Go into the library folder and copy the "TFTLCD" and "touch screen library" folders into the libraries folder of your current Arduino IDE sketches folder (find the location of this funder under file->preferences within the IDE)
4: Rename the touch screen library folder so there are no spaces in the name
5: Open TFTLCD.cpp and replace line 76 with: size_t TFTLCD::write(uint8_t c) {
6: In the same file on line 85 you will see a } character, add a new line below this and add: return(1);
7: Save and close TFTLCD.cpp and open TFTLCD.h. In this file replace line 95 with: virtual size_t write(uint8_t);
8: At the top of this file replace "#include <WProgram.h>" with:
#if ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
9: Save and close TFTLCD.h and open the Arduino IDE
10: go to File->examples->TFTLCD->tftpaint and open the example
11: At the top of the file you will see some defines which set which pins the touch screen is connected to, they are wrong! change them to the following:
#define YP A1 // must be an analog pin, use "An" notation!
#define XM A2 // must be an analog pin, use "An" notation!
#define YM 7 // can be a digital pin
#define XP 6 // can be a digital pin
12: Compile and upload the code, you should get a sort of digital white board with different coloured pens to use.
After this you should be able to save a copy of that example code and start experimenting with the graphics drawing primitive functions and actually build a user interface or what ever your project is.
As you have the stuff in your hands, maybe it is the worth to try following these instructions the probably it is possible to make a decision that has sense.
Enrico
