1.8" TFT LCD w/joystick and SD card. white screen

[asteroide06]

Hello,

I just received an Adafruit shield, Adafruit 1.8" 18-bit Color TFT Shield w/microSD and Joystick, ID 802.
I connect it on an Arduino Mega 2560. As many other users, when upload any of the exanples provided with ADAFRUIT8ST7732 library examples, the screen is always white. The serial monitor shows a normal behavior. I can read the messages, the values of the analog reading with the joystick, etc... I changed the CS value to 10 and DC value to 8, according to the pin numbering on the shield. I double checked the solderings, redid them to make sure they make a good contact. No change.
You can see pictures of the solderings here:
http://www.asteroide06.fr/soldering1.jpg
http://www.asteroide06.fr/soldering2.jpg
They are not perfect (done with a smartphone)

What else can I try ?

Thanks for your help

[asteroide06]

Ok, I got the solution. In the examples provided, the sclk and mosi pins must be used too. I first changed only the CS, DC and RST adresses. It's not enough to make it fully functional on an Arduino mega 2560.

For example in graphicstest, the original code is:

Code: Select all

#define sclk 4
#define mosi 5
#define cs   6
#define dc   7
#define rst  8  // you can also connect this to the Arduino reset

To make it work with Arduino mega 2560:

Code: Select all

#define sclk 13
#define mosi 11
#define cs  10
#define dc   8
#define rst -1  // you can also connect this to the Arduino reset

In shieldtest, the original code is:

Code: Select all

#define SD_CS    4  // Chip select line for SD card
#define TFT_CS  10  // Chip select line for TFT display
#define TFT_DC   8  // Data/command line for TFT
#define TFT_RST  -1  // Reset line for TFT (or connect to +5V)
Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, TFT_RST);

To make it work with Arduino mega 2560:

Code: Select all

#define sclk 13
#define mosi 11
#define SD_CS    4  // Chip select line for SD card
#define TFT_CS  10  // Chip select line for TFT display
#define TFT_DC   8  // Data/command line for TFT
#define TFT_RST  -1  // Reset line for TFT (or connect to +5V)
Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, mosi, sclk, TFT_RST);

Hope this helps.

[dmpyron]

Thanks for doing my research! Now I won't wander around trying to figure what little thing I've done wrong.

[unexpectedly]

Thank you so much! I've already burned a diagonal black line in my screen from trying to figure this out.

Adafruit, please put something somewhere in the description about Mega people seeing this thread.

Yaaay, now I can get back to trying to use this to control my test bench... AND get a graph readout!

Thanks,
Chris

[unexpectedly]

Whoops, was happy too soon. Graphics test works from changes above but not shield test. I'll figure it out...

[peony3000]

Hi
I'm was getting the white screen with a Arduino Uno
The correct pin assignments are....

Code: Select all

// You can use any (4 or) 5 pins
#define sclk 13
#define mosi 11
#define cs   10
#define dc   8
#define rst  -1  // you can also connect this to the Arduino reset

Andy

[adafruit_support_mike]

This is an issue we started seeing with a small number of TFT shields after pburgess, our blinky-stuff guru, optimized the library. Unfortunately, it hits so rarely that he hasn't been able to replicate the issue and fix it.

Try using this version of the library: https://github.com/adafruit/TFTLCD-Libr ... 5263787d1f

[unexpectedly]

BTW, to update, I was able to get it working to the point where a joystick move could make words show up on the screen. I forgot exactly what I did, but I recall it was an issue of getting all the pin #s right on my Mega. If someone comes here via google with a Mega and is stuck ,reply and I'll dig up the sketch.