7" ssd1963 tft , hr2046 touch and teensy 3.6

Other Hardware Displays
1

Hi ,
I've been looking for a Teensy 3.6 library for a ssd1963 controller for 7" 800x480 display with hr2046 ressistive touch screen.
I used UTFT library for screen, but I want to use a touch screen with it. I tried Utouch and URtouch library too. Both of them working very well with mega2560 an DUE but Touchscreen working very strangely with the Teensy 3.6 boards.
I use the UTFT calibration sketch to run and the touch seems to work, but the results are out of sceen range and completely different values .
What is wrong, Can you help me?

#include <UTFT.h>
#include <URTouch.h>

UTFT myGLCD(SSD1963_800ALT,42,40,52,53);// teensy 36ok
// UTFT(byte model, int RS, int WR,int CS, int RST, int SER)
// #define PORTS USE_B_D_PORTS
// ("DB_0=16, DB_1=17, DB_2=19, DB_3=18, DB_4=0, DB_5=1, DB_6=29, DB_7=30")
// ("DB_8=2, DB_9=14, DB_10=7, DB_11=8, DB_12=6, DB_13=20, DB_14=21, DB_15=5")

// UTouch(byte tclk, byte tcs, byte din, byte dout, byte irq)
//URTouch(byte tclk, byte tcs, byte tdin, byte dout, byte irq);
URTouch myTouch( 13, 10, 11, 12, 24); //tensy3.6

#define TOUCH_ORIENTATION LANDSCAPE

....
...
rest of the URTouch_calibration.ino

teensy3.6_DUE_Touch.jpg
teensy3.6_DUE_Touch.jpg1599×899 279 KB

teensy3.6_DUE_Touch.jpg
teensy3.6_DUE_Touch.jpg1599×899 279 KB

2

It looks as if Teensy3 comes with an ancient UTFT v2.72 that has been hacked for Teensy. (UTFT is currently v2.83)

Since the SSD1963 board has 3.3V signals you can either wire directly to the Teensy3.6 or via the Mega2560 Adapter shield.

Either way, it is a lot of GPIO pins to find on the Teensy3.6

When you have the display working, you need to route more wires for the HR2046 / XPT2046 Touch Controller chip.
You can either bit-bash on GPIO pins with URTouch.h in Henning Karlsen fashion.
Or you use HW SPI pins with XPT2046_TouchScreen.h in intelligent Paul Stoffregen fashion.

Personally, I would configure SSD1963 for 8080-8 interface and connect the xx2046 chip to SPI pins.
It is pretty simple to create an 8-bit Parallel driver. It is just as fast and you don't lose so many GPIO pins.

David.

3

How often is your teensy 3.6 working? The URtouch library does not behave well after 180 MHz, between 120 and 180 it responds well.

4

Hi David and TFTLCDCyg,
Thank you for your help and suggestions.
I tried all the CPU frequencies, but it's still not working.
I once again tried using Stoffregen and Karlsen's libraries with all CPU frequencies but touch part still did not work normally with T36.
I've tried using Arduino DUE with URTouch Library instead, and it worked. (Both the screen and the touchpad worked very well and coordinates are true ( so TFT and Touch hardware is OK)

Additionally, I tried for XPT2046_Calibrate ( with corrected for ssd1963 parallel TFT ), Calibration.ino and DrawWithCalibration.ino in XPT2046_Touchscreen-master library. (ardnew/XPT2046_Calibrated , forked from PaulStoffregen/XPT2046_Touchscreen)
But touch part didnt work normally stilll with T36, the touch seems to work, but the results are out of screen range and completely different values .
I dont want to use DUE , its not fast enough . Thank you for your help again but I'm still trying.
My best wishes for 2021.

5

The Due is very fast. Most importantly, there are 40-pin Adapter Shields for the Due. So everything plugs together nicely.

Think about it. URTouch bit-bangs random GPIO pins. The XPT2046 / HR2046 is an SPI device with maximum 2.5MHz SCK frequency.
A 16MHz Mega2560 can never achieve 2.5MHz with digitalWrite() or even with direct Port addressing. However an 180MHz Teensy3.6 is a lot faster. Add some delays to URTouch library's bit-banging and the Teensy should work.

Alternatively you use HW SPI as Nature intended. XPT2046_TouchScreen should use SPI at an appropriate speed.

David.