For anyone who wants to use the 3.5 inch touch shield of adafruit. It took me quite some time to find the right setup, because the HX8357 libraries dont work well on teensy.
Here example of my configuration (build on max 168mhz):
/***************************************************
This is our touchscreen painting example for the Adafruit ILI9341 Breakout
---->
http://www.adafruit.com/products/2050
Check out the links above for our tutorials and wiring diagrams
These displays use SPI to communicate, 4 or 5 pins are required to
interface (RST is optional)
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
Written by Limor Fried/Ladyada for Adafruit Industries.
MIT license, all text above must be included in any redistribution
****************************************************/
/** NOT FOR USE WITH THE TOUCH SHIELD, ONLY FOR THE 3.5" BREAKOUT! **/
//#include <Adafruit_GFX.h> // Core graphics library
#include <SPI.h>
#include "ILI9341_t3.h"
#include "TouchScreen.h"
// These are the four touchscreen analog pins
#define YP A2 // must be an analog pin, use "An" notation!
#define XM A3 // must be an analog pin, use "An" notation!
#define YM 7 // can be a digital pin
#define XP 8 // can be a digital pin
// This is calibration data for the raw touch data to the screen coordinates
#define TS_MINX 110
#define TS_MINY 80
#define TS_MAXX 900
#define TS_MAXY 940
#define MINPRESSURE 10
#define MAXPRESSURE 1000
// For the Adafruit shield, these are the default.
#define TFT_DC 9
#define TFT_CS 10
// Use hardware SPI (on Uno, #13, #12, #11) and the above for CS/DC
ILI9341_t3 tft = ILI9341_t3(TFT_CS, TFT_DC);
// For better pressure precision, we need to know the resistance
// between X+ and X- Use any multimeter to read it
// For the one we're using, its 300 ohms across the X plate
TouchScreen ts = TouchScreen(XP, YP, XM, YM, 300);
// Size of the color selection boxes and the paintbrush size
#define BOXSIZE 40
#define PENRADIUS 3
int oldcolor, currentcolor;
void setup(void) {
while (!Serial); // used for leonardo debugging
Serial.begin(115200);
Serial.println(F("Touch Paint!"));
tft.begin();
tft.fillScreen(ILI9341_BLACK);
// make the color selection boxes
tft.fillRect(0, 0, BOXSIZE, BOXSIZE, ILI9341_RED);
tft.fillRect(BOXSIZE, 0, BOXSIZE, BOXSIZE, ILI9341_YELLOW);
tft.fillRect(BOXSIZE*2, 0, BOXSIZE, BOXSIZE, ILI9341_GREEN);
tft.fillRect(BOXSIZE*3, 0, BOXSIZE, BOXSIZE, ILI9341_CYAN);
tft.fillRect(BOXSIZE*4, 0, BOXSIZE, BOXSIZE, ILI9341_BLUE);
tft.fillRect(BOXSIZE*5, 0, BOXSIZE, BOXSIZE, ILI9341_MAGENTA);
tft.fillRect(BOXSIZE*6, 0, BOXSIZE, BOXSIZE, ILI9341_BLACK);
tft.fillRect(BOXSIZE*6, 0, BOXSIZE, BOXSIZE, ILI9341_WHITE);
// select the current color 'red'
tft.drawRect(0, 0, BOXSIZE, BOXSIZE, ILI9341_WHITE);
currentcolor = ILI9341_RED;
}
void loop()
{
// Retrieve a point
TSPoint p = ts.getPoint();
// we have some minimum pressure we consider 'valid'
// pressure of 0 means no pressing!
if (p.z < MINPRESSURE || p.z > MAXPRESSURE) {
return;
}
Serial.print("X = "); Serial.print(p.x);
Serial.print("\tY = "); Serial.print(p.y);
Serial.print("\tPressure = "); Serial.println(p.z);
// Scale from ~0->1000 to tft.width using the calibration #'s
p.x = map(p.x, TS_MINX, TS_MAXX, 0, tft.width());
p.y = map(p.y, TS_MINY, TS_MAXY, 0, tft.height());
/*
Serial.print("("); Serial.print(p.x);
Serial.print(", "); Serial.print(p.y);
Serial.println(")");
*/
if (p.y < BOXSIZE) {
oldcolor = currentcolor;
if (p.x < BOXSIZE) {
currentcolor = ILI9341_RED;
tft.drawRect(0, 0, BOXSIZE, BOXSIZE, ILI9341_WHITE);
} else if (p.x < BOXSIZE*2) {
currentcolor = ILI9341_YELLOW;
tft.drawRect(BOXSIZE, 0, BOXSIZE, BOXSIZE, ILI9341_WHITE);
} else if (p.x < BOXSIZE*3) {
currentcolor = ILI9341_GREEN;
tft.drawRect(BOXSIZE*2, 0, BOXSIZE, BOXSIZE, ILI9341_WHITE);
} else if (p.x < BOXSIZE*4) {
currentcolor = ILI9341_CYAN;
tft.drawRect(BOXSIZE*3, 0, BOXSIZE, BOXSIZE, ILI9341_WHITE);
} else if (p.x < BOXSIZE*5) {
currentcolor = ILI9341_BLUE;
tft.drawRect(BOXSIZE*4, 0, BOXSIZE, BOXSIZE, ILI9341_WHITE);
} else if (p.x < BOXSIZE*6) {
currentcolor = ILI9341_MAGENTA;
tft.drawRect(BOXSIZE*5, 0, BOXSIZE, BOXSIZE, ILI9341_WHITE);
} else if (p.x < BOXSIZE*7) {
currentcolor = ILI9341_WHITE;
tft.drawRect(BOXSIZE*6, 0, BOXSIZE, BOXSIZE, ILI9341_RED);
} else if (p.x < BOXSIZE*8) {
currentcolor = ILI9341_BLACK;
tft.drawRect(BOXSIZE*7, 0, BOXSIZE, BOXSIZE, ILI9341_WHITE);
}
if (oldcolor != currentcolor) {
if (oldcolor == ILI9341_RED)
tft.fillRect(0, 0, BOXSIZE, BOXSIZE, ILI9341_RED);
if (oldcolor == ILI9341_YELLOW)
tft.fillRect(BOXSIZE, 0, BOXSIZE, BOXSIZE, ILI9341_YELLOW);
if (oldcolor == ILI9341_GREEN)
tft.fillRect(BOXSIZE*2, 0, BOXSIZE, BOXSIZE, ILI9341_GREEN);
if (oldcolor == ILI9341_CYAN)
tft.fillRect(BOXSIZE*3, 0, BOXSIZE, BOXSIZE, ILI9341_CYAN);
if (oldcolor == ILI9341_BLUE)
tft.fillRect(BOXSIZE*4, 0, BOXSIZE, BOXSIZE, ILI9341_BLUE);
if (oldcolor == ILI9341_MAGENTA)
tft.fillRect(BOXSIZE*5, 0, BOXSIZE, BOXSIZE, ILI9341_MAGENTA);
if (oldcolor == ILI9341_WHITE)
tft.fillRect(BOXSIZE*6, 0, BOXSIZE, BOXSIZE, ILI9341_WHITE);
if (oldcolor == ILI9341_BLACK)
tft.fillRect(BOXSIZE*7, 0, BOXSIZE, BOXSIZE, ILI9341_BLACK);
}
}
if (((p.y-PENRADIUS) > BOXSIZE) && ((p.y+PENRADIUS) < tft.height())) {
tft.fillCircle(p.x, p.y, PENRADIUS, currentcolor);
}
}