Hello.
I want to use a 3.5 inch RPi LCD + Touchscreen with the Teensy 4.0. The display can be seen here. I know the page is not in English, but I could not find something else. At least, you can see how it looks like.
I made a small hardware modification to the display in order to make it work with 3.3V instead of the 5V supplied by the Raspberry Pi.
You can see the modification in the image bellow (I have to clean the flux from the black PCB in which the display is soldered). I just removed the LDO and bridged the IN and OUT traces. Now the display turns on.
I have connected it to the Teensy 4.0 like this:
And the 3.3V and GND of course.
I used this image for determining the pins:
I used the graphics test sketch from the Examples in the Arduino IDE (Examples > ILI9341_t3 > graphicstest)
Here is the code:
I also used this code with a
The problem is that the display is not working. It is just a white screen. I tried other examples too but nothing made the screen display something.
When I run the above code the Serial monitor shows this:
The touchscreen is working. I tested it with the XPT2046_Touchscreen example code in the Arduino IDE examples folder (the one that comes with Teensyduino) and it shows the X and Y coordinates of the touch and the pressure.
If instead of the #define TFT_CS 26 i use #define TFT_CS 2 (the CS pin for the touchscreen) the Serial Monitor shows this:
Am I doing something wrong? What could be the problem?
Thank you very much in advance for your time.
I want to use a 3.5 inch RPi LCD + Touchscreen with the Teensy 4.0. The display can be seen here. I know the page is not in English, but I could not find something else. At least, you can see how it looks like.
I made a small hardware modification to the display in order to make it work with 3.3V instead of the 5V supplied by the Raspberry Pi.
You can see the modification in the image bellow (I have to clean the flux from the black PCB in which the display is soldered). I just removed the LDO and bridged the IN and OUT traces. Now the display turns on.
I have connected it to the Teensy 4.0 like this:
And the 3.3V and GND of course.
I used this image for determining the pins:
I used the graphics test sketch from the Examples in the Arduino IDE (Examples > ILI9341_t3 > graphicstest)
Here is the code:
Code:
/***************************************************
This is our GFX example for the Adafruit ILI9341 Breakout and Shield
----> http://www.adafruit.com/products/1651
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
****************************************************/
#include "SPI.h"
#include "ILI9341_t3.h"
#include "font_Arial.h"
// For the Adafruit shield, these are the default.
#define TFT_DC 27
#define TFT_CS 26
// Use hardware SPI (on Uno, #13, #12, #11) and the above for CS/DC
ILI9341_t3 tft = ILI9341_t3(TFT_CS, TFT_DC);
void setup() {
tft.begin();
// Note: you can now set the SPI speed to any value
// the default value is 30Mhz, but most ILI9341 displays
// can handle at least 60Mhz and as much as 100Mhz
// tft.setClock(60000000);
tft.fillScreen(ILI9341_BLACK);
tft.setTextColor(ILI9341_YELLOW);
tft.setTextSize(2);
tft.println("Waiting for Arduino Serial Monitor...");
Serial.begin(9600);
while (!Serial) ; // wait for Arduino Serial Monitor
Serial.println("ILI9341 Test!");
// read diagnostics (optional but can help debug problems)
uint8_t x = tft.readcommand8(ILI9341_RDMODE);
Serial.print("Display Power Mode: 0x"); Serial.println(x, HEX);
x = tft.readcommand8(ILI9341_RDMADCTL);
Serial.print("MADCTL Mode: 0x"); Serial.println(x, HEX);
x = tft.readcommand8(ILI9341_RDPIXFMT);
Serial.print("Pixel Format: 0x"); Serial.println(x, HEX);
x = tft.readcommand8(ILI9341_RDIMGFMT);
Serial.print("Image Format: 0x"); Serial.println(x, HEX);
x = tft.readcommand8(ILI9341_RDSELFDIAG);
Serial.print("Self Diagnostic: 0x"); Serial.println(x, HEX);
Serial.println(F("Benchmark Time (microseconds)"));
Serial.print(F("Screen fill "));
Serial.println(testFillScreen());
delay(200);
Serial.print(F("Text "));
Serial.println(testText());
delay(600);
Serial.print(F("Proportional Text "));
Serial.println(testProportionalText());
delay(600);
Serial.print(F("Lines "));
Serial.println(testLines(ILI9341_CYAN));
delay(200);
Serial.print(F("Horiz/Vert Lines "));
Serial.println(testFastLines(ILI9341_RED, ILI9341_BLUE));
delay(200);
Serial.print(F("Rectangles (outline) "));
Serial.println(testRects(ILI9341_GREEN));
delay(200);
Serial.print(F("Rectangles (filled) "));
Serial.println(testFilledRects(ILI9341_YELLOW, ILI9341_MAGENTA));
delay(200);
Serial.print(F("Circles (filled) "));
Serial.println(testFilledCircles(10, ILI9341_MAGENTA));
Serial.print(F("Circles (outline) "));
Serial.println(testCircles(10, ILI9341_WHITE));
delay(200);
Serial.print(F("Triangles (outline) "));
Serial.println(testTriangles());
delay(200);
Serial.print(F("Triangles (filled) "));
Serial.println(testFilledTriangles());
delay(200);
Serial.print(F("Rounded rects (outline) "));
Serial.println(testRoundRects());
delay(200);
Serial.print(F("Rounded rects (filled) "));
Serial.println(testFilledRoundRects());
delay(200);
Serial.println(F("Done!"));
}
void loop(void) {
for(uint8_t rotation=0; rotation<4; rotation++) {
tft.setRotation(rotation);
testText();
delay(1000);
}
}
unsigned long testFillScreen() {
unsigned long start = micros();
tft.fillScreen(ILI9341_BLACK);
tft.fillScreen(ILI9341_RED);
tft.fillScreen(ILI9341_GREEN);
tft.fillScreen(ILI9341_BLUE);
tft.fillScreen(ILI9341_BLACK);
return micros() - start;
}
unsigned long testText() {
tft.fillScreen(ILI9341_BLACK);
unsigned long start = micros();
tft.setCursor(0, 0);
tft.setTextColor(ILI9341_WHITE); tft.setTextSize(1);
tft.println("Hello World!");
tft.setTextColor(ILI9341_YELLOW); tft.setTextSize(2);
tft.println(1234.56);
tft.setTextColor(ILI9341_RED); tft.setTextSize(3);
tft.println(0xDEADBEEF, HEX);
tft.println();
tft.setTextColor(ILI9341_GREEN);
tft.setTextSize(5);
tft.println("Groop");
tft.setTextSize(2);
tft.println("I implore thee,");
tft.setTextSize(1);
tft.println("my foonting turlingdromes.");
tft.println("And hooptiously drangle me");
tft.println("with crinkly bindlewurdles,");
tft.println("Or I will rend thee");
tft.println("in the gobberwarts");
tft.println("with my blurglecruncheon,");
tft.println("see if I don't!");
return micros() - start;
}
unsigned long testProportionalText() {
tft.fillScreen(ILI9341_BLACK);
unsigned long start = micros();
tft.setCursor(0, 0);
tft.setTextColor(ILI9341_WHITE); tft.setFont(Arial_10);
tft.println("Hello World!");
tft.setTextColor(ILI9341_YELLOW); tft.setFont(Arial_16);
tft.println(1234.56);
tft.setTextColor(ILI9341_RED); tft.setFont(Arial_24);
tft.println(0xDEADBEEF, HEX);
tft.println();
tft.setTextColor(ILI9341_GREEN);
tft.setFont(Arial_40);
tft.println("Groop");
tft.setFont(Arial_16);
tft.println("I implore thee,");
tft.setFont(Arial_10);
tft.println("my foonting turlingdromes.");
tft.println("And hooptiously drangle me");
tft.println("with crinkly bindlewurdles,");
tft.println("Or I will rend thee");
tft.println("in the gobberwarts");
tft.println("with my blurglecruncheon,");
tft.println("see if I don't!");
tft.setFontAdafruit();
return micros() - start;
}
unsigned long testLines(uint16_t color) {
unsigned long start, t;
int x1, y1, x2, y2,
w = tft.width(),
h = tft.height();
tft.fillScreen(ILI9341_BLACK);
x1 = y1 = 0;
y2 = h - 1;
start = micros();
for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color);
x2 = w - 1;
for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color);
t = micros() - start; // fillScreen doesn't count against timing
tft.fillScreen(ILI9341_BLACK);
x1 = w - 1;
y1 = 0;
y2 = h - 1;
start = micros();
for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color);
x2 = 0;
for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color);
t += micros() - start;
tft.fillScreen(ILI9341_BLACK);
x1 = 0;
y1 = h - 1;
y2 = 0;
start = micros();
for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color);
x2 = w - 1;
for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color);
t += micros() - start;
tft.fillScreen(ILI9341_BLACK);
x1 = w - 1;
y1 = h - 1;
y2 = 0;
start = micros();
for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color);
x2 = 0;
for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color);
return micros() - start;
}
unsigned long testFastLines(uint16_t color1, uint16_t color2) {
unsigned long start;
int x, y, w = tft.width(), h = tft.height();
tft.fillScreen(ILI9341_BLACK);
start = micros();
for(y=0; y<h; y+=5) tft.drawFastHLine(0, y, w, color1);
for(x=0; x<w; x+=5) tft.drawFastVLine(x, 0, h, color2);
return micros() - start;
}
unsigned long testRects(uint16_t color) {
unsigned long start;
int n, i, i2,
cx = tft.width() / 2,
cy = tft.height() / 2;
tft.fillScreen(ILI9341_BLACK);
n = min(tft.width(), tft.height());
start = micros();
for(i=2; i<n; i+=6) {
i2 = i / 2;
tft.drawRect(cx-i2, cy-i2, i, i, color);
}
return micros() - start;
}
unsigned long testFilledRects(uint16_t color1, uint16_t color2) {
unsigned long start, t = 0;
int n, i, i2,
cx = tft.width() / 2 - 1,
cy = tft.height() / 2 - 1;
tft.fillScreen(ILI9341_BLACK);
n = min(tft.width(), tft.height()) - 1;
for(i=n; i>0; i-=6) {
i2 = i / 2;
start = micros();
tft.fillRect(cx-i2, cy-i2, i, i, color1);
t += micros() - start;
// Outlines are not included in timing results
tft.drawRect(cx-i2, cy-i2, i, i, color2);
}
return t;
}
unsigned long testFilledCircles(uint8_t radius, uint16_t color) {
unsigned long start;
int x, y, w = tft.width(), h = tft.height(), r2 = radius * 2;
tft.fillScreen(ILI9341_BLACK);
start = micros();
for(x=radius; x<w; x+=r2) {
for(y=radius; y<h; y+=r2) {
tft.fillCircle(x, y, radius, color);
}
}
return micros() - start;
}
unsigned long testCircles(uint8_t radius, uint16_t color) {
unsigned long start;
int x, y, r2 = radius * 2,
w = tft.width() + radius,
h = tft.height() + radius;
// Screen is not cleared for this one -- this is
// intentional and does not affect the reported time.
start = micros();
for(x=0; x<w; x+=r2) {
for(y=0; y<h; y+=r2) {
tft.drawCircle(x, y, radius, color);
}
}
return micros() - start;
}
unsigned long testTriangles() {
unsigned long start;
int n, i, cx = tft.width() / 2 - 1,
cy = tft.height() / 2 - 1;
tft.fillScreen(ILI9341_BLACK);
n = min(cx, cy);
start = micros();
for(i=0; i<n; i+=5) {
tft.drawTriangle(
cx , cy - i, // peak
cx - i, cy + i, // bottom left
cx + i, cy + i, // bottom right
tft.color565(0, 0, i));
}
return micros() - start;
}
unsigned long testFilledTriangles() {
unsigned long start, t = 0;
int i, cx = tft.width() / 2 - 1,
cy = tft.height() / 2 - 1;
tft.fillScreen(ILI9341_BLACK);
start = micros();
for(i=min(cx,cy); i>10; i-=5) {
start = micros();
tft.fillTriangle(cx, cy - i, cx - i, cy + i, cx + i, cy + i,
tft.color565(0, i, i));
t += micros() - start;
tft.drawTriangle(cx, cy - i, cx - i, cy + i, cx + i, cy + i,
tft.color565(i, i, 0));
}
return t;
}
unsigned long testRoundRects() {
unsigned long start;
int w, i, i2,
cx = tft.width() / 2 - 1,
cy = tft.height() / 2 - 1;
tft.fillScreen(ILI9341_BLACK);
w = min(tft.width(), tft.height()) - 1;
start = micros();
for(i=0; i<w; i+=6) {
i2 = i / 2;
tft.drawRoundRect(cx-i2, cy-i2, i, i, i/8, tft.color565(i, 0, 0));
}
return micros() - start;
}
unsigned long testFilledRoundRects() {
unsigned long start;
int i, i2,
cx = tft.width() / 2 - 1,
cy = tft.height() / 2 - 1;
tft.fillScreen(ILI9341_BLACK);
start = micros();
for(i=min(tft.width(), tft.height()) - 1; i>20; i-=6) {
i2 = i / 2;
tft.fillRoundRect(cx-i2, cy-i2, i, i, i/8, tft.color565(0, i, 0));
}
return micros() - start;
}
I also used this code with a
Code:
# define TFT_RST 30
...
ILI9341_t3 tft = ILI9341_t3(TFT_CS, TFT_DC, TFT_RST);
When I run the above code the Serial monitor shows this:
The touchscreen is working. I tested it with the XPT2046_Touchscreen example code in the Arduino IDE examples folder (the one that comes with Teensyduino) and it shows the X and Y coordinates of the touch and the pressure.
If instead of the #define TFT_CS 26 i use #define TFT_CS 2 (the CS pin for the touchscreen) the Serial Monitor shows this:
Am I doing something wrong? What could be the problem?
Thank you very much in advance for your time.