local_dani_21
Well-known member
Hi
I'm using a teensy 3.1 to drive three TFT's over (hardware-line-driven) SPI. That works like a charm.
However, to my device, I have also a pushbutton attached (with 10k pullup resistor), connected to pin 16.
However, when running the following code, digitalRead(16) always returns 0.
If I use the example code by Tom I (see following code), the pushbutton works as expected.
Is digitalRead somehow influenced by SPI?
Thank you,
Dani
I'm using a teensy 3.1 to drive three TFT's over (hardware-line-driven) SPI. That works like a charm.
However, to my device, I have also a pushbutton attached (with 10k pullup resistor), connected to pin 16.
However, when running the following code, digitalRead(16) always returns 0.
Code:
#include <SPI.h>
#include "Adafruit_GFX.h"
#include "Adafruit_RA8875.h"
#include <SD.h>
#define sd_cs 10
#define tasten_pin 16
// Library only supports hardware SPI at this time
// Connect SCLK to UNO Digital #13 (Hardware SPI clock)
// Connect MISO to UNO Digital #12 (Hardware SPI MISO)
// Connect MOSI to UNO Digital #11 (Hardware SPI MOSI)
#define RA8875_CS 9
#define RA8875_CS_2 6
#define RA8875_CS_3 2
#define RA8875_RESET 3
Adafruit_RA8875 tft1 = Adafruit_RA8875(RA8875_CS);
Adafruit_RA8875 tft2 = Adafruit_RA8875(RA8875_CS_2);
Adafruit_RA8875 tft3 = Adafruit_RA8875(RA8875_CS_3);
uint16_t tx, ty;
void setup()
{
Serial.begin(57600);
while(!Serial){}
if (!SD.begin(sd_cs))
{
Serial.println("SD initialization failed!");
return;
}
Serial.println("SD initialization done.");
Serial.println("Press the Button!");
while(digitalRead(16) == LOW){} // is low forever ...
reset_tfts(RA8875_RESET); // Resetting manually to be able to use a common reset-line for all TFT's
Serial.println("RA8875 1 start");
/* Initialise the display using 'RA8875_480x272' or 'RA8875_800x480' */
if (!tft1.begin_without_reset(RA8875_800x480)) {
Serial.println("RA8875 1 Not Found!");
while (1);
}
Serial.println("Found RA8875");
Serial.println("RA8875 2 start");
/* Initialise the display using 'RA8875_480x272' or 'RA8875_800x480' */
if (!tft2.begin_without_reset(RA8875_800x480)) {
Serial.println("RA8875 2 Not Found!");
while (1);
}
Serial.println("Found RA8875 2");
Serial.println("RA8875 3 start");
/* Initialise the display using 'RA8875_480x272' or 'RA8875_800x480' */
if (!tft3.begin_without_reset(RA8875_800x480)) {
Serial.println("RA8875 3 Not Found!");
while (1);
}
Serial.println("Found RA8875 3");
tftSetup(&tft1);
tftSetup(&tft2);
tftSetup(&tft3);
}
void loop() {
long int next_update;
int update_intervall = 30000; // 30 Sekunden
bmpDraw(&tft1, "1a.bmp", 0, 0); bmpDraw(&tft2, "1b.bmp", 0, 0); bmpDraw(&tft3, "1c.bmp", 0, 0);
next_update = millis() + update_intervall;
Serial.print(digitalRead(tasten_pin));
Serial.print(" ");
Serial.print(millis());
Serial.println(next_update);
while(millis() < next_update && digitalRead(tasten_pin) == HIGH){}
bmpDraw(&tft1, "2a.bmp", 0, 0); bmpDraw(&tft2, "2b.bmp", 0, 0); bmpDraw(&tft3, "2c.bmp", 0, 0);
next_update = millis() + update_intervall;
Serial.print(digitalRead(tasten_pin));
Serial.print(" ");
Serial.print(millis());
Serial.println(next_update);
while(millis() < next_update && digitalRead(tasten_pin) == HIGH){}
bmpDraw(&tft1, "3a.bmp", 0, 0); bmpDraw(&tft2, "3b.bmp", 0, 0); bmpDraw(&tft3, "3c.bmp", 0, 0);
next_update = millis() + update_intervall;
while(millis() < next_update && digitalRead(tasten_pin) == HIGH){}
bmpDraw(&tft1, "4a.bmp", 0, 0); bmpDraw(&tft2, "4b.bmp", 0, 0); bmpDraw(&tft3, "4c.bmp", 0, 0);
next_update = millis() + update_intervall;
while(millis() < next_update && digitalRead(tasten_pin) == HIGH){}
}
void tftSetup(Adafruit_RA8875 *tft)
{
tft->displayOn(true);
tft->GPIOX(true); // Enable TFT - display enable tied to GPIOX
tft->PWM1config(true, RA8875_PWM_CLK_DIV1024); // PWM output for backlight
tft->PWM1out(255);
// With hardware accelleration this is instant
tft->fillScreen(RA8875_WHITE);
}
#define BUFFPIXEL 20
void bmpDraw(Adafruit_RA8875 *tft, char *filename, int x, int y) {
File bmpFile;
int bmpWidth, bmpHeight; // W+H in pixels
uint8_t bmpDepth; // Bit depth (currently must be 24)
uint32_t bmpImageoffset; // Start of image data in file
uint32_t rowSize; // Not always = bmpWidth; may have padding
uint8_t sdbuffer[3*BUFFPIXEL]; // pixel in buffer (R+G+B per pixel)
uint16_t lcdbuffer[BUFFPIXEL]; // pixel out buffer (16-bit per pixel)
uint8_t buffidx = sizeof(sdbuffer); // Current position in sdbuffer
boolean goodBmp = false; // Set to true on valid header parse
boolean flip = true; // BMP is stored bottom-to-top
int w, h, row, col;
uint8_t r, g, b;
uint32_t pos = 0, startTime = millis();
uint8_t lcdidx = 0;
boolean first = true;
if((x >= tft->width()) || (y >= tft->height())) return;
Serial.println();
Serial.print(F("Loading image '"));
Serial.print(filename);
Serial.println('\'');
// Open requested file on SD card
if ((bmpFile = SD.open(filename)) == NULL) {
Serial.println(F("File not found"));
return;
}
// Parse BMP header
if(read16(bmpFile) == 0x4D42) { // BMP signature
Serial.println(F("File size: "));
Serial.println(read32(bmpFile));
(void)read32(bmpFile); // Read & ignore creator bytes
bmpImageoffset = read32(bmpFile); // Start of image data
Serial.print(F("Image Offset: "));
Serial.println(bmpImageoffset, DEC);
// Read DIB header
Serial.print(F("Header size: "));
Serial.println(read32(bmpFile));
bmpWidth = read32(bmpFile);
bmpHeight = read32(bmpFile);
if(read16(bmpFile) == 1) { // # planes -- must be '1'
bmpDepth = read16(bmpFile); // bits per pixel
Serial.print(F("Bit Depth: "));
Serial.println(bmpDepth);
if((bmpDepth == 24) && (read32(bmpFile) == 0)) { // 0 = uncompressed
goodBmp = true; // Supported BMP format -- proceed!
Serial.print(F("Image size: "));
Serial.print(bmpWidth);
Serial.print('x');
Serial.println(bmpHeight);
// BMP rows are padded (if needed) to 4-byte boundary
rowSize = (bmpWidth * 3 + 3) & ~3;
// If bmpHeight is negative, image is in top-down order.
// This is not canon but has been observed in the wild.
if(bmpHeight < 0) {
bmpHeight = -bmpHeight;
flip = false;
}
// Crop area to be loaded
w = bmpWidth;
h = bmpHeight;
if((x+w-1) >= tft->width()) w = tft->width() - x;
if((y+h-1) >= tft->height()) h = tft->height() - y;
// Set TFT address window to clipped image bounds
for (row=0; row<h; row++) { // For each scanline...
// Seek to start of scan line. It might seem labor-
// intensive to be doing this on every line, but this
// method covers a lot of gritty details like cropping
// and scanline padding. Also, the seek only takes
// place if the file position actually needs to change
// (avoids a lot of cluster math in SD library).
if(flip) // Bitmap is stored bottom-to-top order (normal BMP)
pos = bmpImageoffset + (bmpHeight - 1 - row) * rowSize;
else // Bitmap is stored top-to-bottom
pos = bmpImageoffset + row * rowSize;
if(bmpFile.position() != pos) { // Need seek?
bmpFile.seek(pos);
buffidx = sizeof(sdbuffer); // Force buffer reload
}
for (col=0; col<w; col++) { // For each column...
// Time to read more pixel data?
if (buffidx >= sizeof(sdbuffer)) { // Indeed
// Push LCD buffer to the display first
if(lcdidx > 0) {
tft->drawPixel(col, row, lcdbuffer[lcdidx]);
lcdidx = 0;
first = false;
}
bmpFile.read(sdbuffer, sizeof(sdbuffer));
buffidx = 0; // Set index to beginning
}
// Convert pixel from BMP to TFT format
b = sdbuffer[buffidx++];
g = sdbuffer[buffidx++];
r = sdbuffer[buffidx++];
lcdbuffer[lcdidx] = color565(r,g,b);
tft->drawPixel(col, row, lcdbuffer[lcdidx]);
} // end pixel
} // end scanline
// Write any remaining data to LCD
if(lcdidx > 0) {
tft->drawPixel(col, row, lcdbuffer[lcdidx]);
}
Serial.print(F("Loaded in "));
Serial.print(millis() - startTime);
Serial.println(" ms");
} // end goodBmp
}
}
bmpFile.close();
if(!goodBmp) Serial.println(F("BMP format not recognized."));
}
// These read 16- and 32-bit types from the SD card file.
// BMP data is stored little-endian, Arduino is little-endian too.
// May need to reverse subscript order if porting elsewhere.
uint16_t read16(File f) {
uint16_t result;
((uint8_t *)&result)[0] = f.read(); // LSB
((uint8_t *)&result)[1] = f.read(); // MSB
return result;
}
uint32_t read32(File f) {
uint32_t result;
((uint8_t *)&result)[0] = f.read(); // LSB
((uint8_t *)&result)[1] = f.read();
((uint8_t *)&result)[2] = f.read();
((uint8_t *)&result)[3] = f.read(); // MSB
return result;
}
uint16_t color565(uint8_t r, uint8_t g, uint8_t b) {
return ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | (b >> 3);
}
byte decToBcd(byte val){
// Convert normal decimal numbers to binary coded decimal
return ( (val/10*16) + (val%10) );
}
void reset_tfts(int reset_pin){
pinMode(reset_pin, OUTPUT);
digitalWrite(reset_pin, LOW);
delay(100);
digitalWrite(reset_pin, HIGH);
delay(100);
}If I use the example code by Tom I (see following code), the pushbutton works as expected.
Code:
/*
Button
Turns on and off a light emitting diode(LED) connected to digital
pin 13, when pressing a pushbutton attached to pin 2.
The circuit:
* pushbutton attached to pin 16 from ground
* 10K resistor attached to pin 16 from +5V (pullup)
created 2005
by DojoDave <http://www.0j0.org>
modified 30 Aug 2011
by Tom Igoe
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/Button
*/
// constants won't change. They're used here to
// set pin numbers:
const int buttonPin = 16; // the number of the pushbutton pin
const int ledPin = 13; // the number of the LED pin
// Pin 13: Arduino has an LED connected on pin 13
// Pin 11: Teensy 2.0 has the LED on pin 11
// Pin 6: Teensy++ 2.0 has the LED on pin 6
// Pin 13: Teensy 3.0 has the LED on pin 13
// variables will change:
int buttonState = 0; // variable for reading the pushbutton status
void setup() {
// initialize the LED pin as an output:
pinMode(ledPin, OUTPUT);
// initialize the pushbutton pin as an input:
pinMode(buttonPin, INPUT);
}
void loop(){
// read the state of the pushbutton value:
buttonState = digitalRead(buttonPin);
// check if the pushbutton is pressed.
// if it is, the buttonState is HIGH:
if (buttonState == HIGH) {
// turn LED on:
digitalWrite(ledPin, HIGH);
}
else {
// turn LED off:
digitalWrite(ledPin, LOW);
}
}Is digitalRead somehow influenced by SPI?
Thank you,
Dani
