microSD card module and 2.2" 18-bit color TFT LCD display not working together

Other Hardware Storage
1

When attempting to write to the external microSD module fails when the screen is also driven. Only during initialisation before writing to the screen can write to the sd card. I cannot currently find a cause for this behaviour.

#include <Arduino.h>

// clock module
#include "clock.h"

// LCD
void LCDSetup();

#include "Adafruit_GFX.h"
#include "Adafruit_ILI9341.h"
#include "SPI.h"

#define TFT_DC 7
#define TFT_CS 3
#define TFT_RST 5

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);

void writeLine1();
void writeLine2();
void writeLine3();

char previousLine1[100];
char previousLine2[100];
char previousLine3[100];

unsigned long previousMillis = 0;

uint8_t previousSecond = 0;
void writeDataToScreen();

// SD
const int chipSelect = 4;
#include <SdFat.h>
SdFat sd;
SdFile myFile;

void SDSetup();
void testWriteToSd();

void setup() {
  Serial.begin(9600);
  while (!Serial) {
  }
  Serial.println();

  clockSetup();
  LCDSetup();
}

void loop() {
  writeDataToScreen();
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= 1000) {
    testWriteToSd();
    previousMillis = currentMillis;
  }
}

void writeDataToScreen() {
  writeLine1();
}

void writeLine1() {
  uint16_t year = getYear();
  uint8_t month = getMonth();
  uint8_t day = getDay();
  uint8_t hour = getHour24();
  uint8_t minute = getMinute();
  uint8_t second = getSecond();

  char line1[100];
  snprintf(line1, 100, "%04d-%02d-%02d T%02d:%02d:%02d", year, month, day, hour,
           minute, second);

  if (previousSecond != second) {
    previousSecond = second;
    tft.setCursor(0, 0);
    tft.setTextColor(ILI9341_BLACK);
    tft.setTextSize(2);
    tft.println(previousLine1);
    strcpy(previousLine1, line1);
    tft.setCursor(0, 0);
    tft.setTextColor(ILI9341_GREEN);
    tft.setTextSize(2);
    tft.println(line1);
  }
}

void LCDSetup() {
  tft.begin();
  tft.fillScreen(ILI9341_BLACK);
}

void SDSetup() {
  if (!sd.begin(chipSelect, SPI_EIGHTH_SPEED)) {
    sd.initErrorHalt();
  }
}

void testWriteToSd() {
  if (!myFile.open("test.txt", O_RDWR | O_CREAT | O_AT_END)) {
    sd.errorHalt(F("opening test.txt for write failed"));
  }
  Serial.println(F("Writing to test.txt..."));
  myFile.println(F("testing 1, 2, 3."));
  myFile.close();
  Serial.println(F("done writing."));
}
2

They are both connected to the SPI pins, right? Did you verify that it doesn't confict? Please post a good wiring diagram (no Fritzing or verbal descriptions please...).

3

The display is connected via the Adafruit EYESPI Breakout Board.

image
image997×554 17.5 KB

4

Thank you. Where in the code is the SD chip select signal CS on pin D4 specified? Never mind, I see it now...

5

Which Arduino?

The TFT and SD libraries use up a lot of RAM, and you may be running out.

1 Like
6

Arduino Mega 2560 Rev3

7

Is there a way to make it work?

8

Basically since they share the same SPI port, you will have to manually enable these devices. easiest is o do this in the functions that deal with one of the devices and i suggest the sd card.
so

void SDSetup() {
  digitalWrite(TFT_CS, HIGH);  // the chipselect is active LOW
  if (!sd.begin(chipSelect, SPI_EIGHTH_SPEED)) {
    sd.initErrorHalt();
  }
  digitalWrite(chipselect, HIGH);
  digitalWrite(TFT_CS, LOW);
}

and

void testWriteToSd() {
  digitalWrite(TFT_CS, HIGH);  
  digitalWrite(chipselect, LOW);
  if (!myFile.open("test.txt", O_RDWR | O_CREAT | O_AT_END)) {
    sd.errorHalt(F("opening test.txt for write failed"));
  }
  Serial.println(F("Writing to test.txt..."));
  myFile.println(F("testing 1, 2, 3."));
  myFile.close();
  Serial.println(F("done writing."));
  digitalWrite(chipselect, HIGH);
  digitalWrite(TFT_CS, LOW);
}
9

I tried this solution but it doesn't work. I think the libraries implement this by default.

10

I get the SdError: 0X2B,0X0 error in the sdfat library.

11

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