TFT display turns black when wifi is enabled

Other Hardware Displays
1

Hello I have following sketch:

#include "tft_setup.h"
#include"TFT_eSPI.h"
#include <WiFi.h>
#include "esp_wifi.h"

const char *wlan_ssid = "jsf-yxxxx";
const char *wlan_password = "*****";


WiFiClient espClient;
esp_err_t err;

unsigned long startTime;

const String client_id = "esp32-office";


#define ST7735_DRIVER
#define ST7735_BLACKTAB
   
#define TFT_WIDTH  128
#define TFT_HEIGHT 160

#define TFT_RGB_ORDER TFT_RGB  

// WEMOLS Lolin32 lite
#define TFT_CS    5   
#define TFT_RST   16  
#define TFT_DC    17   
#define TFT_BL    25   // LED back-light
#define TFT_BACKLIGHT_ON HIGH

TFT_eSPI tft = TFT_eSPI();

void turnInto3v(uint8_t pin) {
  pinMode(pin, OUTPUT);
  digitalWrite(pin, 1);
}


void setup(void) {
  Serial.begin(115200);

  turnInto3v(26);
  turnInto3v(33);

  //initWifi();
  initTft();

}

void initTft() {
  Serial.println("Init tft");
  tft.init();
  tft.fillScreen(TFT_BLACK);  
  tft.setRotation(1);

  tft.setCursor(15, 50, 1);  
  tft.setTextColor(TFT_WHITE, TFT_BLACK);
  tft.setTextSize(2);
  tft.println("It works");
  tft.drawRect(10, 40, 145, 40, TFT_YELLOW);  

  Serial.println("Tft ok?");
  delay(2000);


  tft.drawRect(10, 40, 145, 40, TFT_RED); 
}

void initWifi() {
  // Bring up the WiFi connection
  WiFi.setHostname(client_id.c_str());

  tft.print("Wifi connect: ");

  // Dsiplay turns black
  WiFi.begin(wlan_ssid, wlan_password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    tft.print(".");
  }
  tft.println("+");

  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());

  tft.println("IP address: " + WiFi.localIP().toString(false));

  startTime = millis();

  // Give user time to read
  delay(1500);
}

void loop() { }

I have 2 scenarios:
1.) tfft before wifi

  • i run "initTft();" and the tft is displaying my expected text
  • then i run "initWifi();" as soon as "WiFi.begin" is reachted, the display is turning black but the esp32(wroom32) is reachable via wifi.

2.) wifi before tft

  • i run "initWifi();" and the esp32 is reachable via wifi as expected.
  • then i run "initTft();" and the display is turning on but stay all white. Nothing will be displayed.

I tried already:

  • using: TFT_eSPI with hardware VSPI
  • using: Adafruit_ST7735 with hardware VSPI
  • using: Adafruit_ST7735 with software SPI (and different pins)

Do some one know how to get the TFT and Wifi working at the same time?

2

What is powering your project? Maybe show us a photo of a hand-drawn schematic.

3

I wired the wrom32:
https://de.aliexpress.com/item/1005006606502197.html

to the display:
https://de.aliexpress.com/item/1005005396134138.html

like this:

image-60
image-60510×837 47.9 KB

  • gnd gnd
  • vcc 3v
  • sck D14 serial clock
  • sda D13 serial data aka mosi
  • res D26 lcm reset permanent 3v
  • dc D12 data command aka miso aka dc
  • cs D15 chip select
  • bl D25 back ligtht permanent 3v
4

I tested now:

  • same code
  • same wiring
  • different esp32 vendor

It works with:
https://de.aliexpress.com/item/1005005776600877.html?spm=a2g0o.order_list.order_list_main.75.782e5c5fMSTJW7&gatewayAdapt=glo2deu

5

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