setContrast not working with NodeMCU and ST7565 board

[JohannieK]

Expected behavior

Contrast of the display should change when calling setContrast

Actual behavior

no change in display contrast

Test code

#include <Arduino.h>
#include <U8g2lib.h>

#ifdef U8X8_HAVE_HW_SPI
#include <SPI.h>
#endif
#ifdef U8X8_HAVE_HW_I2C
#include <Wire.h>
#endif

U8G2_ST7565_JLX12864_F_4W_HW_SPI u8g2(U8G2_R0, /* cs=/ D3, / dc=/ D2, / reset=*/ D4);

void u8g2_prepare(void) {
u8g2.setFont(u8g2_font_6x10_tf);
u8g2.setFontRefHeightExtendedText();
u8g2.setDrawColor(1);
u8g2.setFontPosTop();
u8g2.setFontDirection(0);
}

void setup(void) {
Serial.begin(115200);
Serial.println(" ");
Serial.println("Starting up");
u8g2.begin();

Serial.println("Started up");
}

byte ct = 0;
char buff[10];

void loop(void) {
Serial.print("Contrast : ");
Serial.println(ct);
// picture loop
u8g2.setContrast(ct);
u8g2.clearBuffer();
u8g2_prepare();
dtostrf(ct,5,0,buff);
u8g2.drawStr(1,1,buff);
u8g2.sendBuffer();

ct++;
if (ct>=255)
ct = 0;

// deley between each page
delay(100);

}

NodeMCU startup banner

I don't know how to get this. This is the board I'm using: https://www.banggood.com/5Pcs-NodeMcu-Lua-WIFI-Internet-Things-Development-Board-Based-ESP8266-CP2102-Wireless-Module-p-1121408.html?rmmds=myorder&cur_warehouse=CN

Hardware

NodeMCU board: https://www.banggood.com/5Pcs-NodeMcu-Lua-WIFI-Internet-Things-Development-Board-Based-ESP8266-CP2102-Wireless-Module-p-1121408.html?rmmds=myorder&cur_warehouse=CN
St7565 Display: https://www.banggood.com/OPEN-SMART-3_3V-2_4-inch-128+64-Serial-SPI-Monochrome-LCD-Display-Board-Module-without-Backlight-for-Arduino-UN0-Nano-p-1901540.html?rmmds=myorder&cur_warehouse=CN

[JohannieK]

Sorry for posting here. Should have been in the u8g2 project.