SSD1306 Display is not working with Bluepill Board STM32F103

[Jaishankar872]

Hardware Details

MCU - Bluepill STM32F103CB
OLED SSD1306 128x32 I2C display
PA3 - SDA
PA4 - SCL

Code (in PlatformIO)

First I used the softwire library's scanner code to validate the I2C connection of PA3(SDA) & PA4 (SCL). Got the Slave address as 0x3C
With the below code Display is not working(showing nothing)

#include <U8g2lib.h>
U8G2_SSD1306_128X32_UNIVISION_F_SW_I2C display(U8G2_R0, PA4, PA3, U8X8_PIN_NONE);
void setup()
{
display.begin();
}
void loop()
{
  display.clearBuffer();
  display.setFont(u8g2_font_ncenB08_tr);
  display.drawStr(0, 10, "Hello STM32!");
  display.sendBuffer();
  delay(1000);
}

Digital Logic analyzer waveform output

Problem Statement

After seeing the code and Logic analyzer waveform, there are some issue configuration in the code while use U8g2lib library. Please help here solve this issue

Thanks in Advance!!!

[olikraus]

Difficult.
So far i personally have only used Arduino IDE. Moreover I how only "official" boards. So I can't help much here. In fact I have no idea regarding this issue...

[Jaishankar872]

@olikraus
When I tried the ACROBOTIC_SSD1306 library display working fine. Only issue is rising while using this U8g2 library.

Refer to the post for more details & code Used.
https://community.platformio.org/t/ssd1306-display-is-not-working-on-bluepill-board-stm32f103/43752/6?u=jaishankar

Special thanks to @maxgerhardt

[maxgerhardt]

This seems to be an issue with the software-i2c implementation on STM32 in this library. It should also reproduce on a regular Bluepill board, or any official STM32 board. These glitches on the SCL and SDA lines to GND do not look good.