STM32 interface with 16x2 LCD

[DJ1]

I have been trying to interface STM32F401RE development board with 16x2 LCD module. I have tried making my own driver file for the same. I tried changing LCD's twice but still the same, the issue is no data is visible on the LCD . I am working on 4-bit mode for LCD interface. I have also followed a few tutorials on the same but no change. Please do guide for the same.

[S.Ma]

Use if possible a transflexive LCD display, so you can see something even if backlight is off.

A transflexive pixel is half mirror and half backlighted.

I use the classical 16x2 character display with just GPIO bitbang a pseudo SPI to drive the display and it works ok. You can have a look at the code here.

[Tesla DeLorean]

Surely there are some working examples of driving these displays, not sure there's a lot of interest in realigning someone else's wheels.

How many tutorials are needed to re-explain the same functionality? Perhaps find a colleague, supervisor or classmate that can sit and work this through with you?

Perhaps look at Arduino, check the power/function of your display. Check with known to work schematics.

Keil, IAR and Olimex have ALL shipped boards with 4-bit 16x2 LCD displays, with code and wiring that work.

Some of the SSD130x I2C OLEDs are so much cleaner..

[Rodo]

I would suggest you start with 8-bit first. Then change it to 4-bits.

[gbm]

1. your delay routine doesn't work.
2. you must add delay between all commands
3. init sequence is incorrect

[DJ1]

Yes, i have changed a few things in this code. Please do check and let me know. The issue is if i do step by step debugging, data is coming properly but if i just simply run the code then it does not show anything on display. I thought of delay as the reason but even after increasing the delay there is no change in output.

[DJ1]

I have made a few changes and have updated the file. Please do check once!

[DJ1]

If i am doing step by step debugging, for the same code i am getting results but if i just simply run the code it does not working properly. What may be the reason? Please do share your thoughts. Already tried giving delay but that didnt work either.

[DJ1]

True but based on requirement 16x2 LCD is the best choice as of now. Have gone through several different websites and followed them but still there are issues. I have already worked with LCD's in past with Arduino and RPi but that wont be of much help in this case. I am already using STM32Cube IDE for development.