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Can we display a test message using GPIO pins without using Graphics engine on MCU

RSHAR.2
Associate II

Hi,

I am using low end STM32L0 series MCU, I need to display a minimal text message on the TFT LCD display.

STM32L0 doesn't have LCD engine, so can we write a code with GPIOs and display a text message.

Please provide your feedback on this.

1 ACCEPTED SOLUTION

Accepted Solutions
SofLit
ST Employee

Hello,

If your converter RGB/LVDS is compatible in term of electrical characteristics: voltage levels etc .. It's ok. So you need to emulate your RGB interface with GPIO of course if you have enough GPIO pins for that.

For perf may be you have to use DMA to transfer your pre-built data (RGB) to GPIOs.

So As I said, you have to study all these elements.

Hope this will help you.

STM32

To give better visibility on the answered topics, please click on "Accept as Solution" on the reply which solved your issue or answered your question.

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6 REPLIES 6
SofLit
ST Employee

Hello,

It depends on the LCD interface you are using. If for example it has SPI interface, indeed you can easily interface it to your STM32L0.

STM32

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RSHAR.2
Associate II

Hi,

The LCD I have considered is 10inch TFT display that supports LVDS interface and I2C for touch interface.

So is it possible to drive this display with GPIO pins from the MCU with voltage levels within the display limit.

I'm asking this because using "bit bashing" can we implement this.

Please provide your comments.

Hello,

I don't think this is an optimal usage of STM32L0. You have to emulate the LVDS interface which is not obvious. May be using internal comparator?! In that case you have to study the analog part as well as the communication perf.

STM32

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RSHAR.2
Associate II

Hi,

Then I can use a RGB to LVDS convertor between STM32L0 MCU and LCD display.

If I'm using RGB to LVDS convertor to interface with LCD display, then can we configure GPIOs as RGB format (like 565 or 888) and give it to RGB to LVDS convertor and then to the display.

SofLit
ST Employee

Hello,

If your converter RGB/LVDS is compatible in term of electrical characteristics: voltage levels etc .. It's ok. So you need to emulate your RGB interface with GPIO of course if you have enough GPIO pins for that.

For perf may be you have to use DMA to transfer your pre-built data (RGB) to GPIOs.

So As I said, you have to study all these elements.

Hope this will help you.

STM32

To give better visibility on the answered topics, please click on "Accept as Solution" on the reply which solved your issue or answered your question.
TDK
Guru

I would imagine it is technically possible, but would take considerable time and be a waste of resources for any person/company who cares about their time.

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