Introduction

A cheap RGB to VGA adapter. You can make STM32 (or other MCU/MPU with LTDC controller) directly drive standard VGA display devices (not limited to monitors, but also TVs, projectors, etc.). Solve the problem of MCU screen not being big enough, not cool enough, not beautiful enough at once. Supports the RGB screen interface of Punctual Atom and Wildfire.

characteristic

• Very cheap. The only original components required are a bunch of resistors and capacitors, an LDO (can be omitted), an interface protection chip (you can omit it if you think your MCU head is strong enough to challenge unexpected ESD), and two FPC sockets (if If you only have Wildfire or Punctual Atomic, you can only solder an FPC socket and save 50 cents) and a standard VGA male connector (just remove it from the old motherboard)
• RGB interface compatible with Punctual Atomic and Wildfire
• It can even be used as an RGB interface adapter board for Atomic and Wildfire
• The size is the same as the Wildfire F429V1 core board (first of all, I don’t recommend this board) and can be easily installed.
• RGB565 standard, 65K color display
• Spare pads are left to facilitate series resistors to obtain the required resistance value.

Instructions

0: Prepare

Please make sure you understand the timing of the RGB interface protocol and the timing of the VGA interface protocol. If you don’t understand, please refer to this video: [Bilingual] This may be the worst graphics card in the world - Bilibili Animation

1: Determine resolution and refresh rate

Select a resolution and refresh rate you want to output from this web page VGA Signal Timing . This needs to be based on your MCU performance, memory size and monitor support. For example, STM32 supports up to XGA resolution. In addition, a high refresh rate will greatly occupy the bus resources of the MCU, causing the speed of the MCU to run other codes to seriously decrease. The recommended resolution here is 800x600@60Hz. After testing, STM32F429 with this resolution can be driven normally.

2: Obtain timing

After determining the resolution and refresh rate, we click on the corresponding link, which contains the corresponding timing:

3: Set the timing of the MCU's LTDC controller

Here we take STM32F429 as an example. It is recommended to use CubeMX, which can make this work much easier. First, set the frequency of the LTDC controller to the Pixel freq of the VGA signal timing

Continue to set the timing parameters of LTDC according to the selected VGA signal timing parameters:

4: Done

Generate a corresponding project based on the Pinout relationship of your board, or write down the parameters and modify your code manually. Burn program. Then connect the module to your development board and you're done!

5: If you still can’t

There is a demo project in the attachment, which is adapted to the Wildfire F429V1 core board. Take it and use it.

Picture appreciation

Empty board

Welded finished product

Punctual Atomic F767 core board successfully driven

800x600@60Hz

Used as an adapter board for Punctual Atom and Wildfire Screen

The screen in the picture is atomic. After using this module to transfer it, it can be used on Yehuo's development board.

Show picture effect

The development board is installed under the module, and the model is Wildfire F429V1 (again, this model is not recommended)