Monthly Archive: January 2015

Library 51- Chrom-ART Accelerator (DMA2D) graphic library on STM32F429-Discovery 11

Library 51- Chrom-ART Accelerator (DMA2D) graphic library on STM32F429-Discovery

ST’s Chrom-ARTTM Accelerator function or DMA2D is supported in this library. This is powerful tool in STM32F429/39 or STM32F427/29 devices. It is based on DMA transmission from graphic to memory in top possible speed. This can be used to draw moving objects, rectangles, circles very fast without a lot of work. My DMA2D GRAPHIC library was designed in a way that can support any LCD. Because anything that DMA2D knows is writing “data” (color) in memory at some locations. You...

How to properly set clock speed for STM32F4xx devices 65

How to properly set clock speed for STM32F4xx devices

I see that you have problems with your devices when you don’t know even (and you don’t even ask) on which speed your device is actually running. Speed of your device depends on PLL settings or clock source you have selected for system core clock. In most cases system core clock’s source is┬áPLL output. To get proper value, you check ALWAYS first these settings when something is not working. Because I’m tired of questions that something is not working but...

STemWin on STM32F429-Discovery board 77

Library 50- STemWin for STM32F429-Discovery

ST provides emWin library from Segger. It is professional GUI (Graphical User Interface), optimized for speed and performance for microcontrollers. ST has it’s own implementation, called STemWin. With this GUI, you can do many thing, of use simple buttons, dialogs, text boxes, to playing videos, displaying pictures, menus, etc. I suggest you that you go to segger’s website and read more about this very useful tool. In my library, I’ve some changes from original ST’s example for STM32F429-Discovery board, because...

Locked OTP Bytes 1

Library 49- One-Time programmable (OTP) bytes on STM32F4

STm32F4xx devices have OTP (One-Time-Programmable) bytes. They can be used for permanent store of configuration data for your device. Bytes are structured in 16 data blocks where each block has 32 data bytes of available memory. There is also 17th block with 16 bytes of data. His “work” is to store information about states of data block, because you can lock each block forever even if it is totally empty. Important notes: When you write data to specific OTP location...

PWM graph 46

Library 48- Measure PWM input signal with STM32F4

First library in 2015 is here. With it, you will be able to measure PWM input signal from “other world”. STM32F4’s timers have capability to make an interrupt on edge, when signal is active on input pin for specific timer. This allows us, to measure signal in input. With a simple calculations, we can detect frequency of signal and duty cycle. Of course, this is not veery accurate, but with 168MHz F407 device, using 32bit TIM2 (high resolution) I got...