STM32 Oscilloscope
This week I got some inspiration from the ST DSP library, so I made my own oscilloscope with the STM32 and my 320x240 pixels QTFT screen. I made the code from scratch, both the sampling and screen updating code -- but I used the ST DSP library for the FFT calculations of course
You can see the video of the project here…
Great work, great video!
Great work using stm32. gives me some inspiration!
Thanks
How did you achived the flicker free graphics . Can you please tell me.
Flicker-free graphics?
The display is a display with a digital controller, which takes care of the v-sync. So I just write to that digital controller as a RAM, and then it remembers everything!
hi i am kannan, i saw ur video.. its really good work.. can u give any idea to use DSPs..how u used FFT results to made it to display….pls give me some idea.. this is my mail id.. kanna89ece@hotmail.com
Hi and welcome Kannan.
The FFT functions I’m using comes from ST’s DSP library, despite the fact that the STM32 isn’t a DSP, it’s a microprocessor!
In this project I use an AD port to read a number of samples, which I then use to calculate the FFT data. The FFT is kind of a spectrum showing which frequencies there are in the data!
Then you can use this FFT data and the fundamental frequency (kind of sampling frequency) to calculate the frequency there is most of.
The Fundamental Frequency is reciprocal to the sample time – this means that if you fill a buffer in 2 msec, the fundamental frequency would be 500Hz (1/0.002)
But all this are a little more complicated when using DSP’s, but the results would also be a bit better, as the chip is made for such things.
@Thomas Jespersen
thank you thomas… oh so you used microprocesor…and i understood the way u did it… so the microprocessor u use provide many DSP libraries or u download it.. i actually work on ARM controllers… will there be any DSP libraries available for ARM processors…
i thot using normal processor for DSP applications is tougher than doing it in DSPs.. how ever u hav done it using libraries… good work.. thank you.. do you know how to do power calculatons using DSPs….can you tell me abt that…?
@Kannan
ST has provided every STM32 (an Cortex-M3 ARM processor) users with an easy-to-use DSP library, and they also included great documentation and code examples.
Unfortunately I haven’t messed a lot with DSP’s yet, I have two boards from Analog Devices though – the Blackfin BF533 and another. But I haven’t tried using them for real yet!