Another cool buy that I’ve found on eBay is a 8×8 LED matrix powered by the MAX7219 (Example: http://goo.gl/lkyY4c). Its really easy to interface and uses SPI which I’m beginning to think is my favourite protocol!
The STM32F0 is a pretty high quality processor based on the ARM Cortex M0 and doing a simple 8 point DFT isn’t particularly hard.
To some people reading the code, it might seem a bit odd how I’ve programmed the rows and columns, the only reason for this was so I could insert the 8×8 LED board directly into my breadboard, hence the rows and columns were changed to fit the orientation.
The MAX7219 chip (http://goo.gl/rkt1VB) has a 16 level brightness controller and in the program, I mapped the average intensity to brightness so when really large peaks hit, the brightness of the screen increases. This was really easy and was just a filtered version of the sum of all the 8 DFT bands. The sample rate is 48kHz and the bands are spread pretty evenly throughout the frequency range. The input signal is merely windowed with a rectangular function which might explain the presence of so much low end (though it was a dubstep song!)
I recorded a quick video too!
As with all my other posts so far, once I figure out github, I’ll upload the code.
Can you sent your code for me? Thanks you!
Can you sent project for me? Thanks you very much!
Can you send your project for me?..Tks
I’ve been meaning to rewrite this but I don’t have a 3.5mm cable with me back at home so this one will have to wait a couple of weeks, sorry!
I need it, you can send the code matrix LED display. thank you very much. 😀
Hi Hoang,
I’ll be redoing this post exams (towards the end of January).
Thanks,
Harris
thanks you very much. 😀