fourose.blogg.se - Raspberry pi wifi spectrum analyzer

The HT16K33 can run at 3.3 V but that was not powerful enough to light up this bi-color matrix properly. The SparkFun display is very bright but does use a bit of power. It’s a perfect match for the HT16K33 because it has 16 anodes for the 16 rows (8 red plus 8 green) and 8 cathodes for the 8 columns. If you turn both LED’s on simultaneously you get yellow too. It has 64 bi color LED’s - green and red. It will be used for the spectrum analyzer’s display. Here’s a SparkFun 2″ dual color LED matrix.

Sixteen 7 segment numeric displays which have 8 LED’s if you include the decimal.

Eight 16 segment alphanumeric LED displays.

Here are some examples of the types of displays you can use: The chip can drive 128 LED’s and it only requires 2 GPIO pins on the Pi. Check out my 7 segment LED tutorial for more information on multiplexing. It uses multiplexing to light up 8 groups of 16 LED’s. The rows connect to LED anodes and the columns connect to cathodes.

It has 16 row pins (A0 to A15) and 8 column pins (C0 to C7). This inexpensive board adds a ton of capability to the Pi and is very intuitive and easy to set up. Here’s an HT16K33 breakout board, I picked up on eBay.