I was following the official tutorial of LED matrix integration and couldn't figure out why there is no resistor.
I assumed there are built-in resistors in the LED matrix, so I did an experiment by connecting pin 9 of the LED matrix to v5 of my Arduino Leonardo board and pin 13 of the LED matrix to GND of the same board. You can refer to the schematic diagram below to know I was trying to lit up the LED at the position [0, 0].
Unfortunately, the LED next to [0, 0] burned immediately and I still couldn't figured out it.
- Are resistors necessary for 8x8 LED matrix?
- If yes, why the official example doesn't have any resistor?
- If no, why my experiment failed?
- If no, why are there so many unofficial examples use resistors for each wire?