A LED driver is an electrical device that regulates the power to an LED or string(s) of LEDs. What makes a driver different from conventional power supplies is that an LED driver responds to the ever-changing needs of the LED, or circuit of LEDs, by supplying a constant amount of power to the LED as its electrical properties change with temperature.
Think of an LED driver as ‘Cruise Control’ (like in a car) for the LED, and the temperature changes of the LED are the hills and valleys it is ‘driving’ over. The power level (or ‘Speed’) of the LED is maintained constant by the driver as the electrical properties change (amount of ‘gas’ or power needed) throughout the temperature increases and decreases (or ‘hills and valleys’) seen by the LED(s). Without the proper driver, the LED may become too hot (driving too fast) and become unstable (out of control), causing poor performance (engine problems) or complete failure (crash!)
Led driver is one of the most requested things to do. I think it's because leds are getting gradual maturity according to current LED technology,if you take care,not difficult to find suitable item for your requirements (CCT,CRI), but for the LED driver, it is a key factors to affect the complete lamp life.
Here we going to present how to interface a Sure Electronics HT1632-based led-matrix module to a any Netduino, although I strongly recommend to consider the Netduino Plus) 2, due the major resources availability.
Each led-matrix module is composed by 32x16 bi-color leds, which can light green and/or red. By mixing both the colors, the dot appears as bright orange. Unfortunately, there's no ability to dim every single led. Physically, the board ships with four HT1632 controllers, each one drives two 8x8 bi-color led-matrix module.
The module itself is very well designed and also relatively simple to interface to any microcontroller, because its SPI-like protocol require no particular complexity to implement. However, the HT1632 led controller requires a 12-bit data format, which is not natively available as "pure-SPI" on many MCUs. The STM32 is one of them!
Finally, it's worthwhile noting that the module embeds a little logic for addressing the HT1632 chips. The Sure engineers found a very smart way for addressing a cascade of controllers, so that many modules can be pipelined without any pain. However, at the moment of writing this, the driver is tailored for just one module (i.e. no pipeline supported).
As a personal consideration, several Sure modules can be accustomed horizontally, for a perfect long striped matrix. However, the tall PCB yields hard time for a vertical extension of the matrix.