Am i over thinking things ?

Hi all, i'm assembling a project and with the little seat time i have i wanted to run this pass anyone for advice cause i may be doing too much.

I want to control 7 leds thru wireless. I'm building my board now and here's what i feel i need.... 1.328p 2.MCP23008 3.UNL2003A 4.Nordic 2.4 module/board I figured i'd use the MCP23008 to save pins for the Nordic and future stuff and the UNL2003A to provide power for the leds. am i on the right road or is there a better way to do this. the things listed above are only for the reciever board. Thanks in advance for any input.

The wireless uses SPI, so as long as you don't intend to run it off the MCP23008, it should be fine. Connecting the LED's is up to you, should be enough free pins to use a transistor setup, or that 2003 chip will probably do too.

If your app runs too slow, there are many things you can learn to improve the code.

If you use that combination of chips for the LEDs you need 2 chips and a resistor per LED. Chips like the TLC5916 will do the LED driving with a single resistor and probably be ok for your normal IO as well. Whether or not you wind up with fewer chips depends on the number of IO pins you need but at least you'll lose the current limiting resistors on every LED.


I’m not sure i have a tlc5916 on deck but this should be a uphill battle with the programming i just finished wiring the leds and resistors, it was the only thing i was sure of i do have most everything to complete so i’m gonna keep at it with a few pics here and there. then off to programming