i s f r i b g b

Displaying various colour combinations using RGB LEDs without a microcontroller has certain limitations. The circuit presented here can produce 255×255×255 different colour combinations using a single RGB LED. The colours can be selected by entering the values for red, green and blue using the keypad. matrix wired with the MCU board DV VKRZn Ln WKH figXUH. (DFK VZLWFK KDV EHHn DVVLgnHG D VSHFLfiF nXPEHU (value) as shown in the table.

The MCU and LCD female connHFWRU (C211) LV DYDLlDElH Rn WKH .n6 board itself. The LCD is connected to the board using a 16-pin male connHFWRU (C212) WKDW LV VRlGHUHG Rn WKH LCD. The supply and contrast input WR WKH /CD LV fixHG Ln WKH ERDUG EXW also provided through the MCU board.

The software is written in ‘ C’ language and compiled using hEIL version 4.0 demo platform. Steps to burn the program in the chip are very simple and mentioned in the manual of EFY-hnS 8051 development board.

The working of the circuit is simple. When you reset the system, it asks yRX WR fiUVW HnWHU WKH YDlXH IRU ‘UHG’ through the LCD. Any number between 0 and 255 can be entered, which will affect the intensity of ‘red’ in the finDl FRlRXU FRPELnDWLRn. 6LPLlDUly, WKH values for green and blue are asked. 2nFH Dll WKH WKUHH YDlXHV DUH HnWHUHG, the LED shows a colour combination corresponding to the values entered.

To produce only red colour, you can enter 255 for red and 000 for green and blue.

Assemble the circuit on two separate general-purpose PCBs—one for 3×4 matrix keyboard and the other for the RGB LED. Connect the keyboard matrix, LCD and LED1 to the EFY-hnS 8051 development board as shown in WKH figXUH.