The LedBorg provides a tri-colour LED controllable from the Raspberry Pis GPIO header. Using simple on / off logic it can provide a total of seven colours as well as off. Using software based pulse width modulation (PWM) it is capable of many more colours, around a million in fact.
The LedBorg uses the following GPIO pins:
|RPi pin||WiringPi pin||LedBorg use|
|GPIO 27 (21 on rev1)||2|
|5v (power)||Power for the LEDs|
The on board chip converts the 3.3V logic level signals used by the Raspberry Pi into the 5V levels used by the LEDs. On the revision 1 Raspberry Pi GPIO 21 is used instead of GPIO 27 due to the header change, see here for more details. A HIGH logic level (also known as 1 or ON) on one of the GPIO pins connected to an LED colour enables that colour channel of the LED. A LOW logic level (also known as 0 or OFF) on one of the GPIO pins connected to an LED colour disables that colour channel of the LED. The extended range of colours is produced by varying the channel between these high and low states quickly, which in turn dims the channel.
The board layout on LedBorg allows for the proper amount of heatsinking to keep the board cool from the heat generated by the LED. A decoupling capacitor is connected to the 5V rail near the chip, this means live plugging/unplugging is not recommended as it may reset the Raspberry Pi when doing so. The LED is an AVAGO ASMT-YTC2-0AA02 with the following specifications: Red 450mcd/629nm, Green 560mcd/521nm, Blue 180mcd/464nm 120 degree viewing angle The full schematic for LedBorg is available here.
The LedBorg is approximately L35.5mm x W16.5mm x H11.5mm in size and fits inside a lot of available Raspberry Pi cases.
- Light your case in a different colour when your mood changes - can display around a million colours using PWM!
- Use the LED as a status display such as a resource monitor.
- Program mood lighting from your Pi.
Software included has a colour selection GUI, demo sequence function, example code - Open Source code
Click here for instructions, installations and source
RGB LED with software programmable intensity levels