ABC Atmel AVR Mini Board LED Module

The ABC Atmel AVR Mini Board can be expanded into a very flexible development and training system using various add-on boards available. All of the ABC add-on boards are designed to be connected with the ABC Atmel AVR Mini Board via the Hotchip Motherboard Module. This pre-assembled LED module consists of eight LED's configured as two groups of four common anode sections. Each LED has a series resistor of 470 ohms to limit LED current to approximately 8.5mA when illuminated. Each LED is driven directly by an output pin of the AVR microcontroller as follows:

• cbi port,bit will turn a LED ON
• sbi port,bit will turn a LED OFF

Sinking LED's directly via an output port will result in the LED illuminating for a logic '0'. Alternatively, the LED module may be connected, via the short IDC cables, directly to the outputs of the NPN transistor module. Now, with a logic '1' applied to the transistor, the LED will light. The LED module consists of eight LED's configured as two groups of four common anode sections.  Each LED has a series resistor of 470 ohms to limit LED current to approximately 8.5mA when illuminated.