K1
TWI Position
TWI
SPI
K1
SPI Position
TWI
SPI
3.6 On-board Resources
3.6.1
Description of LED Bank
The AT88Microbase includes 3 general purpose red LEDs, which are connected to PD6, PD5 and
PD4. To light an LED, the corresponding port pin must be driven high. To turn off an LED, the
corresponding port pin must be driven low.
Figure 8. LEDs Implementation Schematic
Note: AVR can source or sink enough current to drive an LED directly.
3.6.2
Buzzer
The small onboard buzzer adds audio capability to the AT88Microbase board. The buzzer requires
that PD7 be driven with a square wave at 4.0 0.5 KHz to achieve a maximum decibel of 78dB.