Post on 17-Dec-2015
Asuro Switches/Interrup behaviour
The Asuro Atmega8L is initialized in such a waythat switch interrupts are detected as long as theinterrupt detection pin (Pin 5, PD3) is at a low level.
...when using interrupt todetect a switch press.
Switch K1
Pin5 = I/L
High level by R23,1MOhm to VCC
Switch K1
Pin5 = I/L
Switch K1is pressed
High level by R23,1MOhm to VCC
Switch K1
Pin5 = I/L
Switch K1is pressed
High level by R23,1MOhm to VCC
External interruptlow level reached
Switch K1
Pin5 = I/L
Switch K1is pressed
High level by R23,1MOhm to VCC
External interruptlow level reached
Pin5=O/H
Switch K1
Pin5 = I/L
Interrupt functionstarts execution
Switch K1is pressed
High level by R23,1MOhm to VCC
External interruptlow level reached
Pin5=O/H
Switch K1pressed,stable level
Switch K1
Pin5 = I/L
Switch K1
Switch K1pressedstable level
Switch K1is pressed
Switch K2
Switch K2pressedstable level
Switch K2is pressed
Switch K3
Switch K3pressedstable level
Switch K3is pressed
Switch K4
Switch K4pressedstable levelSwitch K4
is pressed
Switch K5
Switch K5pressedstable levelSwitch K5
is pressed
Switch K6
Switch K6pressedstable level
Switch K6is pressed
Switch K1is pressed Switch K1
pressedstable level
6ms delay
Start ADCmeasurement ADC
measurementfinished,Pin5=I/H
Switch K1still pressed
Switch K1
an arbitrary delay
Switch K3is pressed
Switch K3pressedstable level
6ms delay
Switch K3still pressed
Pin5=I/L Pin5=O/H
Switch K3pressedstable level
Switch K3
Switchinterruptenabled
Switchinterruptdisabled
Time neededby programto handle interrupt
New interrupt.Interrupt generatedwhen low level.
Switch K3
Pin5=I/L
Switch K3released
High level by R23,1MOhm to VCC
Switch K1
Switch K3pressedstable level
6ms delay 6ms delay
Pin5=O/H
Switch K3released
Start ADCmeasurement
Wrong valuemeasurement
Sometimes a wrong value can be measured.