Mega2560 with voltage divider problem (Closed)
Posted: Wed Jul 17, 2019 11:47 am
The Mega2560 ADC input A3 draws apprx 80mA of current when the voltage divider is connected.
Voltage divider works OK without being connected to Mega2560 ADC input A3.
...
When the voltage divider is connected to A3 input the voltage drops from (say) 0.3v to 0.03v.
I found out that Arduino ADC input has the pull-up resistor and when this resistor
is connected (by default?) it sinks the current.
----
Solution: the ADC An0 input should be connected to F3.
Voltage divider works OK without being connected to Mega2560 ADC input A3.
...
When the voltage divider is connected to A3 input the voltage drops from (say) 0.3v to 0.03v.
I found out that Arduino ADC input has the pull-up resistor and when this resistor
is connected (by default?) it sinks the current.
----
Solution: the ADC An0 input should be connected to F3.