Another idiot walks into the arena here so thanks for your patients, thanks for taking a look.
i am planning to build a circuit to switch between resistors in a resistance ladder and was hoping to control it via arduino board. the specified reference voltage for the circuit is 5 volts and +/-5% tolerance for the resistance. So the plan is to connect the resistors to the digital pins and switch on/off through an arduino.
I've noticed that the voltage on the digital pins is 4.81v so am i already 0.2v down and was wondering about any resistance from using the arduino?
I Tried (don't laugh here!) to read the resistance in circuit when the arduino switches but of course.................doh!
The other option i was thinking is a darlington array or a load of transistors to switch the circuit but i'm not sure about any voltage drops or internal resistances.
thanks in advance...
i am planning to build a circuit to switch between resistors in a resistance ladder and was hoping to control it via arduino board. the specified reference voltage for the circuit is 5 volts and +/-5% tolerance for the resistance. So the plan is to connect the resistors to the digital pins and switch on/off through an arduino.
I've noticed that the voltage on the digital pins is 4.81v so am i already 0.2v down and was wondering about any resistance from using the arduino?
I Tried (don't laugh here!) to read the resistance in circuit when the arduino switches but of course.................doh!
The other option i was thinking is a darlington array or a load of transistors to switch the circuit but i'm not sure about any voltage drops or internal resistances.
thanks in advance...