and I want to add LED indicators connected to INPUT pin and GND, surely I connect LED with a series resistor which leads to voltage drop so basically arduino sends to driver 3 volts instead of 5.
So my question how I can safely add LED indicator to see which input is triggered but avoid voltage drop.
Your input pin will still see 5v as the potential difference between the pin and the input pin is 5v irrespective of what goes on in between the arduino and the input pin.
Without the series resistor you would overload the pin and pull it well below
5V. The series resistor takes up the difference between led voltage and 5V and
so long as you don't pull too much current from the pin it will be fine.
Your circuit shows the motor power going through the voltage regulator - that's
not a good idea - have the motor supply direct from the battery.
calvingloster:
Your input pin will still see 5v as the potential difference between the pin and the input pin is 5v irrespective of what goes on in between the arduino and the input pin.
So you say that even if I put a led with resistor the pin on l293d driver will see incoming voltage as 5 volts? But when I test it with multimeter it shows me that voltages is ~3.2V
MarkT:
Without the series resistor you would overload the pin and pull it well below
5V. The series resistor takes up the difference between led voltage and 5V and
so long as you don't pull too much current from the pin it will be fine.
Your circuit shows the motor power going through the voltage regulator - that's
not a good idea - have the motor supply direct from the battery.
yeh, but how can I achieve my goal, maybe there is some other way to connect led indicator so original destination still receives 5V and LED is regulated with a resistor?
Look at this pic. You can place the LED in two ways. One way, it lights up when the output of the Arduino is "High" and the other, it will light when it is "Low"
Zapro:
Look at this pic. You can place the LED in two ways. One way, it lights up when the output of the Arduino is "High" and the other, it will light when it is "Low"
// Per.
I want to trigger LED when voltage is HIGH and this is exactly what I already tried, but connecting LED with series resistor like this reduces input voltage to driver input pin from 5V to 3V because of the series resistor, so I feel that this is not the best way to approach.
Or you trying to say that it doesn't matter that I have voltage drop? Sorry I still confused about this...
endryha:
I want to trigger LED when voltage is HIGH and this is exactly what I already tried, but connecting LED with series resistor like this reduces input voltage to driver input pin from 5V to 3V because of the series resistor, so I feel that this is not the best way to approach.
Or you trying to say that it doesn't matter that I have voltage drop? Sorry I still confused about this...
If your output signal drop to 3 volts, there are 2 possibilities. Either you are using too low a resistance or no at all, and the LED "shunts" the voltage heavily, which will eventually break your Arduino.
Otherwise, you have the resistor placed incorrectly. Look at my drawing attached.
