So I am trying to power an arduino to measure water flow. It works all fine and dandy when I am powering it with laptop, but when I directly power it with 12V 1.5A adaptor the readings take a second to come to the LCD even though the pump starts running. Also when they come, I can see that sometimes it hangs. Why is that?

Before taking the readings I am switching on a motor which is also directly powered by the adaptor just like the arduino.

Below is a block diagram.

Would adding a voltage regulator that steps down 12V to 9v between arduino and adaptor help?

So I am trying to power an arduino to measure water flow. It works all fine and dandy when I am powering it with laptop, but when I directly power it with 12V 1.5A adaptor the readings take a second to come to the LCD even though the pump starts running. Also when they come, I can see that sometimes it hangs. Why is that?

Before taking the readings I am switching on a motor which is also directly powered by the adaptor just like the arduino.

Below is a block diagram.

Would adding a voltage regulator that steps down 12V to 9v between arduino and adaptor help?

So I am trying to power an arduino to measure water flow. It works all fine and dandy when I am powering it with laptop, but when I directly power it with 12V 1.5A adaptor the readings take a second to come to the LCD even though the pump starts running. Also when they come, I can see that sometimes it hangs. Why is that?

Before taking the readings I am switching on a motor which is also directly powered by the adaptor just like the arduino.

Below is a block diagram.

Would adding a voltage regulator that steps down 12V to 9v between arduino and adaptor help?

So I am trying to power an arduino to measure water flow. It works all fine and dandy when I am powering it with laptop, but when I directly power it with 12V 1.5A adaptor the readings take a second to come to the LCD even though the pump starts running. Also when they come, I can see that sometimes it hangs. Why is that?

Before taking the readings I am switching on a motor which is also directly powered by the adaptor just like the arduino.

Below is a block diagram.

Would adding a voltage regulator that steps down 12V to 9v between arduino and adaptor help?