Both links for the pump and the servo are dead. Can someone please send me a link from where I can buy them with the exact model that was used in this project. Also from the video and the schematics it's not clear to me how to connect the pump to the controller and why the two transistors. Some help will be greatly appreciated. I am basically combining two projects in one - the buzzer sound measurement and the pump and servo. My idea is to put this in from of my bedroom door and when my cat mews in the morning the sound will be detected by the buzzer and will start the water pump that will spray her :) I got the buzzer part all figured out but am struggling with the pump concept.

Hi,

You can just search for water pump on that same site, and it should get you to the item. They keep changing things around, so its hard to keep the direct link pointing to the right place. The MOSFET is there to allow you to drive the DC motor of the pump (the pump is not a servo it is a regular motor) directly from the power supply, but still control it from your MCU. This allows you to run the necessary current from your power supply to run the motor without drawing all that current from your microcontroller. Check out the motors and microcontrollers tutorial video for a more in depth explanation of driving motors with the MCU.

Humberto

You can also check hobby shops. The servos I used were from an R/C kit that I had kicking around for about 20 years or so. They are Futaba FP-S14B servos. I am not exactly using it to squirt water,it's more of a thought and hookup experiment for me but there are several ways to use something like it.