Drip irrigation systems are one of the most efficient irrigation systems in water use. Drip irrigation systems in plantation areas with different types of plants have different watering times, so the water pressure in the pipe varies according to the number of activated emitters. The unstable water pressure in a pipe will make the water flow at the emitter output unstable, so that the volume of water supplied to the plant is unstable as well. Therefore, it is necessary to control the water pressure in the pipe and keep it constant. Pressure control is conducted by adjusting the speed of the water pump. This research focused on implementation of water pressure control on a drip irrigation system using a centrifugal water pump driven by a brushless DC motor. This study uses a sectrifugal water pump with a maximum discharge capacity of 26 l/h and the maximum head is 15 meters. This water pressure control system has a feedback signal from a water pressure sensor mounted on the irrigation network pipe. The proportional integral control method was implemented on an ARM microcontroller with a sampling time of 100 ms. The controller parameters were calculated using the Ziegler and Nichols methods that yield proportional and integral constants of 0.5 and 4.9 respectively. The prototype testing was performed by providing a set point of water pressure control at 14 psi, in which the system has a rise time of 3 seconds and a steady state error of 3.6%.