This paper deals with open loop speed control of Brushless DC motor (BLDC) using Arduino UNO processor. Real-time implementation of the drive in open loop speed control has been performed in which speed of the motor depends on the input voltage given to the stator winding and it is nothing but duty cycle setting. The open loop speed control is also useful in many practical applications however, the present work mainly deals with studying the running performance of the drive without using any speed feedback arrangement. That means, the speed of the motor may vary when it is subjected to load variations and/or supply voltage variations. The validity of the proposed approach is proven through experimentation on BLDC motor using low cost Arduino UNO processor. Speed Control of BLDC motor using other microcontroller requires more hardware and increases the cost, and the availability of Arduino with versatile features motivated to develop a cost effective and reliable control with variable speed range. In the present work, an algorithm which uses the Hall sensor signals acquired from the motor is developed and the program has been written using Arduino. This program generates the firing pulses required to drive the MOSFETs of three phase fully controlled bridge converter driven by IR2101 FET drivers. Later the program which has been dumped on the Arduino and tested with the 24 V, 80 W, 1500 rpm BLDC motor which can make the motor run at constant speed ranging from 6 to 1500 rpm. The proposed hardware and the program are found to be efficient and the results are promising.