Chronic pain, which includes back pain, headache, and joint pain, affects one out of three people worldwide. The work, social life, and mind of an individual who suffers from this illness can be affected, and the illness severe. A transcutaneous electrical nerve stimulation (TENS) device is typically used to relieve the pain. Existing TENS devices, however, consist of a hard-coded program and are unhandy. Therefore, this work aims to improve such devices by using Arduino to make them programmable and handy. Arduino can be programmed to produce an electrical pulse pattern desired by the user. The circuit is equipped with Bluetooth to make it handy and connect it to a smartphone application. Results indicate that Arduino can generate electrical pulses similar to existing TENS devices and can be easily changed if required. Thus, it provides patients with customized treatment patterns and is portable.