## 4 The Hardware Design and Implementation
A step motor is a brushless DC electric motor which often employed in the biomechatronics system [38]. Precise positioning control in medical devices is essential. We utilized a NEMA23 stepper motor with the configurations of; a two-phase motor with four leading wires, holding torque 1.3N.m, rated current 4A, rated voltage 3.3 VDC, external dimensions 56.4 \(\times\) 56.4 \(\times\) 56 mm, and the dual shaft dimensions are 8 mm 6.35 mm. Figure 3 shows a 3D motor model and motor's implementation. Generally, brushless motors use non-periodic movements; it breaks a full revolution into several equivalent steps; hence the step motor does not rotate but steps, the step angle of used motor is 1.8 degrees per step. 2. Regarding single driving, A 2m542 stepper driver is used to control our system's desired steps. The 2m542 driver has the specifications of; supply voltage of 24 VDC, a pulse input frequency ranged from 0 to 200 kHz, micro-steps up to 25600 steps/rev, with the implementation of a robust 32-bit Digital Signal Processing (DSP) processor. The DSP acquires the control command and converts it to the operation command of the motor. As per the motor operation commands, the DSP transmits the required signals to the drive circuit. This technology considerably enhances the stepper motor's efficiency and reduces motor's vibration, with the benefits of low noise, less current, and lower heating. Moreover, this technology can accomplish smoother motion performance at low speeds by significantly minimizing variations from the desired motor speed. 3. Moreover, mechanical limit switches, as implied by their name, limit switch are electromechanical devices. Mechanical limit switches have the advantage of high accuracy and repeatability, reliable, and low power consumption devices. We implemented two limit switches to control the worktable's mechanical functional range. The switches  
Figure 8: Hardware implementation and PCB design of the portable control unit, (**a**) front view of the hardware step-up; (**b**), back view of the portable control unit; (**c**) The serial communication (UART) between two microcontrollers: Arduino Nano (Master) TX pin, transmits the serial data including selected therapy control parameters to other Arduino Uno (Slave) RX pin which, once the therapy is executed then RX and TX pins of each Arduino vice versa send back. were engaged in controlling the travel worktable limit, to ensure that the worktable will be within the preselected fingers F/E displacement range. Concerning power management of the FWRMS's machine, we employed two power converters to supply stable voltage and the required current for different hardware components. The enter system's power supply unit includes: an AC/DC converter, which takes AC 110-260v as input, and gives 24 VDC, 51-100 W power, and 4.2 A current. This 24 VDC is used to supply the stepper motor driver and the motor. Then we implemented a DC/DC converter to supply 5 VDC was needed to supply two microcontrollers, and the rest of the electronics components. Ultimately, some tests executed on the mentioned components approve their functionality and ability to operate the proposed prototype system efficiently. Finally, the electronic component is designed and fabricated as a printed circuit board PCB. We adopted through-hole technology (THT) to prepare the final PCB through the thermal transfer method. This technology is simple and provides sustainable connectivity. It used anti-corrosion properties. After the PCB is prepared, the holes were drilled to place the electronics component then solder them as demonstrated in Figure 8a,b which also illustrate this. The portable control unit's implementation and the external dimensions of the portable control unit are 12 \(\times\) 8 cm and overall weight is 300 g.