# The Use of Wireless Networks and Mobile Applications in the Control of Electric Machines
## 2 Selected Wireless Transmission Technologies
In the diagram in Figure 2, there is an Arduino UNO that participates in receiving and transmitting information from the smartphone to the machine and vice versa. The Bluetooth module HC-05 is responsible for the wireless transfer of information. The temperature sensor is a block described as DS18B20, and the current measurement is performed by the ACS712-20 A system. LCT-167 PWM is a device that amplifies the PWM voltage from 0-5 V to 0-10 V whilst an external voltage supply of 12 V has been connected to the LCT-167 PWM device. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{5}{c}{**Typical for Mobile Devices**} & **Typical for IoT** \\ \hline
**Feature** & **Bluetooth** & **Wi-Fi** & **LoRaWAN** & **ZigBee** \\ \hline Bandwidth & Low & High & Very Low & Very Low \\ Hardware & Bluetooth adapter only & Wi-Fi access point and & Dedicated devices & ZigBee Condinator, ZigBee Route, \\ equipment & & Wi-Fi adapters required & & ZigBee End Device \\  & & Point-to-point, & & \\ Topology & Point-to-point & broadcast, and mesh & Star-of-stars & Star, Tree, Mesh \\  & & networking & & \\ Range & 10 m & 30–50 m in buildings, & 10–15 km & 10–100 m \\ Security & Less secure & More secure & More secure & More secure \\ Power consumption & Small power & Much more power & Very small power & Very small power consumption \\  & consumption & consumption & 169 MHz, 433 MHz, 868 & 2.4 GHz \\ Frequency & 2.4 GHz & 2.4 GHz and/or 5 GHz & MHz (Erupe) 915 MHz & 868 MHz and 915 MHz (selected \\  & & & (North America) & regions of the world) \\ Speed & Slow—about 1 Mbps & Fast—about 1 Gbps & Slow—about 50 kbps & Slow—about 40–250 kbps \\ Flexibility & Limited number of & Large number of users & Very large number & Limited number of users \\ Modulation & GFSK & OFSM or QAM & Chirp Spread Spectrum & BPSK or O-QPSK \\  & & Very popular and & Simply and easy & Simply and easy \\ Ease of use & Very popular and & widely available & Difficult access to & Simply and easy to use Difficult \\  & widely available & Complex software and & technology—it is & access to technology—it is \\  & Simply and easy to use & Hardware as well as & developed by about 500 & developed by about 150 \\  & & configuration required & companies in the world & companies in the world \\  & & & to use & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of selected parameters and features of the Wi-Fi and Bluetooth transmissions. Figure 3 depicts a control system using Wi-Fi communication module. The main element of the system is the NodeMCU-V3-1.0 microcontroller which is equipped with 10 digital outputs/inputs and 1 analogue and can be powered from an external power source or via USB. The ESP8266 module embedded in the microcontroller is responsible for wireless communication. Smartphone connects to it directly after starting the operation of Wi-Fi server or through a router. Temperature and current are measured with the same electronic circuits that are responsible for the measurements in the control system via Bluetooth (temperature-DS18B20, current-ACS712-20 [A]). The DS18B20 thermometer is connected to the digital output marked in the diagram as D4 while the ACS712 sensor is connected to the A0 analogue input. In the case of PWM voltage control, the LCT-167 PWM module is used again, and its output is connected to the D6 PIN of the microcontroller. Similarly to the previous case, the laboratory system is connected to the IP (2) (ACS712) and GND (4) (LCT-167) inputs. Figure 3: Schematic diagram of the control system using a Wi-Fi transmission module. Figure 2: Schematic diagram of the control system using a Bluetooth transmission module.