3.4 Experimental analysis
(1) draw the experimental schematics: According to the design idea, you can draw the experimental schematics, which is shown in Figure 3-3, and this principle of LM35 is the same as Section 8 from the Basic Part. To readers’ convenience, this figure is given here again. Compared with this experiment, it is short of Arduino shield board and wifi board. But the principle of collecting temperature by LM35 is the same as Section eight in the Basic Part.
Figure 3-3 experimental principle
(2) circuit connection: By the experimental principle, we firstly connect the circuit shown in Figure 3-4.
Figure 3-4 Experimental connection
(3) wifi network connection: when we power the wifi on the Arduino main board, we can get the wifi signal. But, note that, for the stability of wifi signal, we should power the wifi shield board by the 15V voltage adapter designed in Table 3-1. Then, after a short while, you can search a wifi signal in your compter named as HI_LINK_XXXX (which is said in Section 2) transmitted by wifi module. Here, in my computer, the wifi signal is called as HI_LINK_0021. Then double click the wifi network HI_LINK_0021wifi, and input the password ( the default password is 12345678). It is said that you have connected the wifi networks. Note that, if you use the wifi module at the first time, to ensure the exactness of data configuration, wifi module needs to recovery the default factory settings (press the button RST on the Arduino shield board for 6 seconds, then power off and reboot for the wifi module. Also can see the method in Section 2). This step is similar to open the wifi in our phone to surf the internet. It shows that the wifi module can transmit the wifi signal. Then, if wifi module connects a wifi hot spot, then we can let data send by wifi communication.