wireless monitoring system of gas detector - Faculty of Electrical ...

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After interfacing the data transfer and LABVIEW was done, the next process is
to read the data transfer. From the figure 3.24, decimal string to number is needed for
converting the numeris characters in string thats starting at offset to a decimal interger
and return it in number. Once the string number from visa has been changed, the output
number needs to convert back into the original of voltage value. The converter process is
shown in Figure 3.25. As mentioned before, Arduino will read the data in the 10-bit data
only. Therefore, to convert the value in the original voltage is by the equation in 3.7.
Figure 3.25: Converter Process
The next step in LABVIEW process is to show the LED indicators for user
monitoring. The range will conduct the voltage value according to the threshold value
that has been set before.
Finally, the last step is to monitor the concentration value of the gas. In this step,
the concentration value is calculate based on the graph analysis as mentioned before.
Therefore, to calculate the gas concentration for LPG and alcohol gas are using the
equation 3.8 and 3.9 as below.