Does MQ 5 need AD conversion to communicate with a microcontroller after collecting data?

Yes, AD conversion is required to convert the analog signal of the sensor into a digital signal.

Detail. The gas-sensitive material used in the MQ-5 combustible gas sensor is tin dioxide (SNO2), which has low conductivity in clean air. When combustible gas is present in the environment in which the gas sensor is located, the conductivity of the combustible gas sensor increases with the increase of the concentration of combustible gas in the air.

A simple circuit can be used to convert the change in conductivity into an output signal corresponding to the concentration of the gas.

The MQ-5 combustible gas sensor has high sensitivity to butane, propane and methane, and can take into account both methane and propane. This gas sensor can detect a wide range of flammable gases, especially natural gas, making it a low-cost sensor for a wide range of applications. Through AD conversion, the single-chip microcomputer can process it.

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1, What is AD conversion?

A is the meaning of analog signal, D is the meaning of digital signal, AD conversion is analog-to-digital conversion, as the name suggests, is to convert analog signal into digital signal, such as converting voltage value into digital signal.

2, Why do you want to convert AD?

Single-chip microcomputer (and other processors) can only process digital signals, when the single-chip microcomputer wants to obtain the voltage value of a certain point on the circuit, it has to use AD conversion, if you directly connect the pins of the single-chip microcomputer to the point of the circuit, the single-chip microcomputer only knows whether the voltage at this point is low or high, and how can you get his voltage value? For example, when the digital multimeter measures the voltage, there is an AD conversion circuit to convert the voltage value into a numerical value, and then send this value to a single-chip microcomputer (of course, the processing chip used in the multimeter is not a single-chip microcomputer), and the single-chip microcomputer is calculated and processed, and then the voltage value is displayed on the screen.

However, there are some relatively strong microcontrollers, which have integrated AD converters inside, and you don't need to connect external AD conversion chips.

What does 3,8-bit 16-bit AD converter chip mean?

8 bits, 16 bits represent the conversion resolution of the AD conversion chip, the larger the number, the higher the resolution, but also reflects its accuracy, the larger the number, the higher the accuracy is relatively high. 8 bits is the lowest, and the AD converter integrated in some microcontrollers is generally 10 bits. 12-bit and 16-bit chips** are more expensive.

4. Resolution?

For a simple example, the 8-bit chip can only convert the minimum voltage, while the 12-bit chip can convert the minimum voltage, if a voltage is, the value of the 8-bit chip is converted out, and the 12-bit chip is converted out, and the accuracy is one grade higher than that of the 8-bit. (Note: The value here is not the correct value, for example, do not actually use).

5. Sampling? Sampling is the speed performance index of AD conversion, in layman's terms, how many times can be sampled per second, and the higher the number of samples, the better the chip performance. If you don't understand sampling, you can also understand it in another way, which is the time required for the process of converting the voltage value into a digital value by an AD converter, the shorter the better.

6. Accuracy? Accuracy is an important parameter of the AD chip, indicating the degree of difference between the collected data and the true value. For example, the result of the single-chip microcomputer conversion is, and the actual result may be, so the difference. This error is inevitable and cannot be eliminated.

This is related to the number of digits mentioned in point 3, the higher the number of digits, the smaller the error.