Sensor wiring issues

乐乐老了

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I would like to ask which port of the microcontroller should be connected to the signal output port of the sensor shown in the figure above

乐乐老了

The output is a voltage signal between 0-5V, but the microcontroller is 3.3V. Do I need to add a step-down module?

chunyang

Connect to the ADC input port, preferably through an op amp buffer.

chunyang

LeLeLao posted on 2020-8-18 08:48 The output is a voltage signal, between 0-5V, but the microcontroller is 3.3.V. Do I need to add a step-down module?

Using resistors to divide the voltage has nothing to do with the step-down module.

chunyang

It is best to check the manual of the sensor, it may be possible to connect it directly to the 3V system.

乐乐老了

chunyang posted on 2020-8-18 15:53 It is best to read the manual of the sensor. It may be possible to connect it directly to the 3V system.

Moderator, please check if this is the way to draw it.

chunyang

LeLeLao posted on 2020-8-18 16:47 Moderator, please take a look and see if it is drawn like this

The voltage-dividing connection method is like this, and you can calculate the resistance value yourself. However, for this special case, it is probably not necessary to be so troublesome. Reducing the resistance value of R2 in the main post may be enough. You need to check the device manual to confirm.

chunyang

Even if the sensor does not support 3V direct output, then R2 can be changed to two resistors in series. The total resistance value remains unchanged, but the voltage division is still 3V. So, hurry up and read the device manual, and use one less component.