Voltage Sensor Dc0-25v for Arduino with Code(Pack of 2pcs)

Fairly accurate (+/- 0.10v). It's hard to find anything on the net about this sensor if you are new to Arduino. But after searching the interwebs, and experimenting, this is my final result on an Arduino UNO:- pin hooks to ground+ pin not useds pin hooked to pin A0 (Analog 0)Then I tinkered with the following code:int analogInput = A0; //Change if not connected to pin A0float vout = 0.0; //do not changefloat vin = 0.0; //do not changefloat R1 = 30000.0; //onboard resistor 1 valuefloat R2 = 7500.0; //onboard resistor 2 valueint svalue = 0; //do not changevoid setup(){pinMode(analogInput, INPUT);Serial.begin(9600);}void loop(){svalue = analogRead(analogInput); //this reads the value from the sensorvout = (svalue * 5.0) / 1024.0;vin = vout / (R2/(R1+R2));Serial.print(vin,2); // prints the voltageSerial.println(" volts DC"); // prints the words "volts DC"delay(1000); //delay loop for 1 sec}This code will give you results in the serial monitor. Make sure to set your baud to 9600.I haven't figured out how to calibrate the module yet. I'm assuming I'll just add or subtract some from the vin variable depending on which way I the sensor is off.Hope this helps anyone else out there,

The are ok and somewhat accurate.

I bought this for one of my first Arduino designs. As part of my first program it works great.

These are good voltage sensors. Easy to use and seem to be reliable.

And the internal voltage varies.If you use your Arduino only for voltage measurements, and your power supply is stable, you will get consistent results. However, if you do anything which requires output the results can be quite unreliable. I am controlling a small relay (one of the blue ones you see from a dozen different Amazon sellers). Just turning the relay on and off changes a voltage reading of 13.06 V to 13.33 V. The error of 0.27 V is 55 times bigger than the claimed precision!Yes, precision is not accuracy, but this was still a bit of a shock. To be clear, the relay's power output is NOT drawing anything from the Arduino. Just switching the relay creates this effect.As you can see in the code from BikerBud (thank you for that!), any error in reference voltage is multiplied by 5. In my case the bottom-line error of 0.27V would have been caused by just a 0.054 drop in voltage on the Arduino.I plan to solve this by using an LM4040-based voltage reference and comparing the two voltages. My mistake for not looking at this product more carefully. It doesn't "sense" voltage. It's just a voltage divider which relies on the Arduino to do the voltage comparison.

I like it so much

works as described, accurate enough for battery low voltage sensor.

Easy to use with Raspberry via ADC but for need for programmatical corrections. Now, I can collect real time measures of voltage with decent accuracy while collecting multiple sensory data.