I am finding some strange values when reading the voltage of my fc22 load cell (http://www.mouser.com/ds/2/418/FC22-710706.pdf) using my Arduino Nano. I'm using the milivolt version of the sensor.
I have done the following:
Connect the input of the sensor to the 5V power of the Arduino, which is actually 4.8V according to my cheap multimeter.
Measure the output of the sensor using my multimeter, I get readings in the order of a couple of mV, which is correct according to the datasheet.
Measuring the output of the sensor using the Arduino I get values of around 417, which is around 2V.
Which FC22? Full part number? Nano has a reverse blocking diode (Schottky) so voltage 0.3 less than VUSB is normal. Post the program you are using to read the load cell.
The full part number is: FC2211-0000-0100-L, which means it is the 100lbf version, with an output of 20mV/V output.
The program that I'm using is the standard voltage program that can be found on the website:
/*
ReadAnalogVoltage
Reads an analog input on pin 0, converts it to voltage, and prints the result to the serial monitor.
Graphical representation is available using serial plotter (Tools > Serial Plotter menu)
Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.
This example code is in the public domain.
*/
// the setup routine runs once when you press reset:
void setup() {
// initialize serial communication at 9600 bits per second:
Serial.begin(9600);
}
// the loop routine runs over and over again forever:
void loop() {
// read the input on analog pin 0:
int sensorValue = analogRead(A0);
// Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V):
float voltage = sensorValue * (5.0 / 1023.0);
// print out the value you read:
Serial.println(voltage);
}