Hello, im trying to figure out what are these readings for GSR Grove sensor (connected to A0 in Arduino board)
what are these readings? i need to know please for college project? are they skin resistance values? and what code necessary to convert them to skin conductance values? (Micro_Siemens)
what are these readings?
A voltage level on one of the analog pins.
are they skin resistance values?
Not directly but they depend on the skin resistance value if the sensor is applied correctly.
and what code necessary to convert them to skin conductance values? (Micro_Siemens)
You need to calibrate the sensor. The Grove sensor is not designed to deliver µS values. It's thought to show changes in the skin conductance and not to provide absolute values.
pylon:
A voltage level on one of the analog pins.Not directly but they depend on the skin resistance value if the sensor is applied correctly.
You need to calibrate the sensor. The Grove sensor is not designed to deliver µS values. It's thought to show changes in the skin conductance and not to provide absolute values.
thanks alot for your reply, im sorry for the dumb question but how can i calibrate the sensor to get skin resistance and skin conductance value? sorry im still new to arduino and sensors
i got this equation from a website:
Human Resistance = ((1024+2*Serial_Port_Reading)*10000)/(512-Serial_Port_Reading), unit is ohm, Serial_Port_Reading is the value display on Serial Port(between 0~1023)
should i get the resistance from this equation then convert them to skin conductance (i read conductance is simply the inverse of resistance)
even though i tried this equation and put the SensorValue in place of Serial_Port_Reading, it didnt give values expected for resistance in ohms (from 50k to 10M)
what do i do please?
"i read conductance is simply the inverse of resistance". Correct. 1/resistance is conductance. 1 microSiemen is 1 meg ohm.
Paul
that's great thank you, but any idea how to get the resistance from these readings?
any idea how to convert these GSR readings into skin resistance or conductance? i only have 3 days to complete this project 
how can i calibrate the sensor to get skin resistance and skin conductance value? sorry im still new to arduino and sensors
Get two resistors with known resistance and attach them instead of the skin sensor to the breakout board. Note the two values, the interpolation should be linear.
i got this equation from a website:
Human Resistance = ((1024+2*Serial_Port_Reading)*10000)/(512-Serial_Port_Reading), unit is ohm, Serial_Port_Reading is the value display on Serial Port(between 0~1023)
Excuse me but this is bullshit. The GSR Grove sensor includes three op amps to boost the voltage to a level the Arduino is able to measure. The board also has a potentiometer to adjust the value. So the equation almost most include calibration values measured on the actual board settings.
pylon:
Get two resistors with known resistance and attach them instead of the skin sensor to the breakout board. Note the two values, the interpolation should be linear.Excuse me but this is bullshit. The GSR Grove sensor includes three op amps to boost the voltage to a level the Arduino is able to measure. The board also has a potentiometer to adjust the value. So the equation almost most include calibration values measured on the actual board settings.
attach them instead of skin sensor you mean in A0 analog pin ? because that where the sensor goes also where i will i attach sensor on the board after it?
here is the sensor two wires on voltage and ground and one on analog A0
attach them instead of skin sensor you mean in A0 analog pin ? because that where the sensor goes also where i will i attach sensor on the board after it?
No, the Grove sensor board has a terminal where the actual sensor is connected. You have to attach the known resistor values there. Keep in mind that these resistors are key for the accuracy you will get. So if you attach a resistor with 5% accuracy (the default) the measured value will have an accuracy of +/- 10%. So to get useful values you should use resistors with 1% or better.
I found the page where you got the equation from. There they describe a very simple calibration method. If you do that you will get values in Ohm with the mentioned formula but you have no clue about the accuracy.
malfinzulkarnaen:
what code necessary to convert them to skin conductance values? (to ohm)
Did you read my last answer?
