Hi,
I have 4 load cells which calculate upto 200 kg each. i want to place them under the four legs of table and calculate the combine effect of them when load is placed upon them using arduino.
Load cell is of 4 wire
Red = E+
Black = E-
Green = S+
White = S-
Using four times meanz i have to use four ina125p and four analogue pins..?
Agebee i still have some problem in setting gain (Rg)... can u guide me in setting that..?
whats the purpose of it..? What does gain do..? how it can be set in my case..?
i get this formula from ina125p for gain
What is the full scale output from the load cell? The full scale output (FSO) should be specified in mV/V. What is your excitation voltage? What is the analog converter reference voltage? You need that info, at a minimum, to know what the gain needs to be. Rg is the gage resistance. Can you link to the load cell datasheet or specifications?
And to find the weight of the table and contents you must SUM the load cells if there is a load cell under each leg.
I meant under each corner. The FSO is 2 mV per Volt of excitation. If the excitation voltage is 5 V the output at full scale load from the load cell is 10mV (0.002 * 5). Further, if the ADC reference is 1.1V you need a gain of 1.1/.010 = 110. You must balance the bridge of the load cell prior to amplification.