I'm trying to take the output from a weighing scales and hook it up to my arduino Leonardo. I'm not no expert at electronics and I'm having some trouble.
The weighing scales consists of four 1/2 wheatstone bridges connected together, so I'm taking the output of these (S+ S- E+ E-) and hooking it up to the Texas Instruments INA125 Instrumentation amplifer, following the attached diagram.
When I connect my output to the arduino, my serial monitor code spits out values between 681 and 683, with no variance when pressure is applied to the load cells.
I'm not sure what to do from here, any advice would be greatly appreciated!
I don't have a datasheet for the loadcells, or for board that joins them all together and generates one output
(S+ S- E+ E-). I've looked it up but can't find anything on it.
When you're using for a load cell, the proper resistor value for the gain setting for the INA125P is typically between 50 and 200 ohms, and if you're off by more than ~5 ohms you won't see much change in the reading.
If you're seeing an output voltage (from the INA125P) of ~4V then you need a higher ohm resistor. If the output voltage is always ~1.5V then your resistor is too high a value. Keep trying different resistors until you get a value that's somewhere in-between and then at that point you'll know you're getting close.
