Greetings!
Despite reading the documentation, I was left confused by how (or if?) the SparkFun Qwiic Scale (SEN-15242) can be used with a single, 2-lead load cell. I am only measuring tension (so I don’t need differential), and my load cell is a 120 Ohm type. Basically, is there a way to use this as part of a quarter bridge circuit?
Thanks!
You will need 3 other 120 ohm resistors connected to form a wheatstone bridge.
I figured, but how would I connect them to this product?
Again, that doesn’t explain how to hook that up for this product. I understand what a conventional Wheatstone bridge is. Thanks.
Your sensor is one of the 4 resistors in the diagram. You need three other resistors to complete the bridge. It doesn’t matter where you put the sensor, just that you have all 4 devices connect in the bridge configuration.
Yes, I know that as well. I mean what components plug into each port on the SparkFun Product?
A and B:
Red/E+ - Positive voltage of load cell energizing the wheatstone bridge. Most often connected to the red wire of a load cell.
Black/E- - Negative voltage of the load cell, most often connected to the black wire of a load cell.
C and D:
White/A- - Negative branch of the wheatstone bridge, most often connected to the white wire of a load cell.
Green/A+ - Positive branch of the wheatstone bridge, most often connected to the green wire of a load cell.
I’m not using a load cell, as I said. I will assume then that I should connect 3 high-precision resistors as R2-R4 that match my strain gauge’s nominal resistance.
