SparkFun Load Sensor Combinator [BOB-13878] - (AD22842)

Description:

The SparkFun Load Sensor Combinator is a Printed Circuit Board (PCB) that combines four load sensors into a standard four-wire Wheatstone bridge configuration. If you crack open an electronic bathroom scale, you’ll find a mess of wires. The Load Sensor Combinator was created to combine the 12 wires of a bathroom scale into the standard four-wire Wheatstone bridge configuration.

This version of the SparkFun Load Sensor Combinator includes a few changes that you specifically asked for! We updated the silkscreen for the hookup board to read "C/+/-" instead of "R/W/B" and moved the temp sensor connector away from the breakaway hole.

You can either use four individual load sensors or simply buy a standard bathroom scale and integrate the combinator into it, rather than trying to design a base to properly mount four load sensors.

This board works perfectly with our Load Cell Amplifier Breakout Board; the five edge pins of the combinator line up directly to the five pins on the amplifier.

If the amplifier and supporting electronics are more than a few inches away from the scale, an RJ45 jack is provided. The four Wheatstone pins (E+/E-/S+/S-), as well as the shield pin, are connected to twisted pairs inside a standard and inexpensive Ethernet cable. This allows the amplifier board to be located many feet away from the scale.

The combinator board also includes a connection for the DS18B20 one-wire temperature sensor. This allows the user to log the scale’s temperature in case of a large variation between the scale and the amplifier. These three pins are accessed through the RJ45 jack, allowing remote temperature readings via a twisted-pair Ethernet cable.

Documents:

• Schematic
• Eagle Files
• Hookup Guide
• Getting Started with Load Cells
• GitHub