Arduino Uno + 2 x RB-Onl-38 + 4 x load cells

A common question concerning our Wheatstone bridge amplifier shield since the creation of the blog post Interfacing a Load Cell With an Arduino Board is “How can we stack two shields together with three or four load cells?”

This is actually quite simple and only requires a few components:

• An Arduino Uno or other Arduino shield compatible microcontroller board, such as the BotBoarduino
• Two RobotShop Wheatstone bridge amplifier shields
• Three or four 4-wire load cells
• Some stacking headers, such as RB-Ite-58, RB-Spa-697, RB-Spa-928, RB-Fee-27 or RB-Ada-08
• Some male to female jumper wires, such as RB-Cix-18 or RB-Dfr-96

First, place the first shield on top of the Arduino and connect your load cells to the shield. Then add the stacking headers and the second shield, bending the stacking header pins for A0 and A1 outwards.

Stacking header pins bent outwards on pins A0 & A1

Use some male to female jumper wires to connect the bent pins to the top shield’s female header at the A2 and A3 positions.

Bend pins A0 & A1 connected to top shield’s A2 & A3

Finally, obtain a fresh copy of our Wheatstone bridge amplifier shield Arduino library from the RobotShop GitHub repository for this project (or download directly as a zip). It now includes an example that is ready to go for quickly testing your setup with two shields and four load cells.

Of course, since most Arduino-shield compatible microcontroller boards have also A4 and A5 pins, you could in theory stack a third shield, following the same method described above. Anyone interested in trying that out?

The original link: http://www.robotshop.com/blog/en/arduino-tutorials-how-to-stack-wheatstone-bridge-shields-19129