Humanoid robots uses pressure sensors on the feet to balance themselves. The following video shows an example of using pressure sensor to balance a robot.
A robot dog also uses pressure sensors to balance.
The horse shoe project may
need a compact load cell with a strain gauge inside to measure the
pressure of a horse stride to diagnose leg injuries.
Here is the example that uses
the same strain gauge and load cells I have in the lab. Apparently, one
cell has two strain gauges. You will need to add two 1k resistors to
form a half wheatestone bridge.
A strain gauge (also spelled strain gage) is a device used to measure
strain on an object. Invented by Edward E. Simmons and Arthur C. Ruge
in 1938, the most common type of strain gauge consists of an insulating
flexible backing which supports a metallic foil pattern. The gauge is
attached to the object by a suitable adhesive, such as cyanoacrylate.
As the object is deformed, the foil is deformed, causing its electrical
resistance to change. This resistance change, usually measured using a
Wheatstone bridge, is related to the strain by the quantity known as
the gauge factor.
Here is a video shows that
the resistance change is small and the resistance changes with
temperatures. So the quater bridge strain gauge circuit is not a good
idea.
The resistance change is
small so you need the Wheatstone bridge and an amplifier to make it
readable. The following one is the module we are going to use in the
lab.
Here is a snapshot from the datasheet that shows the connection.
The connections to build a scale:
Tasks: 1. Use ATMEGA 328 (Surface Mount), HX711, and four
load cells (unit in kg) to build a mini scale. Read the data into the
serial monitor. You can use the acrylic board in the lab. You may need
to 3D print a mount for the load cell for the board. Keep in mind that
the goal of this task is to build a DIY scale kit that can be sold to
K-12 students as a toy. It must be small and cost effective. Publish the commented code, 3D print design file, and the tutorial to build this scale in your lab report. 2. The PCB must be free of
commercial modules on it, which means that you must use barebone MCUs,
your schematic for the HX711 board, a voltage regulator, and other
peripherals.
