CE432 Robotics II Fall 2022
Homework 4 - The Strain Gauge
Name: Ryan Jeanes
Email: rejeanes@fortlewis.edu
Homework 4 - The Strain Gauge
Introduction
For this assignment, we are learning how to use a strain gauge with a half wheatstone bridge to measure the weight of whatever is placed on the loadcell the strain gauges are glued in to.

Task 1
Task 1 was completed succesfully. For the HX711 I used the HX711 library by Bogden Necula. The results for Figure 1 had some inaccuracy after calibration that was likely caused by not having a solid surface that the loadcell could be mounted onto.


Figure 1 - Screenshot of the data read from the strain gauge, with 1st reading having nothing on the gauge and the last 2 readings with my hand pressed down on the loadcell.

Task 2
One of the two ESP32S boards I brought home to use for this assignment had a damaged serial circuit. I believe this to be the case because of the error displayed in Figure 2 as well as the fact that the ESP32S was getting really hot in the area near the EN button with the only connection being the USB cable. I tried to use the ESP32-CAM board, but was not able to establish a connection between the two even when using the ESP-NOW example sketches with the proper MAC addresses, despite seemingly being able to establish peers due to no errors being printed during that process.


Figure 2 - Screenshot of the error message displayed when attempting to upload to one of the ESP32S boards.

Update: I understand if this bit doesn't count, but I didn't have time to drive back to The Fort Monday to grab a replacement ESP32S. I grabbed one this morning to try and it worked after making a minor change to the code to fix an error due to forgetting to change a variable name after changing the example code back to what I had tested with.


Figure 2 - Screenshot of data received from ESP32S connected to strain gauge.


Figure 2 - Screenshot of data received from ESP32S connected to strain gauge.
Appendix
Code for ESP32-CAM Receiver
Code for ESP32S Sender.