A Chirotron measured a persons weight utilizing 4 quadrants, heel and insole of each foot. A Chiropractor then used the measurements to analyze the health of a person's spine.
It took 8 readings, 1 per second so the doctor could also see the sway of a person which indicated balance.
After the unit failed, the doctor tried to replace it, or get it repaired but to no avail. He found out there is nothing like it out there anywhere and the company was no longer in existance.
If you doubt my words, try to Google it. So there it sat on a shelf in a storage room for over 20 years.
The goal in this project was to convert the old original Chirotron electronics to new Arduino technology, have it operate wireless over WiFi, so it can be operated by any device, a tablet, smart phone or desktop computer.
It must also have a host web site to allow the entry of new patients and to store their weighing results.
So the challenge begins. (Note: click on an image to see it full size.)
First I took it apart and found it to be a very well designed unit.
The case was heavy and the load cells were massive, able to handle up to 300 pounds each.
The fellow who designed and built this unit was a genius.
I removed one of the 4 quadrants. As you can see it was well built.
Here is a load cell with its new HX711 installed.
The HX711 converts the weight applied to the load cell to a analog voltage level the Arduino can read.
Here is the completed unit. I used a WiFi shield 101 (no longer available).
I tried to use the ESP8266 but was too flaky.
However with this shield I ran out of programing space and had to switch to an Arduino Mega, which meant redesigning the whole thing.
I also 3d printed the mounts for the electronics as you can see here. I also incorporated a jack so I could program the Arduino without taking the unit apart.
Aerospace wiring throughout.
Over the circuit boards I mounted a white translucent plate. Behind the plate are 2 LEDs.
The left one flashes whenever the Arduino is processing and the right one glows green when a WiFi connection is made.
I added a cool footsie label to show a patient how to stand on it, and a SD card to allow entering in a new WiFi router and password.
The Web site to control the scale was written in PHP and uses a MYSQL database.
The other challenge was to make the software HIPPA compliant.
In conclusion this was a challenging project but also a fun project and if you have any questions please call or email.