Week 16

System integration

Week assignment Individual assignment:

• Design and document the system integration for your final project.

Weekly Task Development

I am documenting all the development of this system integration tasks in the
Project Development Week 15-16 section.

Tasks Completed:

• Design and fabrication of the central PCB and the PCBs that will be placed under each seat on which I will place an HX711 ADC

• Design and fabrication of the frame that will house the LEDs. I still need to define the outer case that will integrate the power supply and the main PCB.

• Design and printing of 544 caps for each cell. (wip) 17 rows by 34 columns. I prepared a grasshopper strategy defining the parameters of layer size and number of perimeters to adapt the geometry to the characteristics of the model as much as possible. And I set the printers to print

• Modeling of the seat. (Updated week 17)

• Load cell PCB case. (Updated week 17)

• Load cell case dimensions Test case model for seat PCBs

During week 18, the integration of the project continued to progress. I have completed the structure that will support the seats.

I have also wired the electronics of the nine boxes that house the PCBs connected to the load cells. The three cables that gather readings from load cells 1–2–3, 4–5–6, and 7–8–9 run longitudinally along the bench and reach its right end, where they connect to the PCB responsible for collecting and transmitting the data via WiFi to the MCU that controls the LED matrix.

Wiring organization example at load cell number 9. The leftover foam from the seats has been used to hold the cables in place, making assembly easier. In the detail, the three superimposed cables can be seen, through which the readings from the nine load cells are transmitted, grouped in sets of three.

Finally, I prepared the enclosure for the central PCB, which will be mounted on the end of the wooden beam, easily accessible for programming and power supply.

The integration of all system components is nearing completion. Everything is securely fastened, and no loose wires are visible that could disconnect or get pinched during normal use of the final project.

On Tuesday, June 3rd, I completed the wiring and installation of all the components of the beam.

Also this week, just one week before the final project presentation, I finished assembling the LED frame. I designed a bottom case that houses the power supply, the PCB, and the power button, as well as a set of indicator LEDs that will display system status as soon as it is powered on.

In this final image, I show the front panel of the LEDs. In this case, it was a failed attempt, as I mistakenly placed the components on the wrong side. Nevertheless, I will keep it as a memento.

You can check the progress of all the work I am doing at the following link:
Link to Project Development

BOM

Hardware

Electronics

Files week 16

HX711 Load cells case. stl. zip
HX711 Load cells lib. stl.zip
Central PCB case. stl. zip
Central PCB Lid. stl. zip