This week
I successfully completed assembling the Sensor Matrix PCBs’ wiring. We encountered a challenge when we discovered that the pin header we used in Fusion 360 had a different pitch than expected. To solve this, we created our own braided wiring, ensuring both rigidity and effective electrical contact. Additionally, the Arduino ammeter modules arrived, leading me to splice our wiring cable for the wireless charger and begin testing. My tests focused on several aspects:
– The speed at which the charge current is detected after placing a device on the charger.
– How quickly the current decreases once the device is removed.
– The variation in current as the device continues to charge.
– Differences in the charge current curve for various devices (phones, earbuds, etc.).
– The occurrence and timing of the charge current plateau and the device’s charge state at that point.
During testing, I noticed that our charge current never exceeded ~2.5A, while our module was designed to measure up to ±30A. This limitation resulted in poor resolution for small currents. To address this, I found and ordered a new ammeter module with a maximum range of 5A and significantly improved resolution.
For the table’s top, I decided on the material in collaboration with Callum and Luca, and placed the order through Quinn.
Schedule
It appears the entire team is back on track. We have nearly finished the mechanical subsystem and most of the electronics. Our next steps involve adding final touches for the system integration of all components and then incorporating features to elevate our project beyond the minimum viable product (MVP), such as screen integration and selectable charging modes.
Next week
My focus will shift to working on the wood surface for the table’s top. This involves cutting it to the right shape, ensuring proper measurements, and providing adequate support around the frame’s edges. We might need to use 3D printing or screws for this. Depending on the wood’s thickness, we may also etch channels into it.
Additionally, I’ll collaborate with Callum on sensor integration to complete the sensing mechanism before the Interim Demo. This involves assembling all components and integrating the cables with our frame. We may also design a 3D-printed lip that attaches to the frame to secure the electronics.
Once these tasks are completed, I will start testing the charge current with the new, more sensitive ammeters.