This project is an electrically locked box. You can safely store things that you are addicted to inside it and unlock it by reaching a particular goal. I'm going to put sweets in it and unlock the box once I've reached my daily calorie target on my smartwatch. Inside the box is a load cell that can roughly detect the amount of sweets taken out. In addition to that, there is a wireless charger, that will charge e.g. your phone while beeing busy.
I often find myself looking at my phone a lot when I'm busy, which slows me down. Furthermore, I also want to do more sport. With the box, I can combine these things and create my first PCB, build a large 3D model, and learn many other skills.
servo motor: connect the red cable to +5v hall effect sensor: when facing the smaller side the left once is +5v, the middle one GND and the right one signal HX711: this board is solderd directly on the PCB in the only possible direction power: connect the 5V of the USB-C connector with the +5V on the board and the +5V on the wireless charger, same for GNDGND
| Description | price in € |
|---|---|
| 2 pices M4 DIN9021 to spread the pressure over the box | 2X0,24=0,48 |
| 2 pices M5 DIN9021 to spread the pressure over the box | 2x0,29=0,58 |
| 2 pieces M5 domed cap nut | 2x0,49=0,98 |
| total price in € | 2,04€ |
| total price in $ (7/17/2025 at 4:44pm under: https://www.visa.de/support/verbraucher/visa-reiseservices/exchange-rate-calculator.html) | 2,39$ |
| Description | price in $ |
|---|---|
| 2 pices M4 DIN9021 to spread the pressure over the box | 4 |
| shipping cost | 3,3 |
| total | 7,3 |
| Description | price in $ |
|---|---|
| aliexpress | 47,56 |
| local building center | 2,39 |
| PCB | 7,3 |
| 3D-Filament | nothing - I have to use Printing Legion because I have no 3D-Printer yet 😥 |
| total | 57,25 |