DAY 1
Monday, 05/08/2024
On this day, we fixed the door (for cleaner access) and chute (for users to throw their trash) onto the metal frame using hinges. Next, we screwed the load cells onto the wooden board to ensure that they would be permanently and securely attached to the board, preventing inaccuracies in weight measurements. This involved hot-gluing the load cell to the mounting frame to prevent them from moving around, and subsequently screwing them into the wood using a screwdriver.
Our PCB also arrived today, so we soldered JST-XH 2.54mm sockets into the PCB, enabling us to directly connect the wires of various appliances to the PCB.
On the software side, we continued working on the app, which is now able to lock and unlock 2 dustbins on the iOS simulator that is connected to Adafruit IO.
DAY 2
Tuesday, 06/08/24
We connected all electronics to the PCB today.
However, due to poor soldering on some pins, several of our electronics did not function when we ran their code. For instance, our light was not functional, despite running a very simple code for it to light up. It took many rounds of testing connections using the DMM and editing the code before realising that it was a PCB soldering issue. It was rather difficult to detect the improper soldering, so we had to disconnect and re-solder various pins multiple times throughout the day.
The last thing we did was test the app’s functionalities. It was programmed such that when either one of the ultrasonic sensors detected a distance of less than 15cm, or the load cells detected a weight of over 1kg, the electromagnetic lock would automatically lock, preventing users from opening the chute and throwing in more trash, and the light would light up. These parameters of weight and distance used were just placeholders used for testing purposes. To our excitement, the app worked! It was also able to display the exact distance & weight that the ultrasonic and weight sensors detected respectively. Additionally, the app would indicate that the bin was ‘full’ when one or more of the aforementioned criteria were met.
DAY 3
Wednesday, 07/08/24
We focused on re-confirming the positions of the ultrasonic sensors today. Previously, we did preliminary trials on their positioning to determine the appropriate length of wire to use. The objective of today’s positioning endeavour was to find out the threshold of the sensor’s object detection capabilities (i.e. at what distance/angle below the sensor does an object have to be for it to be detected). We felt that this was necessary as the current chute’s inner flap was too long/angled incorrectly, which caused objects thrown in to fall outside of the bounds of the inner bin. As such, first confirming the positions of the ultrasonic sensors would make it easier to redesign the inner flap so that trash would land nicely into the inner bin, without blocking the ultrasonic sensors.
However, due to time constraints, we did not manage to confirm the ultrasonic sensors’ positioning, and planned to continue with it next week instead.
^ the current exterior of our bin (before hiding the cables + beautification)