Trulli Sara Alhadhrami Website - FabLab Academy

Final Project

Smart Doorbell


A smart doorbell that sense the existence of a person automatically and generates the doorbell sound. This project will consists of two units. One unit will be outside home to sense objects and transmit signals through wireless communication to the inside home unit to generate the bell sound immediatly as it receives the signal.







1. Outdoor Unit


This unit consists of:
1. ESP32CAM
2. Ultrasonic sensor
3. Slide Switch
4. 3.5mm Screw Terminal
5. 2x 8 Pin Female Header
6. FTDI Header
7. DC Boost Converter



Electronics

I used Autodesk Eagle to design Printed Circuit Board of this unit.

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I made the distance between the 8 pin female headers 23.57mm because this is the distance between the pins of the ESP32CAM


I used milling machine to mill the board then I soldered the components

Trulli

While removing the board, I cut one of the VCC traces. Then I fixed it by using a wire.

Trulli

Trulli

The PCB connected with the battery and the boost converter.

Trulli



Testing


Ultrasonic Sensor has been tested in Input Devices week

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ESP32CAM

I used the example code in Arduino IDE software to test the camera.

Trulli

Trulli

Serial monitor

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I copied the link and put it in the web browser >> Then Start Streaming

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Troubleshooting

ESP32CAM

- While connecting the esp32 with the pc through the FTDI cabel, the esp becomes very hot, which means that there could be a short circuit either in the board or in the esp32cam. I tested the board alone by using the multimeter and its fine there is no short circuit. Then I tested the esp32cam alone and its fine there is no short circuit. After that I checked them together by connect the esp32cam with the board and using the multimeter to check if there is a short circuit between the vcc and gnd. Yes, there is a short circuit now.
The problem is that the right side of the esp32cam is fliped in the board and I forget to connect the vcc pin at that side.
I fixed the circuit board from the schematic and I milled a new PCB.





Power

This unit is powered by Lithium Ion Battery and a 5V boost module for Lithium Battery JX-887Y to convert the 3.8V coming from the battery to 5V to power the ESP32CAM, the Ultrasonic sensor and the Neopixel LEDs.


2500mAh Lithium Ion (LiPo) Battery

Trulli


5V Boost Module JX-887Y
Trulli




Wireless Communication

I used Wireless communication in this project by using Bluetooth in ESP32CAM in the outdoor unit and Bluetooth in indoor unit which is an Android phone and tablet.

In Interface and Application week I described how I used MIT APP Inventor to design the App that I used in an Android tablet. With the App I connected Bluetooth in the tablet with my smart doorbell.




Programming

This is the link of the final code I used to control the ESP32CAM microcontroller with the Ultrasonic sensor and the NeoPixel LEDs plus the Bluetooth communication between the PCB and the App.




Packaging


3D Design

I used Autodesk Fusion360 to design the packaging of this unit.

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Trulli

Laser Cutting

I used 3mm White Coated MDF material. And I used the default settings of this material in the Universal Laser Systems Machine

Trulli

Trulli

Trulli

Trulli

I covered it with a black 3mm acrylic

Trulli

Resin Art




I used this tool I have at home to unwnted remove resin






Problems Faced:

I breaked the first board

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Then I milled another board. I realized here that I switched between VCC and ECO pins. I fixed that by cutting the traces and solder it again by using wire for the vcc and I soldered the eco trace directly.

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After that I found another mistake. I reversed the right side of the ESP32CAM header which caused short circuit between VCC and GND. Finally I fixed the design and I milled the board agian.





Future:

Indoor Unit


This unit will consists of:
- ATtiny44
- DC Buzzer
- Hc-05 Bluetooth Module

Electronics

I used Autodesk Eagle to design Printed Circuit Board of this unit.

Packaging

3D Design

I used Autodesk Fusion360 to design the packaging of this unit.


Trulli Trulli Trulli

Laser Cutting

I used 3mm White Coated MDF material. And I used the default settings of this material in the laser cutting machine


Trulli

Trulli

Testing


Output Device: DC Buzzer
It has been tested in Output Devices week

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Files list:

Outdoor unit packaging design Fusion360 File
Outdoor unit board Eagle File
Outdoor unit schematic Eagle File
Future Indoor unit packaging design Fusion360 File
Final Programming Code Arduino IDE File





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