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 microcontroller (as MCU) in a PCB2. Ultrasonic sensor
3. Slide Switch
4. 3.5mm Screw Terminal
5. 2x 8 Pin Female Header
6. FTDI Header
7. 2500mAh Lithium Ion (LiPo) Battery
8. 5V Boost for Lithium Battery JX-887YDC Boost Converter
9. Neopixle LEDs strip
Packaging
3D Design
I used Autodesk Fusion360 to design the packaging of this unit. I saved the design in two ways, one to be cut by the Laser Cutting Machine and one to be printed by a 3D printer.
Design for Laser Cutting
Design for 3D Printing
3D Printing
I used blue PLA/PHA material and printed in the Ultimaker Extended 3D printer
Settings:
The following video shows how the project works after assymbling the 3D body with the electronics part and the top acrylic board.
Laser Cutting
I used 3mm White Coated MDF material. And I used the default settings of this material in the Universal Laser Systems Machine
I covered it with a black 3mm acrylic
Resin Art
I used this tool I have at home to unwnted remove resin
Electronics
I used Autodesk Eagle to design Printed Circuit Board of this unit.
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
While removing the board, I cut one of the VCC traces. Then I fixed it by using a wire.
The PCB connected with the battery and the boost converter.
Testing
Ultrasonic Sensor has been tested in Input Devices week
ESP32CAM
I used the example code in Arduino IDE software to test the camera.
Serial monitor
I copied the link and put it in the web browser >> Then Start Streaming
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
5V Boost Module JX-887Y
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.
Problems Faced:
I broke the first board
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.
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.
My Future Plan:
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.
Laser Cutting
I used 3mm White Coated MDF material. And I used the default settings of this material in the laser cutting machine
Testing
Output Device: DC Buzzer
It has been tested in Output Devices week
Files list:
| Outdoor unit packaging design | Fusion360 File |
| Outdoor unit packaging design | stl File |
| Outdoor unit board | Eagle File |
| Outdoor unit schematic | Eagle File |
| Outdoor unit (traces) | png File |
| Final Programming Code | Arduino IDE File |
| Future Indoor unit packaging design | Fusion360 File |
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