Yue Pan, Zhou Lu
Demo Video Link: https://youtu.be/D2i0VEtWlDY
Presentation Video Link: https://youtu.be/cG2J5QSIfjU
GitHub Webpage: https://cpa872.github.io/ECE-4180-Final-Project/
MBED Repo Link: https://os.mbed.com/users/cx872/code/4180-final_project/
HVAC Control in old Apartments (e.g. North Avenue East) is achieved through a wall-mounted knob. Problems are: Inaccurate: Unknown set temperature value Room temperature will vary in a big range around the “set” temperature Inconvenient No Remote Control HVAC control knob in NAE
Set temperature is adjusted via interrupts on push buttons Using RTOS with 4 threads Prints temperature and humidity on the LCD Compares set and current temperatures to control the servo Actuate servo when current temperature is outside set_temp ± 1 degree Celsius�set=22.0, cur=23.1 → turns ON, until set=22.0, curr=21.9 → turns OFF Once servo actuated, it will be locked for 1 minute prevent overheating Prints ON/OFF under the “ACT” field on the LCD Software polling loop for monitoring Bluetooth and change set temperature accordingly Temperature and Humidity updating (mian thread) Prints numbers to specific areas on the LCD
Microcontroller -- MBED
Familiar with the interface, works with components in hand
Plenty of GPIO, PWM output, I2C and serial interfacing pins
Display -- uLCD-144G2
Familiar with library and coding standards
Size is perfect for such small applications and does not draw too much power
Thermometer -- BME 280
High accuracy, easy library set up
Remote Control -- Adafruit Bluefruit
Familiar with the interface, connection is easy to set up and usually stable
Another option could be ESP8266 based, but the control interface must be accessible from the same subnet, which is infeasible given campus network setup
Rotation Actuator -- HITEC HS-422
Larger torque than the more common SG-90, can rotate the knob easily
Easily controlled via PWM
Power Supply -- Arduino power supply module
Mountable on breadboard and provide multiple power out pins including dedicated pin for servo
Provides one USB 5V output to power the MBED
We would like to actually use this design in our future apartment (8th Street East)
The servo needs to be more firmly fixed onto the surface
May consider replacing the power supply module because the regulator on it is very hot during operation
Can add a “force on” feature using the 3rd button that turns on the HVAC without changing the set temperature