1. ISA CLICK CONTROL #38 – FALL 2014 ERIC BRUNNGRABER DRAKE ISABIRYE

2. Introduction A system by which a fan may be turned on or off remotely. The fan can be set to automatically turn on or off depending on the temperature. The fan can be set to turn on or off after a certain amount of time. System could potentially be used to control other household devices as well.

3. Objective Create a remote control that can send information from user inputs to the fan through a Wi-Fi network. Create a unit that: – Receives and interprets user commands through the Wi-Fi network – Serves a web page through which the fan may also be controlled – Interprets data from a temperature sensor – Switches on and off the fan

4. Overview

5. Original Remote Control Plan

6. Remote Control Pad

7. Remote Control Pad Requirements Battery must supply enough power in order to maintain a voltage of 4.8V at the output of a voltage regulator. When a push button is pressed, it must pull up the voltage of its corresponding bits up to above 4.8V. The output voltage of bits not intended to be high must be less than 0.2V.

8. Remote Pad Testing Using a L7805 voltage regulator after a 9V battery, we were able to maintain a high logic voltage of approximately 4.95V. The four output bits had appropriately high and low voltage outputs to be interpreted by the microcontroller. Using LED’s, we confirmed that each button gave the proper 4-bit output.

9. Remote Pad Testing PUSH BUTTON INPUTLOGIC OUTPUT 10001 20010 30011 40100 50101 60110 70111 81000 91001 01010 Switch1011 Delayed Switch1100 Time Switch1101

10. Remote Microcontroller

11. Remote Microcontroller Requirements For each push button input, the remote control microprocessor must give a single, 4- bit serial output corresponding to the button that was pressed.

12. Remote Microcontroller Testing While we originally planned to use the ATMega328P microcontroller on its own, we demonstrated using an Arduino Uno, which itself uses the ATMega328P microcontroller.

13. Remote Microcontroller Testing Faced this issue of Arduino producing random outputs with no inputs while testing with the remote pad on a breadboard possibly due to static. This problem was resolved when we actually soldered the circuit on a vector board. Initially there were issues with switch bouncing; however, we fixed this by improving the debouncing code.

14. Remote Microcontroller Testing Using pins 12, 7, 4, and 2 as the four input bits, the Arduino Uno did properly generate a serial string of bits correctly corresponding to each input.

15. Original Receiver Plan

16. Receiver

17. RECEIVER MICROCONTROLLER

18. Receiver Microcontroller Requirements The output to the switching unit must be less than 0.2V when low and more than 4.8V when high. The output must switch from low to high or high to low upon being given a switch command. Given the timed switch command, ensure that the command is carried out within two seconds of desired delay time.

19. Receiver Microcontroller Requirements Upon receiving a temperature input of greater than 70 degrees Fahrenheit from the temperature sensor, the output from the microprocessor must be high. The display must display the temperature reading received from the temperature sensor.

20. Receiver Microcontroller Testing As with the remote control, we used an Arduino Uno for the purpose of demonstration. To test, we connected the remote directly to the microcontroller due to problems we faced with the Wi-Fi system. The controller did however respond properly to the commands from the remote, including the switch and delayed switch.

21. Receiver Microcontroller Testing We used a TMP36 temperature sensor, which has an output voltage proportional to the room temperature it senses. Using the temperature sensor input, the Arduino properly displayed the current room temperature on the display. By adjusting the temperature threshold at which the fan should turn on and off, we confirmed that the controller properly switched the fan given the current room temperature.

22. Switching Unit

23. Switching Unit Requirements An input voltage of greater than 4.8 volts must cause the relay to switch on. While the relay switch is on, its output must have a voltage greater than 11V. Fan activates when relay switch is on.

24. Switching Unit Testing We initially wanted to connect our JCZ-11F 5V relay directly to the Arduino, but the voltage at which the Arduino operated was not enough to switch the relay. We solved this by using a NPN transistor connected to the output of the Arduino, which would allow the 12V supply power to drive the relay. This worked, and allowed the fan to be turned on and off by the controller.

25. Switching Unit Testing Initially we had one resistor in series with the fan motor to protect it, but this resistor burned, so we added several more heavy duty resistors in parallel to reduce the power on each one. This solved the problem.

26. Wireless Connection Requirements Data transmitted from the remote’s Wi-Fi card is received by the receiver’s Wi-Fi Card. The computer receives the web page data from the receiver’s Wi-Fi card.

27. Wireless Connection Testing We originally intended to use RN-XV WiFly modules as Wi-Fi cards, allowing for wireless connectivity, but these proved temperamental and one of ours died while we attempted to configure it, which caused us to seek an alternative.

28. Wireless Connection Testing We then attempted to use XBee modules that connect to each other but also have Wi- Fi capability. Both of our modules died during our attempts to configure them. Unfortunately, this left us with no way to demonstrate wireless capability and no way to develop or test the web page.

29. Next Steps Configure the XBee modules and establish the wireless connection between the remote control and receiver. Develop and test the web page. Replace the Arduinos with the ATMega chips directly on the boards.

30. Further Work Find ways to lessen the power consumption of the Remote Control for improved battery life. Create cases for the remote control and receiver unit for safety and durability. Develop receiver units that can be used in other applications involving a device controlled by remote command and sensors.

31. Conclusion We managed to create a remote control that effectively generated a serial output based on a user’s push button command. We created a receiver that effectively processed commands, read sensors, displayed information, and performed a switch. Thank you for your support!