The squirrel fans used to levitate the ping pong balls inside each tube were rated at 12V; therefore, the 3.3V output of the A3BU was not enough to drive the fans. Examination of Figure 4 (see Schematics section) reveals that we used a transistor and a 12V DC power supply to amplify the driving voltage of the fans. Each fan motor was connected in parallel with a capacitor and a protective diode. The 12V DC power was connected in series with each motor, capacitor, diode set, making the motor fans in parallel with each other so that each draws an equal 12V as needed. The input to each transistor was preceded by a 220Ω resistor in series with the transistor. The signal of the transistor was connected to ground of the motor, capacitor, diode set to control how often the 12V DC was to be pulsed across the motor. Consequently, the use of an npn transistor allowed us to scale our pulse width modulation signal from the A3BU (0-3.3V) to a 0-12V signal that drives the fans.
The goal of our project was to create a visual representation of the input frequencies collected by a microphone. To do this we had to receive an analog signal from a microphone, and use this signal to drive the speeds of three different fans. After receiving the signal from the microphone, we ran the raw electrical signal through a fourier transform in order to distinguish the various frequencies within the signal. Once we had the multiple frequencies that made up our signal we divided these frequencies into 3 separate bins: low, medium, and high. We used the average of these bins in order to determine the speed at which the fan should run. If the average of the frequencies contained in the low bin increases, then the speed at which fan 1 is rotating will also increase. Fan 2 which corresponds to the medium range frequencies, and fan 3 which corresponds to the high range of frequencies, both operate in a similar manner. Our goal was achieved as we were able to get the fans to fluctuate in speed based on the various frequencies collected.
Step 1: To make one of these sensors start by taking a piece of duct tape the length of the finger it will be used for.
Step 2: Then cut a piece of conductive thread that is long enough to make in a U-shape that hangs off the end of the duct tape. The thread should be long enough to be attached to a wire and then connected to a breadboard, and placed on one side of the duct tape. Then do the same thing with a second piece of conductive thread, but have the thread hang off the other end of the duct tape.
Step 3: Cut out 2 pieces of Velostat (one for each conductive thread) and cover thread with the Velostat. Then get a 3rd piece of Velostat which will be placed between the 2 pieces covering the thread. Folding the duct tape is the final step in making the flex sensor.It’s important to make sure the threads don’t touch in any way, this will cause a short circuit.
Step 4: After making the sensor a multi-meter can be used to measure the resistance of our sensor. By attaching the two terminals of the multi-meter to the two threads on the sensor a resistance shows up on the multi-meter display. This resistance changes as the sensor bends. As one would bend their finger, the distance between the fingertip gets closer to your palm. When the distance between the ends of the sensor get closer, the pressure changes.
As we are learned the code in lab 4 for ADC and PWM signal. I change the internal temperature sensor to the internal light sensor to control the frequency of the PWM signal, “adcch_set_input(&adcch_conf, ADCCH_POS_PIN0, ADCCH_NEG_NONE, 1); “. For the night LED will flash cause it have low frequency. and for the day you can see the solid light as the high frequency. Then we are set the while loop to display the pattern we want. below is the code PWM signal send out from the 7 pin of A3BU. Each pin connect to 110 ohm resistor then connect to the LED circuit. Here is a link to the full code we are use for our project. (we modified the code from the ADC internal temperature of A3BU in new example) .
The Motion Sensor used by our group detects any person or pet using infrared detection technology up to 20 ft away. The sensitivity of the sensor can be modified with a dial on the back. There is also a timing dial which affects how often the sensor will give an output based on detection.
This is a quick demo of our teams final project. In it you can see a quick run through of the basic functionality we implemented with close ups and reruns. We show our whole board and explain step-by-step what happening, and what’s to be expected.
Our final project was the Anagram Solver we have many interesting aspects to our project. Some of these high level aspects include:
Controlling the LCD on the A3BU
Asking the USER for Input
Flashing LED’s for correct/incorrect answers
Flashing LED for inputs
Generating results based on C programming
Although we have so many interesting features, one of our best features is the crazy light show! After exiting the program, the program flashes both the blue and red LED’s and the LCD backlight in a spectacular fashion. It is truly an amazing aspect of our project!
Our group project deals with an anagram device. We thought that since it is something many of us have done and apps that we use all the time on our phone it would be a good project. For this we had two different levels to choose from that would determine the difficulty of the problem to solve. Once the level is chosen then a word is given and your objective is to unscramble to word and make it correct by typing it out on the keyboard. If the correct word is spelled then the LED that is blue will turn on. If the incorrect word is spelled then the red LED will turn on. Also, for every input put into the device, the red LED will flash dimly. The code will also clear the board for you and allow you to pick a new level once the game is finished.
Overall, we would call our second attempt a success. Our original plan was to do a “Simon Says” game but we ran into many issues and were running out of time due to finals approaching so we decided to scrap the idea and go for the anagram.
Even with this slight hurdle we would call this project a great success.