Final Project: Code

The goal for the device will be to use two servo motors in sync to move the arms of the device from vertical to a position about 30 degrees from vertical and then return it to the original position. This process will be repeated for a predetermined count. The initial prototype will only have one setting but my hope is that the final product will let the user choose a number of repetitions ranging from 5 to 35 by increments of five.

Possible Sources of Code

I was able to find basic instructions for programming the Arduino to control a servo motor while checking out the servo motors available from their store. The instructions can be found here. On the page they also mention that ” Note servos draw considerable power, so if you need to drive more than one or two, you’ll probably need to power them from a separate supply (i.e. not the +5V pin on your Arduino).”

In the post discussing my electronics purchases I expressed concern that I would need an additional power supply for the servo motors. Their explanation makes me feel a bit more hopeful, as I am only planning on using two servo motors.

Final Project: Device Frame

Below is the initial doodle I drew while at work and envisioning the structural construction of the device.










After the discussing the idea with parents and friends I believe that it may increase stability of the Rita Shaker if add guide grooves that would direct the motion of the arms. This will hopefully restrict any possible wobbling.

Tomorrow I plan on visiting home depot to find parts for the construction of the base, the arms, the guide grooves, and the holder for the shaker.

With regard to the actual shaker, I am going to use one of the two types that we currently use at Chili’s.












I’m leaning towards using the one on the left because it is made of plastic instead of glass. Not only would this decrease the fragility, but also the overall weight the servo motors would be required to move. The heaviness of materials will also heavily factor into my choice of materials for the frame.

Final Project: Electronic Supplies Ordered

The following are the list of of supplies that I have ordered to build the electronic portion of the device.

Arduino Rev 3 Starter Kit : The Arduino Uno Board was already supplied in lab but I am required to purchase one for another class I am currently taking so I decided to buy this kit so I also have the bread board, holder, and wires for use in this project.

Futaba S3003 Servo Standard (2): After investigating several different models of servo motors I settled on this one based on reviews and torque provided.

Microtivity Push-and-Lock Button Switch: I am purchasing with the desire for an on/off switch in mind but also with further development for different shaking intervals.

Wall Adapter Power Supply 9VDC 650 mA: I thought about using a battery adapter but decided on the wall adapter because of not wanting to purchase large quantities of batteries if this proves to be of practical use for my job.

Arduino Motor Shield R3 (Data Sheet): I am planning on trying to wire the device without this shield first. If I am unsuccessful I want to have the shield on hand.

I am still not sure if I am going to need an additional power supply for the servo motors or if I am going to be able to simply draw the power from the board.

Final Project: Plan of Attack

The plan for completing the project is as follows:

Sunday 4/22
Finalize List of Electronic Components and order them. (Accomplished)

Visit home depot to find hardware for contraptions body

Monday 4/23
Investigate possible code for programming device.

Wednesday 4/25
Electronic parts should arrive.
Begin testing with code.

Friday 4/27
Assemble frame and connect to arduino. Take video of this for benchfly.

Saturday 4/29
Run tests so I have time to tinker if it fails to work as desired. Work on instructible entry.

Sunday 4/30
Refine device if needed and take data for figshare.

Following week

Refine the code and make adjustments to the physical aspects of the device. Also, I hope to improve the aesthetics of the device.

Final Project: Brainstorming

This past weekend I went over to my parents’ house to have a brainstorming session concerning the final project with the Arduino board. We began by discussing what may possibly interest me and what may also be feasible with regard to the time constraints. After relating the story about the light system for the bike, the conversation turned to what could possibly be of use to me. I stopped to think of what annoys me most in my life and my mind quickly leapt to the current promotion going on at my work. I am a bartender at Chili’s Grille & Bar and we are currently halfway through another one of our many margarita contests. These contests necessitate my making a great deal of margaritas during my shifts. For the most part these are not that time consuming, however, the margaritas made with fresh lime juice necessitate vigorous shaking that varies from 5 shakes to 32 shakes. Now, simply making one of these is not a difficult ordeal, but when a server rings in five of them during the rush it can be very stressful and physically taxing to accomplish.

During these contests I always daydream of having a device that akin to a blender that could shake these drinks for me, while I focused on another task. I decided that I would investigate the possibility of constructing and programming such a device with the use of the Arduino board. After examining the Arduino store it appears to me that this is a distinct possibility. Some of the components that I believe may be of use to me during the construction are listed below.

Box for Arduino

Arduino Motor Shield Rev3

Servo Module (Possibly 2-3)

I just became aware that to but components directly from the Arduino store may be cost prohibitive as the shipping costs are exorbitant. After browsing through the page where they list their licensed distributors, it appears that Adafruit Industries may have the most comprehensive set of components from which I could choose.

After looking at the sites and thinking about shipping costs it dawned on me that I should check out, as I have a Prime membership with them and their products tend to be less expensive in general. (possible components to buy)

Wall Adapter Power Supply – 9VDC 650mA



Lab 11: OpAmps

The goal of this lab is to investigate the uses of OpAmps.


Check Power Supply:


+ 12 V Power Supply : 11.97 V

-12 V Power Supply: 18.60 V

5 V (TOP) Power Supply: 5.011 V

5 V (BOTTOM) Power Supply: 5.011 V

DO NOT USE HeathKit due the malfunctioning -12 V Power Supply

Bread Board w/ Power Supply:

+ 12 V Power Supply : 11.77 V

-12 V Power Supply: 12.04V

5 V  Power Supply: 5..158V


Looked at voltage follower on hyperphysics and the voltage follower on falstad applet.

Voltage Follower

OpAmp Power Supply Connections

I used the diodes in the above diagram where others did not. It does not make a difference in the oscilloscope readings but rather is a safety measure to protect the opamp.

Voltage Follower


Voltage Follower











I was able to get identical waveforms.

Oscilloscope Reading Voltage Follower

Zoomed in and found breakdown of waveform around 7500 H


Oscilloscope Reading at 6844 Hz




Oscilloscope Reading at 7985 Hz


Oscilloscope Reading at 12145 Hz

Summing Amplifier

Summing Amplifier

Summing Amplifier


measure input from function generator (channel 1)

measure output (channel 2) (inverts and adds)

Oscilloscope Reading from Summing Amplifier


Lab 10: NMOS/FET & Digital Logic



2N7000 Transistor

270Ω Resistor





Wire Jumper Kit














The goal of this lab is to construct various types of logic gates with 2N7000 NMOS transistors. I began as usual by forking the repository from Dr. Koch at 2012-Physics-308L-Lab-10-NMOS. Brandon had some difficulties with getting his to fork and I had an issue with cloning the repository to the desktop. After consulting with Dr. Koch, he checked the GitHub twitter feed and found that many people were having difficulties with GitHub at the moment. When I needed to compare my setup to Dr. Koch’s I instead just looked at the photos directly on GitHub.

Below is a schematic of the 2N7000 NMOS transistor found here.









For this section I constructed a NOT gate and then measured the drain source current and the voltage after the resistor. In the setup the green wire is connected to the gate of the transistor.


Drain Source Current: 0 mA (originally measured 12 mA b/c was picking up current going to LED)

Voltage after resistor: 4.953 V (2.044 V w/ LED wired in)

NOT Gate - Source: False / Output: True












22 mA

.052 V

NOT Gate - Source: True / Output: False










The above voltage readings make sense because when the source is is true, then the output will be false. The NOT gate makes the output the opposite of the input.


In this part of the lab we constructed a NOT NOT gate from two 2N7000 transistors, two 270 Ω resistors, and two LED.

Right LED ON/ Left LED OFF:

Original Resistor: 2.044 V (Due to LED draining)

New Resistor: .091 V

NOT NOT GATE- Source: False / Output: False

Right LED OFF/ Left LED ON:

Original Resistor: .082 V

New Resistor: 2.038 V

NOT NOT GATE- Source: True / Output: True











Through the use of two transistors it is possible to construct a NOT NOT gate. This is because the first transistor makes the output the opposite of the input. The second transistor makes its output the opposite of its input (the output of the first transistor. This results in the final output being the same as the initial input.


The final part of the lab instructed us to construct an NMOS NAND gate based on the following schematic found on wikipedia.


Below is a truth table for a NAND gate that can be found here.


In the setup yellow and green refer to the the wires leaded to the gates of each 2N7000 NMOS transistor.

Yellow 5 V/Green Ground:

Current: 0 A

Voltage: 5.006 V

NAND Gate- Green Source: False, Yellow Source: True / Output: True

Yellow Ground/Green Ground:

Current: 0 A

Voltage: 5.006 V

NAND Gate- Green Source: False, Yellow Source: False / Output: True

Yellow Ground/Green 5 V:

Current: 0 A

Voltage: 5.006 V

NAND Gate- Green Source: True, Yellow Source: False / Output: True

Yellow 5 V/ Green 5 V:

Current: 23 mA

Voltage: .145 before 1st transistor (.093 after first transistor)

NAND Gate- Green Source: True, Yellow Source: True / Output: False










The use of many of NAND gates in sequence would not be ideal because each successive transistor draws more and more current. This would be impractical in a real world setting.



Dr. Koch

Wikipedia articles on NAND gates.