Team:USTC/Tutorials
Thank you for using the SPRING, a fast optical interference detecting device.
Before you using SPRING, please carefully read this instruction manual to fully understand the operations and the attentions.
Materials
To accomplish SPRING, you need prepare those material showed below:
| Materials | Number | Price in estimation($) |
|---|---|---|
| 12 in 1 display | 1 | 92.08 |
| CSI Interface Camera | 1 | 13.88 |
| Camera Bracket | 1 | 1.42 |
| 3V laser head | 2 | 0.31 |
| 5V laser head module | 2 | 1.73 |
| Arduino UNO R3 | 1 | 4.67 |
| Universal circuit board | 5 | 0.41 |
| Breadboard | 2 | 1.75 |
| Dupont line | 15 | 4.25 |
| 12V lithium battery | 1 | 15.72 |
| 12.6V 3A Chargers | 1 | 6.06 |
| DC-DC step-down module | 2 | 5.04 |
| PP board | 1 | 7.71 |
| Miniature hand drill | 1 | 20.46 |
Protection Guide
When you are making NDM, many tools are needed, as well as touching bacteria solution. Consequently, we provided four recommended protective measures for everyone. Please pay attention to personal safety when doing experiment:
- Level A: Fundamental protective measure when producing NDM and conducting experiment. You may wear lab coat. When conducting experiments and assemble NDM, level A should be satisfied always.
- Level B: In level B, personnel should not only wear lab coat, but wear nitrile gloves or latex gloves, which are necessary when touching bacteria solution. This procedure is the first step for detection.
- Level C: Level C is the standard protocol for personnels when drilling. In addtion to level A, you should wear goggles. Goggles would protect your eyes when you are drilling plexiglass. And please do remember ROLL UP YOUR SLEEVES to prevent possible hurts and DO NOT WEAR GLOVES because it is not convenient when drilling.
- Level D: This is the most complicated protective measure for spraing painting procedure. One should wear lab coats, along with goggles, masks and gloves to toally protect oneself considering extreme pungent odor volatilizing when painting.
Tools
- Drill is used for cutting acrylic materials for assemble bracket.
- Electric soldering iron, for welding electric circuit.
- Glue gun is needed for adhesion between each other acrylic materials.
Display module
The display module contains 12 in 1 display with processor and buttons. Users are able to control the power, contrast and other display effects through buttons beside the display.
Raspberry Pi
Raspberry Pi, is the main hardware module that can take photos or videos of interference fringes, then our software analyses them or transmits to your PC. we can see the results on the screen.
Circuit Elements
- Transformer: The responsibility of transformer is to drop voltage 12V produced by lithium battery to 5V, which is needed to supply cooling fan on Raspberry Pi and laser beam.
- Breadboard: Many solderlessly electronic circuits tests will be conducted on breadboard.
- Lithium-polymer battery: Provide power, 12V, 10000mA·h.
Optical Path Elements
The schematic figure of optical path is based on Michelson interferometer, to get more principle of optical path in SPRING, please refer to: Project-SPRING
Here we will introduce elements that are indispensable for interference patterns formation.
- Webcam, containing CCD(charge-coupled device) image sensor, is able to capture picture, mainly for interference pattern capture.
- Laser, wavelength: 650nm, 5V power supply
- Expander is to expand the diameter of the laser beam. Two reasons are required to expand beam diameter. On the one hand, a larger diameter of the laser beam could avoid laser focusing on detecting film, preventing the possibility of film burned. On the other hand, laser beam would cover the film for better detection.
- Beamsplitter combination, consists of three mirrors, a 50% reflection - 50% transmission beamsplitter(50%(R)/50%(T) in brief), a 80% reflection - 20% transmission beamsplitter(80%(R)/20%(T) in brief) and a 10% reflection- 90% transmission beamsplitter(10%(R)/90%(T) in brief). 1)50%(R)/50%(T) is in the front of picture. The reflection light will project to detecting film , while the transmission beamsplitter will continue going to reflection mirror. 2) Then why do we need The 80%(R)/20%(T), along with 10%(R)/90%(T)? Actually these combination is really important to decrease the relatively high intensity reflected from reflector. Much higher intensity from reflector will not fit the formation condition of interference pattern. 80%(R)/20%(T)+10%(R)/90%(T), approximately allowing 18% light approach reflector, are combined together on the bottom of the picture.
- Reflector, a necessary element for interference pattern formation.
- Sample trough with film, interacting with reflector to form interference ring.
Sample Trough
Our sample trough or sample box is designed based on the most proper size.
In the middle lies the empty part, which can be covered by film.
These are our clips, there are two kinds of clips respecitvely used for different shape of film.
And in order to adjust optical device on the same plain, you may need a plexiglass base to produce. You can produce your own base followed the drawing above.
Film Preparation
To see more about our ways to find final film through candidate, please refer to Modeling-Film Candidate.
Our film will be prepared in several processes illustrated below:
Coating film with polylysine
Add approximiately 400 ul 20ug/mL polylysine on the film, and store the film at 4 degree celcius for more than 4 hours. After 4 hours, absorb polylysine and then wash the film by PBS buffer. Note: polylysine can be recycled.
Adhesion Assay
Add 200 ul bacteria solution on film about 100s. Note: bacteria grown should be in steady state, and you should dilate bacteria and let its OD(600) approximiately reach 0.05
Operate Optical Path
Operating optical path within 100s would be highly recommended for users. To get the best images, you should observe and get fringes parallel to y axis of screen as possible.
Observe and Record
The measurement period is about 300s. Consequently, we recommend users to take a series of images each 10s during the beginning of 300s.
Build your electric circuit
Prepare RaspberryPi
The Raspberry Pi is a low cost, credit-card sized computer that plugs into a computer monitor or TV, and uses a standard keyboard and mouse. It is a capable little device that enables people of all ages to explore computing, and to learn how to program in languages like Scratch and Python. It’s capable of doing everything you’d expect a desktop computer to do, from browsing the internet and playing high-definition video, to making spreadsheets, word-processing, and playing games.(https://www.raspberrypi.org/help/what-is-a-raspberry-pi/)
The module we used is Raspberry-PI 2B, and you can buy from www.raspberrypi.org
First, write the system into a TF card and then put it on your Pi
The system RASPBIAN is recommended. Attention: TF card and SD card are different. TF card also called Micro SD card. You can download the updated system from www.raspberrypi.org
Then, begin to write. You should prepare a TF card, preferably a high-speed card is recommended above Class4 because the card was a direct impact on the running speed of Raspberry-Pi.
Get an Installation Tools win32diskimager (under win7), download at this site
Connect the TF card to your PC. Unzip the downloaded zip file debian system to give image file.
Extract and run win32diskimager Tools.
Select debian img file, and select the SD drive letter under "Device", then click "Write".
Then, you’ll see “Write successful”.
Connect and Power on your RaspberryPi
You should power your pi with 5 volts using a micro-usb line. Remember to connect your keyboard and mouse to pi first, because you can’t make anything without them.
Attention: don’t forget to power on the mini fan on the Raspberry-Pi due to too much heat generated.
Then connect the display device.
And we need to connect the camera.
Finally, get started!
Get started
First, you should update your RaspberryPi. Just click the image of monitor. And then enter “sudo apt-get update”.
Then enter “sudo apt-get install luvcview”
After installing the software, restart your RaspberryPi and enjoy your journey with SPRING now!
How to use Raspberry Pi?
I. Power on the screen,and then the raspberrypi.Power on the mini fan.
Click this one:
II. Enter “luvcview” andthen press ”enter”
III. After enter “luvcview”,Move the table to see the “take a picture!!” Then, click this one. You canclick it for many times.
IV. After get pictures, youcan transfer the files to your computer via WLAN adapter.
First, you should restart the “networking”.
Enter “sudo /etc/init.d/networking restart”
You will see this.
You should memory the “bound to XXX.XXX.XX.X” in your mind.
V. Then ,you shouldinstall the software “FileZilla”.
Open it ,and enter ”sftp://XXX.XXX.XX.X”
User name is “pi”
Password is “raspberry”
Normally , the pictures are in /home/pi .
Just drag the file to you computer.
Build your BOX
As is showed in the following picture, there is a clapboard inside the box, above the electric circuit part.
Oh, remember all parts should be fixed with hot-melt adhesive (hot glue), in order to maintain stability.
This is hot glue gun. The gun uses a continuous-duty heating element to melt the plastic glue, which may be pushed through the gun by a mechanical trigger mechanism, or directly by the user. The glue squeezed out of the heated nozzle is initially hot enough to burn and even blister skin. The glue is tacky when hot, and solidifies in a few seconds to one minute. Hot melt adhesives can also be applied by dipping or spraying.
Now, let’s see how to build it.
First, bond surfaces of your part and the workbench together. Look at the following picture, pay attention to the white thing. Yes, that’s it.
Then, stick the optical part with the workbench. Look at the following picture carefully.
And in order to make it easy to adjust the position of the film, we invent a little sliding rail.
As for the clapboard inside the box, we invent a removable device. Actually, it’s just a pair of supporting plates. Notice the left of the following picture.
In this way, we can put the electric circuit part on the supporting plates directly.
What's our tool when cutting acrylic?
