Useful Links

Week 9

Tested both computer to Arduino and Arduino to computer communication using Python's serial library. Both are very intuitive and appear to function well. One thing to note is that the computer to Arduino communication can be rather slow.

Drove both the steering servo and ESC from a Raspberry Pi mounted on the Pi Car.

Set up and calibrated the ESC, Arduino, and remote control so that the remote control can drive the car. In this mode, the Arduino reads in the remote control signal and then feeds the ESC the corresponding pulse width. Additionally, it will later tell the Raspberry Pi what it is doing so that the Pi can transmit its intentions.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Create a script to read ESC and servo commands from the Arduino and broadcast them.
Test using the remote control to give a stationary Pi Car commands which will be transmitted to and executed by a mobile Pi Car.

Created an Arduino script that receives Serial inputs and theoretically drives the servo and ESC on the Pi Car.

Looked up a minimal amount about python's serial library which will be used to communicate with the Arduino.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Experiment with driving the cars.

Performed the mobile timing test with good results. The Pi Car could transmit information even when mobile in less than 100 ms.

In the interim, it was discovered that an additional wifi adapter would be necessary to connect the Pis to the internet as well as to each other. This feature will therefore likely be delayed until a different project.

Met with Dr. Zhang and the rest of the group to discuss how to physically drive the car.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Figure out how to program the cars to drive.

Mobile Test Results Mobile Timing Movie

Week 8

Installed Raspbian on all the SD cards.

Debugged the `setup.sh` script.

Synchronized the clocks across all the Pis (necessary to get timing results).

Performed the timing test. In this test, one Raspberry Pi (with IP address 192.168.1.3) received signals transmitted from two other Pis (with addresses of 192.168.1.2 and 192.168.1.4). The .4 Pi was approximately 1.5 meters from the .3 Pi and the .2 Pi was approximately 3 meters away from the .3 Pi. All of the Pis were sitting atop the same desk. The .4 Pi's signal was halted approximately halfway through the 30s test to ensure that the .3 Pi could still receive messages even with a changing network topology. The results were quite successful with messages being sent overall in well under 1 second (very comfortably under the original goal of ~ 6 seconds).

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Perform a mobile test of the Pi cars.
Look into connecting the Pis to the internet so that they can synchronize their clocks automatically.
Figure out how to program the cars to drive.

Timing Test Results

Formatted all three SD cards and flashed them with NOOBS.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Actually test the Pi Cars.
Setup the SD cards to test.

Debugged the setup.sh script.

Modified the Network class to use a Queue.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Actually test the Pi Cars.
Flash the SD cards we were given with the appropriate os.

Met with Dr. Zhang to discuss building a new Pi Car.

Found the parts we had available and ordered the rest

Budgeted the Pi Car over email

Performed a test to demonstrate that the Network class can transmit and receive data.

Used and debugged the `setup.sh` script. More debugging pending.

Met with Dr. Zhang to discuss progress.

Yak and Jacob will begin assembling a new car.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Actually test the Pi Cars.
Use the Queue object to allow for data transfer in the network class.
Flash the SD cards we were given with the appropriate os.

Continued documentation on code

Group Meeting

Started to work on the debug setting

Group assesment

Week 7 (Spring Break)

Looked through issues on the repository

Annotated 3 messaging classes

Started on a debugger

Created a `setup.sh` script to automate the setup process of new Raspberry Pis.

Changed the `Network` class so that it reads the machine's internet address so that it knows what to `bind` to (instead of looking in a .conf file). This means we no longer need to use a static ip (maybe).

(Hopefully) Fixed the termination of the listening process.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Actually test the Pi Cars.

Week 6

Reviewed progress with Dr. Zhang. It is her opinion that we should begin working with actual cars as soon as possible because there are liable to be unforeseen issues.

The demo would likely be more impressive with more vehicles. Thus, it would be nice to have Jacob and Yak work on actually constructing some cars.

Next Steps:

Actually test the Pi Cars.

Tried to test and debugged receiver Pi. Discovered some syntax errors and logged those to GitHub (will resolve in coming days/weeks).

Met with Professor Mell to give a progress update.

Could not find a second working Pi, Professor Mell said he will discuss it with Dr. Zhang.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Actually test the Pi Cars.

Week 5

Went to the PiCar lab for Monday meeting

Met with professor Mell to go over progress

Added some documentation to code

Continued documentation on code

Group Meetings

Got git set up and learned how to effectively use repository

Added documentation to the test methods.

Set up Yak with git.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Actually test the Pi Cars.

Weekly Friday meeting

Met in Urbauer lab to go over code

Added documentation to the tests and to some methods in the messages classes.

Merged all of the branches with master so that they are now up to date.

Met with other PiCar students to discuss progress.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Actually test the Pi Cars.

Week 4

Finished up most of the work for timing tests.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Actually test the Pi Cars.

Had class meeting and gave presentation

Learned more syntax for socket coding

Had meeting with instructor

Worked on doc strings and methods (see repository)

Met with class to give presentation.

Began work on timing tests to ensure messages send quickly enough.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Finish up writing the tests.
Actually test the Pi Cars.

Met with Dr. Zhang and rest of the group to give WiFi presentation.

Met with group to discuss way forward.

Set up git repository on Jacob's and Yak's computers.

See code contributions here: https://github.com/patricknaughton01/comm_scripts/commits/master

More Python learning

Started documentation on code

Group Meeting

Cleaned up log, website, and presentation

Set up repository, set up collaboration, and installed PyCharm to be able to push to GitHub

Read up on syntax for socket coding, plan to do more of this later

Group Meeting with TA

Completed the Broadcast method in the network module (see repository)

Week 3

Created a small tutorial on git, posted in Useful Links above.

Worked on Message classes. For specifics, see https://github.com/patricknaughton01/comm_scripts/commits/master

Next Steps:

Look at TODOs and build out more of the Network class functions.
Start creating documentation for the functions already written.

Built out some of the receiving functions in the Network class. Have not tested yet, not documented either.

Decided to use multiprocessing instead of threading because they offer abort capabilities.

Created a config directory to save settings for the Network. May be used in the final product instead of the package.

Next Steps:

Look at TODOs and build out more of the Network class functions.
Start creating documentation for the functions already written.

Experimented with the threading library and made an example in network.py.

Demonstrated 3 way communication successfully.

Created model and added to GitHub: https://www.draw.io/#G1nteipWO6p85XItbLYPe8M1n9dVy68YSa

Next Steps:

Flesh out model
Design and implement RTT test.

Challenges:

Debugging model.

Week 2

More Python learning

Continued reading the posted links and other research

Group Meeting

Watched a series of great in-depth tutorials on coding Python on a RaspberryPi

Group Meeting with TA: We experimented with and successfully implemented 3-way communication between PiCars

Worked on model for Python code

Watched Python tutorials

Made adjustments to the Gantt chart

In-class Meeting

Created two python scripts, send.py and recv.py to send and receive messages using python's built in socket library.

Configured the above scripts to broadcast to any device operating on the same network.

Created and updated a Github for the code.

Next Steps:

Designing a round-trip-time (RTT) experiment to determine how long packets spend in transit.
Define the model we want to use to send these packets.
Add in another Pi to test how/if that changes the network's capabilities.
Define a standard name for the mesh network.
Experiment with sending to just a subnet rather than any available IP address.

Challenges:

Effectively testing RTT
Designing an effective, consistent model.

Finished up presentation on Wi Fi.

Researched how to send udp packets with python.

Next Steps:

Experiment with socket library

Challenges:

Debugging socket

Met with group to discuss wifi adapter. Decided that we don't need it because it will not improve the success of our simulation. Still important when considering scale-ability to actual cars.

Used nmap to find all Raspberry Pi's in the LAN. Very slow (on the order of 10's of seconds).

Met with Dr. Zhang to discuss progress. Decided it was worthwhile to prepare a primer on Wi Fi both to help other groups get background on the project and to formalize some of our own knowledge.

A grad student mentioned the use of UDP (user datagram protocol) to exchange information. Good because it doesn't require an initialization handshake and transmits quickly. Python has a built in library (socket) that interfaces with this protocol. It also supports broadcasting to an entire subnet, potentially eliminating the need for nmap. Will research further.

Began presentation on Wi Fi.

Next Steps:

Complete presentation
Experiment with socket library
Calculate maximum allowable delay given car speeds (~5 m/s) and Wi-Fi range

Challenges:

Debugging socket
Getting reliable latency requirement estimates

Finished the presentation and cleaned up the Gantt chart

Continued reading the posted links and other research

Working a little bit out of order but experimented to see how we can ping all Pi's on the LAN efficiently. It appears that using an nmap package (https://www.raspberrypi.org/documentation/remote-access/ip-address.md) might work.

Given the above information, it might be wise to reorder our Gantt chart to make sure we can ping multiple Pi's on the same network before we start trying to send specific information to ensure that our solution is scaleable.

Installed babeld package and found out that there is very little support for it. Likely will not use.

Discovered that the Raspberry Pi's built in WiFi only can support 2.4 GHz (https://liliputing.com/2016/02/raspberry-pi-3-to-feature-on-board-wifi-bluetooth.html), meaning that if we want to be more accurate (adhere more closely to the 802.11p protocol), we should buy an adapter that supports 5 GHz. Will discuss in meeting

Next Steps:

Install nmaps and see how well it works
Set up a mesh network with another Pi to ensure that we can broadcast more than one way

Challenges:

Debugging nmaps
Minimizing time taken to ping everything.

Finished the majority of the Gantt chart during our in-class meeting.

Began work on the presentation.

Began work on the Gantt Chart to distribute the work load.

Began the presentation for the class presentation.

Week 1

Watched assorted videos on learning Python

Read through more of the links

Attended group meeting and discussed group goals.

Continued research into materials and read linked articles.

Began to brush up on Python for future coding we will do

Successfully pinged one Raspberry Pi from the other one over an ad hoc network.

Configured each Pi to create an ad-hoc network on startup and assign itself a static IP address.

Relevant files:

etc/network/interface
etc/rc.local

Next steps:

Exchanging strings between both Pis.
- The following link/module may be helpful: https://stackoverflow.com/questions/34548037/two-raspberries-communicating-each-other

Confirmed that ad-hoc networking is feasible. Used one Raspberry Pi to create a Wi-Fi access point that my phone could detect.

Additionally, no Wi-Fi adapter was necessary because the Raspberry Pi model 3 comes with it's own native Wi-Fi capabilities.

Next steps:

Getting both Pi's to create ad-hoc networks
Ping one Pi from the other

Got a key to the lab so that we can access materials.

Met with group to discuss objectives and potential challenges.

Acquired 2 Raspberry Pis to experiment with in order to see how easy it is to establish ad hoc communication.

Met with Dr. Zhang to discuss progress.

Discussed potential for different demos. A "mirroring" demo may be more feasible if other groups are not as successful as hoped.

Met with other groups to see their progress.

I attended the first weekly meeting. We clarified our end goals for the piCar project and talked over how we will accomplish our goals.

I read some articles on the 802.11 modules and I also read through the thesis on the DriveIt communication between Raspberry Pi cars.

Found yet another WiFi adapter, this one suggested by a paper specifically about using the Raspberry Pi as an "on board unit" for DSRC in a VANET. This specific adapter, at least upon initial inspection, looks like it would be a good candidate because it has Linux support, can run in ad hoc mode (CTRL-F the documentation for ad hoc, it specifies how to set it up), and runs in the 5GHz band with backwards compatibility for the 802.11a protocol. Additionally, the authors of the paper successfully used it to establish communication on a Raspberry Pi, meaning this is possible.

Adapter: https://www.amazon.com/TP-Link-Wireless-Adapter-Archer-T1U/dp/B016K088UC

Adapter documentation: https://images-na.ssl-images-amazon.com/images/I/C1BISG1QKyS.pdf

Paper: http://www.ijste.org/articles/IJSTEV2I10148.pdf

Just found a Wi-Fi adapter compatible with the 802.11a standard. It does not come with a driver on the latest version of the Raspberry Pi, which could actually be a good thing because it means we can compile the driver ourselves (modifying open source designs to suit our needs). Links to the adapter and tutorial can be found at the end of the post.

http://us.edimax.com/edimax/merchandise/merchandise_detail/data/edimax/us/wireless_adapters_ac600_dual-band/ew-7811utc/

This is available on Amazon (https://www.amazon.com/Edimax-EW-7811UTC-Dual-Band-Connectivity-Exceeding/dp/B00FW6T36Y/ref=sr_1_1?ie=UTF8&qid=1517199327&sr=8-1&keywords=AC600+Wireless+Dual-Band+Mini+USB+Adapter+EW-7811UTC) for about $16

Tutorial: https://layereight.de/raspberry-pi/2016/08/25/raspbian-rtl8812au.html

Link to github for open source driver: https://github.com/gnab/rtl8812au

Reference: adapters that work with Raspberry Pi: https://elinux.org/RPi_USB_Wi-Fi_Adapters

Based on this article (http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6060057&tag=1), we should be able to use an 802.11a driver to mimic a worst case scenario 802.11p driver. The paper concludes that with minor software adjustments,

VANET solutions that are validated using this approximation will also work on real hardware with better signal quality. As long as experimenters are aware of the limitations of the presented solution, it can be successfully applied as a cost-effective tool for VANET research.

We therefore need not find an 802.11p module - a more common 802.11a module will do.

Unfortunately, finding an 802.11a module is also surprisingly difficult. However, an 802.11n module should be able to operate in 802.11a mode because they share the same frequency (5GHz). This means an 802.11n module should suit our needs, as long as we can modify the device driver to make the minor adjustments the above paper discusses. Directly below is an example of such a driver.

https://www.canakit.com/raspberry-pi-wifi.html

In addition to supporting 802.11n operation, the dongle must also support ad hoc mode. This is because that seems to be the best way to set up a network mesh among multiple raspberry pis. Instructions for doing so can be found at the following link:

http://www.ericerfanian.com/mobile-mesh-networks-with-the-raspberry-pi-part-1/

Using an ad-hoc network mesh seems to be the best available solution. DSRC/WAVE, which nearly every source cites as the way to send emergency communications between cars, is an ad hoc network (https://www.hindawi.com/journals/jat/2017/2750452/). Such a network does not rely on external routers, so even if the cars lose internet access, they can still communicate with one another.

Link dump of all the papers/modules I've found regarding this project.

https://www.hindawi.com/journals/jat/2017/2750452/
http://sandhill.com/wp-content/files_mf/whitepapervehicle_to_vehicle_communicationeinfochips.pdf
http://www.promiot.com/v2x/vtx-201
https://www.ietf.org/mail-archive/web/its/current/msg00935.html
http://dimme.net/tag/raspberry-pi/ <-- This is the master's thesis that's really good/thorough
https://www.unex.com.tw/products/dsrc-v2x/technology/v2x-on-board-unit/1609x-stack/detail/obu-201u
https://www.academia.edu/20878754/Accessible_customizable_high-performance_IEEE_802.11p_vehicular_communication_solution?auto=download

Author: Patrick Naughton

Date: 1/26/2018

Link to modification article. Hopefully we can use this to modify an existing 802.11a (WiFi) module to fit our needs.

http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6060057&tag=1

Author: Patrick Naughton

First log

Pi Car Comm Log

Contents

Useful Links

Week 9

Driving

Motor Driver Script

Mobile Timing Test

Week 8

Timing Test (Finally)

Flashing SD Cards

Fixing Bugs

New Pi Car

Testing and some bugs.

Group Meeting, Documentation, and Debug Method

Week 7 (Spring Break)

Repository Issues

Setup Script and Minor Edits

Week 6

Group Meeting

Attempted Test

Week 5

Group meeting and documentation.

Group Meeting and Documentation

More documentation.

More documentation.

Starting on documentation.

Week 4

More work on tests.

Presentation and Instructor Meeting

Class meeting and work on tests

Meeting and Work on Classes

Group Meeting and Documentation

Repository and Socket Coding

Week 3

Message Classes

Network Functions

Threading experiments

Three Way communication and the model

Week 2

Group Meeting and More Research

Raspberry Pi tutorials

Friday Meeting/Python Learning

Broadcasting Two Way Communication

Presentation

Meeting, NMAP, and Research

Gantt Chart, Group Meeting, Presentation, and More Research

Pinging all Pis and the necessity of a wifi adapter

Weekly Meeting

Project Info

Week 1

Started Learning Python

Yak Week 1 Work

Pinging Over Ad Hoc Network

Ad-Hoc Communication

Getting Materials

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