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PQ Robotics Club

PQRC Meetings

Below are the meeting summarys:


3D Robotics Tour - 31 July

Flying High at Otay Mesa

The PQRC group met at the 3D Robotics facility in Otay Mesa for a tour.

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The tour started at 11a.m. and lasted about an hour.

The crew at the right is: Trevor Miller, John Wolf, Steve Berneberg, Joe Bolerjack, and Jeff Parker.

Our tour guide was Justin Cunningham, flight test engineer for 3D. We started the tour in the design and engineering room. The facility is first class with 3D printers pumping out the latest designs. 3DR has many custom builds for customers with money. The designs we saw were very complex and leading edge. The quadcopter industry is close to a boom as the day approaches when the FAA rules for commercial use get issued. 3DR is poised to meet the demand.

Next we went into the cavernous manufacturing and shipping warehouse. The huge room handles the incoming parts, both assembled and those requiring assembly along with quality control and test engineering.

The photo on the left shows several vehicles developed in the past. We also saw there latest product, but I didn't include those images here for proprietary reasons, but the are distribution a very large, heavy-duty rover with the latest autopilot that is awesome.

On the right is an example of a hefty copter with six motor arms and a camera gimbal system. We discussed many of the technologies 3DR relies on to make its products competitive. They have a working relationship with Michael Oborne who is probably the best programmer of flight control software available. Since 3DR's machines use GPS, autopilot gyros-accels-baro integrated into one package, the Mission Planning software Michael writes really gets a fully functioning ground or air vehicle to act like the hardware used by the military or commercial use. Waypoint navigation, altitude control, attitude adjustment, and multi-mode operation matches up with the Spektrum radio equipment usually used on 3DR's products. 3DR sells kits and ready-to-fly vehicles. They supply the radios and receivers, not to mention, all the little piece part ones needs to stay in the game. It was a great tour. Check out 3DRobotics.com for more information.


Fourth Official PQRC Meeting 14 May, 2014

Bring Your Demo

Click here for the PowerPoint slides.

Fun night. Everyone bring a project description and/or demo to share.

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The meeting was held at Jack Wolf's garage at 6:30pm, 14 May, 2014.

There were only four at the meeting due to the fires in San Diego. The whole city was under attack, and the nine fire that were evenly distributed across the county looked suspeciously like arson, made all of us very nervious. Of the four present, Kelly presented a class project she had done in the past where she used a microprocessor to drive an inductor with a PWM voltage to four different levels. In the inductor was a ferrite plug a little less than 1/4 of the length of the inductor's height, standing on end. Attached to the plug, she glue a wooden indicator that moved to the different levels caused by the magnetic force on the plug. She had wired up two switches to allow raising and lowering of the indicator.

My project demonstrated the use of a Python program to toggle a LED on and off by sending serial data to an Arduino Uno with a design shield on top where the LED was wired. I had a Bluetooth module mounted on the board as well, but I couldn't get it to work. If so, the Arduino could have been free standing. I'm convinced that Python is import for those indulging in embedded processing, because this language installed on processor like the Raspberry Pi or your laptop becomes the traffic cop in the middle that can direct messages to and from servers, both local and remote, to all available connected I/O more effectively than any other approach. The processing power is unlimited, so Python can carry the burden of many tasks that would otherwise load down the outboard sensor and controller processors like the Arduino. The screen shots of the Python program, Arduino sketch, and the command line window that runs the Python program are shown in the attach slides for the meeting.

Two other items have come up, one during the meeting and the other the next day at National Univ. First, I'm trying to secure a tour at 3D Robotics for 6 June. I contacted them this today (16 May) and sent in the formal request. I'll let you know if it goes through. Second, and maybe more interesting, is while at a meeting at NU for the new department School of Engineering and Computing I talked to their robotics professors. I told them about out club and the gist of the discussion was: they suggested we have the meetings at the engineering building where students could have access and we could expand the experience by using university assets. This not only means a first class room to present topics, but we could use their lab and film studio. This should open the opportunity to have highly qualified speakers come to our meetings to discuss all aspect of hardware and software used in embedded processing and physical computing!

I was blown away by the offer. It's a great opportunity to further advance the club, expand our experience, and be part of a broader education for NU students. As part of this new department change, the university has joined forces with D&K Engineering, which will be providing a entrepreneurial avenue for the students. They are an ideas from conception to production company and add a real world experience for students. We will have access to their experts! This could really lead to something exciting. Stay tuned.


Third Official PQRC Meeting 16 Apr, 2014

Using Ethernet to Reach the Internet

Click here for the PowerPoint slides.

This meeting focuses on placing an Arduino to the Internet as a server via an Ethernet shield. Will also address taking data from a sensor and data-logging to an SD card or monitoring on a webpage or third-party app.

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The meeting was held at Jack Wolf's garage at 6:30pm.

The meeting commenced with the following in attendance: Kelly, Sandra, Bob, Alfredo, Joe, Jeff, and Alex

The focus was on putting the Arduino on the Internet with its own IP address. We went through the slide show and details out the various protocols for the Arduino to send an HTML page to anyone on the Internet to used a browser to issue the IP address. The page had a form with three buttons and a slide to control to turn on and off three LEDs and provide a tone frequency that would sound. The Ethernet Shield on the Arduino also had a temp sensor to update every five seconds. Ech time a request was send from the client, the temp would update on the HTML page.

I showed the group WireShark in action, which is an app that sniffs an Internet connection and records all the protocol traffic on the network. This way you can see the message packets that are always active. The MODEM constantly checks on the members of the LAN and traffic entering from the outside is also recorded, so you can see all the HTTP Requests when a URL is requested.

RTCOnce the Ethernet to IP system was demo'd, I pulled the Ethernet Shield and replaced it with a proto-shield with a Real Time Clock (RTC) and a light intensity to frequency sensor to demo how to get timestamps into a sketch and how to convert the frequency output of the light sensor to value that represents counts of wavelengh. Now the range of interger values can be scaled against light intensity.

I also demo'd a couple of Sumo bots on an official Sumo Bot ring (30 inches in diameter black circule with a 1 inch wide edge painted white for the bots to detect the edge. These devices are made by Pololu and are called Zumo Bots. They have a piezo speaker, 3-axis accelerometers, compass and motor drivers for the tank tread style drive. In the fight-mode they speed up when they hit the opponent or randomly shoot across the ring to push the opponent out of the ring if they happen to hit it. ZumoI added an IR sensor to one of the bots to see if it would have an advantage. If the sensor detects the opponent, the bot would race forward. It turned out that only when the bots were head on would the IR bot see the other one, so there wasn't really an advantage seen.

We didn't get to the SD card demo as time ran out. The Ethernet Shield has an SD card reader on it as well, but the share the SPI bus to the Arduino, so you have to run separate software to use the SD card. I had tested the feature prior to the meeting and the SD Library sketches worked as advertised. The SD card is the heart of data logging sensor data attached to the Arduino. I'll set something else up later to demo data logging.

We wrapped up the meeting with a vote to visit Genentech, Inc for our next tour to see a real automated factory in operation. The next meeting will concentrate on individual project demos.

Code Vortex

Second Official PQRC Meeting 12 Mar, 2014

Using Classes in Sketches

Click here for the PowerPoint slides.

The focus will be how to write and use C++ Classes in Arduino sketches. Demo of Morse Code circuit. Minutes of the meeting to follow here after the meeting.

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The group will meet at Jack Wolf's garage again.

The demo is a circuit that has a speaker and LED to hear and see Morse Code coming from the software. A message can be typed in the Serial Monitor window that produces the Morse Code sound and blinks the LED, but also prints out the code symbols and the letters the code is sending. The bulk of the heavy lifting in the sketch is done in a Class attached to the main code.

After this intro to using Classes, Darius Miller will expand on this idea and show us more about how Classes are created using the DTMF sketch from the first meeting to deconstruct it into various Classes to simplify the main program.
Click here to get to the Minutes of the Meeting and various reference presented during the meeting.

ATX Pwr Supply

First Official PQRC Meeting 19 Feb, 2014

Physical Computing

Click here for the PowerPoint slides.

The focus is on going directly to the Arduino code and demo hardware and see how the sketch works with the hardware.

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The group met at Jack Wolf's garage not unlike other famous California garages known for great works.

The DC motor demo consisted of regulated power supply providing +9 volts for the motor controller board and the DC motor on the carriage. An Arduino Uno is used to control the sled speed and direction. The motor moves a sled back and forth on a rail pulled from an Hp printer. There were IR interruptor sensors at each end that detected the presents of the sled and reversed the motor direction. The software can easily be modified to make the motor ramp up and down in speed. The end detection sensors actually each have two separate sensors to fine tune the sensing. Only one in each sensor was used. The S/W just looks for a change on a pin from low to high each polling interval, so there could be a time lag that might affect the precise position if the sled is moving fast. The S/W could be modified to use interrupts to more quickly respond.

Next, a TI LaunchPad board with a C2000 chip was used to demo powerful 3-color LEDs. One version uses a GUI interface on the PC and the other was a stand-alone board with a capacitive sensor to adjust the LEDs. A 12V power source is required for the LEDs Booster board with the LEDs. The C2000 board runs off a 9V battery or USB connection for power.

Next a demo of a system to detect DTMF tones over a telephone line to operate 8 triac switches capable of 120V/15A. A tone generator box was built to provide test tones during check out of the system. The main circuit consists of a DTMF detector that provides 4-bit data to an Arduino Mega board. These bit tell the software which of 16 pushbotton on a keypad were pushed. A normal phone uses 12, but the original design included four for label A thru D. There extra buttons were used to define modes of operation. The A key is used for an access code. The B key is used to enter the switch select mode. The C key is used to show the status of the 8 switches either on or off. The D key is use to end the session and can be used to turn off all switches at once.

An additional circuit was added to the prototype area of the triac board to decode and latch the switch selection. This action operates the switches. The latch operate in a toggle mode. When the * key is pushed, the selected switch is turned on and when the # key is pushed the selected switch turns off. The hardware is really just using the same path, but in the second case toggles the switch off.

When the system is meant to be operated remotely over a telephony line, a voice chip supplies the sequence needed to operate the switches in parallel with what would be seen on the PC screen during normal operation so the user knows what to next and hear the switch status. There is a small board instructed by the Arduino to "speak" each command back into the phone line. There is a special circuit called the DAA that brings the rings tones in, goes off-hook to start the system, and transmits the voice commands back to the caller.